Merge "Convert junit4 to junit5"

36 files changed, 496 insertions, 513 deletions

diff --git a/core/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java b/core/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java
index 35139bfe4..773923444 100644
--- a/core/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java
+++ b/core/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2019-2020, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021-2022 Bell Canada. All rights reserved.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
@@ -193,7 +193,8 @@ public class ApexEngineImpl implements ApexEngine {
     }
 
     private void updateTaskBasedOnStateOutput(AxPolicyModel apexPolicyModel, Set<AxArtifactKey> updatedTasks,
-        AxState state, AxArtifactKey taskKey, AxStateTaskReference taskRef, AxTask task) {
+                                              AxState state, AxArtifactKey taskKey, AxStateTaskReference taskRef,
+                                              AxTask task) {
         Map<String, AxEvent> outputEvents = new TreeMap<>();
         AxStateOutput stateOutput = null;
         if (AxStateTaskOutputType.LOGIC.equals(taskRef.getStateTaskOutputType())) {
@@ -279,14 +280,13 @@ public class ApexEngineImpl implements ApexEngine {
         }
         // Stop the engine if it is in state READY, if it is in state EXECUTING, wait for execution to finish
         for (int increment = ApexEngineConstants.STOP_EXECUTION_WAIT_TIMEOUT; increment > 0;
-            increment -= ApexEngineConstants.APEX_ENGINE_STOP_EXECUTION_WAIT_INCREMENT) {
+             increment -= ApexEngineConstants.APEX_ENGINE_STOP_EXECUTION_WAIT_INCREMENT) {
             ThreadUtilities.sleep(ApexEngineConstants.APEX_ENGINE_STOP_EXECUTION_WAIT_INCREMENT);
 
             synchronized (stateLockObj) {
                 switch (state) {
                     // Engine is OK to stop or has been stopped on return of an event
-                    case READY:
-                    case STOPPED:
+                    case READY, STOPPED:
                         state = AxEngineState.STOPPED;
                         updateStatePrometheusMetric();
                         stateMachineHandler.stop();
@@ -388,7 +388,7 @@ public class ApexEngineImpl implements ApexEngine {
         String message = "execute(): triggered by event " + incomingEvent.toString();
         LOGGER.debug(message);
 
-        // By default we return a null event on errors
+        // By default, we return a null event on errors
         Collection<EnEvent> outgoingEvents = null;
         try {
             engineStats.executionEnter(incomingEvent.getKey());
@@ -406,7 +406,7 @@ public class ApexEngineImpl implements ApexEngine {
         try {
             synchronized (eventListeners) {
                 if (eventListeners.isEmpty()) {
-                    LOGGER.debug("handleEvent()<-{},{}, There is no listener registered to recieve outgoing event: {}",
+                    LOGGER.debug("handleEvent()<-{},{}, There is no listener registered to receive outgoing event: {}",
                         key.getId(), state, outgoingEvents);
                 }
                 for (final EnEventListener axEventListener : eventListeners.values()) {
diff --git a/core/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java b/core/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java
index 6cbc04678..6b8dd43ec 100644
--- a/core/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java
+++ b/core/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019 Nordix Foundation.
+ *  Modifications Copyright (C) 2019, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
@@ -129,7 +129,7 @@ public class StateMachineExecutor implements Executor<EnEvent, Collection<EnEven
     public Collection<EnEvent> execute(final long executionId, final Properties executionProperties,
         final EnEvent incomingEvent) throws StateMachineException, ContextException {
         // Check if there are any states on the state machine
-        if (stateExecutorMap.size() == 0) {
+        if (stateExecutorMap.isEmpty()) {
             throw new StateMachineException("no states defined on state machine");
         }
 
diff --git a/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContext.java b/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContext.java
index 12e350390..7cdca18d8 100644
--- a/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContext.java
+++ b/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContext.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020-2021 Nordix Foundation.
+ *  Modifications Copyright (C) 2020-2021, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
@@ -86,7 +86,7 @@ public class StateFinalizerExecutionContext extends AbstractExecutionContext {
     /**
      * Logger for state finalizer execution, state finalizer logic can use this field to access and log to Apex logging.
      */
-    public final XLogger logger = EXCEUTION_LOGGER;
+    public static final XLogger logger = EXCEUTION_LOGGER;
 
     // CHECKSTYLE:ON: checkstyle:visibilityModifier
 
diff --git a/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContext.java b/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContext.java
index a54252e05..d5bb370bc 100644
--- a/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContext.java
+++ b/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContext.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
@@ -83,7 +83,7 @@ public class TaskExecutionContext extends AbstractExecutionContext {
     /**
      * Logger for task execution, task logic can use this field to access and log to Apex logging.
      */
-    public final XLogger logger = EXECUTION_LOGGER;
+    public static final XLogger logger = EXECUTION_LOGGER;
 
     // CHECKSTYLE:ON: checkstyle:VisibilityModifier
 
diff --git a/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java b/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java
index c79e907d9..62808dfb6 100644
--- a/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java
+++ b/core/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
@@ -73,7 +73,7 @@ public class TaskSelectionExecutionContext extends AbstractExecutionContext {
     /**
      * Logger for task selection execution, task selection logic can use this field to access and log to Apex logging.
      */
-    public final XLogger logger = EXECUTION_LOGGER;
+    public static final XLogger logger = EXECUTION_LOGGER;
 
     // CHECKSTYLE:ON: checkstyle:VisibilityModifier
 
diff --git a/core/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java b/core/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java
index 9dc841f48..53b041e36 100644
--- a/core/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java
+++ b/core/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2019-2020, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -157,21 +157,21 @@ public class ExecutorFactoryImpl implements ExecutorFactory {
         }
 
         // Get the class for the executor using reflection
-        Class<? extends Object> executorPluginClass = null;
+        Class<?> executorPluginClass;
         try {
             executorPluginClass = Class.forName(executorClassName);
         } catch (final ClassNotFoundException e) {
-            LOGGER.error("Apex executor class not found for executor plugin \"" + executorClassName + "\"", e);
+            LOGGER.error("Apex executor class not found for executor plugin \"{}\"", executorClassName, e);
             throw new StateMachineException(
                     "Apex executor class not found for executor plugin \"" + executorClassName + "\"", e);
         }
 
         // Check the class is an executor
         if (!Executor.class.isAssignableFrom(executorPluginClass)) {
-            LOGGER.error("Specified Apex executor plugin class \"{}\" does not implment the Executor interface",
+            LOGGER.error("Specified Apex executor plugin class \"{}\" does not implement the Executor interface",
                     executorClassName);
             throw new StateMachineException("Specified Apex executor plugin class \"" + executorClassName
-                    + "\" does not implment the Executor interface");
+                    + "\" does not implement the Executor interface");
         }
 
         return (Class<Executor<?, ?, ?, ?>>) executorPluginClass;
@@ -181,14 +181,14 @@ public class ExecutorFactoryImpl implements ExecutorFactory {
      * Get an instance of an executor plugin class of the specified type and super type.
      *
      * @param logicFlavour The logic flavour of the logic
-     * @param executorClass The sub-class of the executor type to be instantiated
+     * @param executorClass The subclass of the executor type to be instantiated
      * @param executorSuperClass The super type of the class of executor to be instantiated
      * @return The instantiated class
      */
     private Executor<?, ?, ?, ?> createExecutor(final String logicFlavour,
             final Class<Executor<?, ?, ?, ?>> executorClass,
             final Class<? extends Executor<?, ?, ?, ?>> executorSuperClass) {
-        // It's OK for an executor class not to be defined but it's not all right to try and create
+        // It's OK for an executor class not to be defined, but it's not all right to try and create
         // a non-defined
         // executor class
         if (executorClass == null) {
@@ -199,7 +199,7 @@ public class ExecutorFactoryImpl implements ExecutorFactory {
         }
 
         // Create an executor for the specified logic flavour
-        Object executorObject = null;
+        Executor<?, ?, ?, ?> executorObject;
         try {
             executorObject = executorClass.getDeclaredConstructor().newInstance();
         } catch (final Exception e) {
@@ -218,6 +218,6 @@ public class ExecutorFactoryImpl implements ExecutorFactory {
             throw new StateMachineRuntimeException(errorMessage);
         }
 
-        return (Executor<?, ?, ?, ?>) executorObject;
+        return executorObject;
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/EngineParametersTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/EngineParametersTest.java
index 5427c3515..33c9b3efb 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/EngineParametersTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/EngineParametersTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,26 +23,25 @@
 package org.onap.policy.apex.core.engine;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 import org.onap.policy.apex.context.parameters.ContextParameters;
 import org.onap.policy.common.parameters.ParameterService;
 
 /**
  * Test the executor parameters.
- *
  */
-public class EngineParametersTest {
+class EngineParametersTest {
 
     @Test
-    public void test() {
+    void test() {
         EngineParameters pars = new EngineParameters();
         pars.setName("Name");
         assertEquals("Name", pars.getName());
@@ -70,7 +69,7 @@ public class EngineParametersTest {
     }
 
     @Test
-    public void test_invalid() {
+    void test_invalid() {
         EngineParameters pars = new EngineParameters();
         pars.setName("Name");
         assertEquals("Name", pars.getName());
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/ExecutorParametersTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/ExecutorParametersTest.java
index 784580422..5e1ee81fd 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/ExecutorParametersTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/ExecutorParametersTest.java
@@ -1,7 +1,8 @@
 /*-
  * ============LICENSE_START=======================================================
- *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2018 Ericsson. All rights reserved.
+ * Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * Modifications Copyright (C) 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,20 +23,19 @@
 package org.onap.policy.apex.core.engine;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 import org.onap.policy.common.parameters.ParameterService;
 
 /**
  * Test the executor parameters.
- *
  */
-public class ExecutorParametersTest {
+class ExecutorParametersTest {
 
     @Test
-    public void test() {
+    void test() {
         ExecutorParameters pars = new ExecutorParameters();
         pars.setName("Name");
         assertEquals("Name", pars.getName());
@@ -47,8 +47,8 @@ public class ExecutorParametersTest {
         assertEquals("some.task.selection.executor.plugin.class", pars.getTaskSelectionExecutorPluginClass());
 
         assertEquals("ExecutorParameters [name=Name, taskExecutorPluginClass=some.task.executor.plugin.class, "
-                        + "taskSelectionExecutorPluginClass=some.task.selection.executor.plugin.class, "
-                        + "stateFinalizerExecutorPluginClass=some.state.finalizer.plugin.class]", pars.toString());
+            + "taskSelectionExecutorPluginClass=some.task.selection.executor.plugin.class, "
+            + "stateFinalizerExecutorPluginClass=some.state.finalizer.plugin.class]", pars.toString());
 
         assertThat(pars.validate().getResult()).isNull();
         assertTrue(pars.validate().isValid());
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java
index 19828f6e2..e918deb12 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2019-2020, 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,11 +22,11 @@
 package org.onap.policy.apex.core.engine.context;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.onap.policy.apex.context.ContextException;
 import org.onap.policy.apex.context.parameters.ContextParameterConstants;
 import org.onap.policy.apex.context.parameters.DistributorParameters;
@@ -42,20 +42,19 @@ import org.onap.policy.common.parameters.ParameterService;
 /**
  * Test the Apex engine internal context class.
  */
-public class ApexInternalContextTest {
+class ApexInternalContextTest {
 
     private AxPolicyModel policyModel;
     private AxPolicyModel newVersionPolicyModel;
     private AxPolicyModel newPolicyModel;
     private AxContextAlbum album;
-    private AxContextAlbum newAlbum;
     private AxPolicyModel incompatiblePolicyModel;
 
     /**
      * Initialize parameters.
      */
-    @Before
-    public void registerParameters() {
+    @BeforeEach
+    void registerParameters() {
         ParameterService.register(new SchemaParameters());
         ParameterService.register(new DistributorParameters());
         ParameterService.register(new LockManagerParameters());
@@ -65,8 +64,8 @@ public class ApexInternalContextTest {
     /**
      * Create policy model.
      */
-    @Before
-    public void createPolicyModels() {
+    @BeforeEach
+    void createPolicyModels() {
         AxArtifactKey modelKey = new AxArtifactKey("PolicyModel:0.0.1");
         policyModel = new AxPolicyModel(modelKey);
 
@@ -109,7 +108,7 @@ public class ApexInternalContextTest {
         newPolicyModel.getSchemas().getSchemasMap().put(newSchemaKey, newSchema);
 
         AxArtifactKey newAlbumKey = new AxArtifactKey("NewAlbum:0.0.1");
-        newAlbum = new AxContextAlbum(newAlbumKey, "Policy", true, newSchemaKey);
+        AxContextAlbum newAlbum = new AxContextAlbum(newAlbumKey, "Policy", true, newSchemaKey);
 
         newPolicyModel.getAlbums().getAlbumsMap().put(newAlbumKey, newAlbum);
     }
@@ -117,8 +116,8 @@ public class ApexInternalContextTest {
     /**
      * Deregister parameters.
      */
-    @After
-    public void deregisterParameters() {
+    @AfterEach
+    void deregisterParameters() {
         ParameterService.deregister(ContextParameterConstants.DISTRIBUTOR_GROUP_NAME);
         ParameterService.deregister(ContextParameterConstants.LOCKING_GROUP_NAME);
         ParameterService.deregister(ContextParameterConstants.PERSISTENCE_GROUP_NAME);
@@ -126,7 +125,7 @@ public class ApexInternalContextTest {
     }
 
     @Test
-    public void testAlbumInit() throws ContextException {
+    void testAlbumInit() throws ContextException {
         assertThatThrownBy(() -> new ApexInternalContext(null))
             .hasMessage("internal context update failed, supplied model is null");
         ApexInternalContext context = new ApexInternalContext(policyModel);
@@ -140,17 +139,17 @@ public class ApexInternalContextTest {
         assertEquals(album.getId(), context.get(albumKey.getName(), albumKey.getVersion()).getKey().getId());
         assertEquals(album.getId(), context.getAll(albumKey.getName()).iterator().next().getKey().getId());
         assertEquals(album.getId(),
-                        context.getAll(albumKey.getName(), albumKey.getVersion()).iterator().next().getKey().getId());
+            context.getAll(albumKey.getName(), albumKey.getVersion()).iterator().next().getKey().getId());
 
         context.clear();
         assertEquals(1, context.getContextAlbums().size());
 
         assertEquals("ApexInternalContext [contextAlbums={AxArtifactKey:(name=Album,version=0.0.1)",
-                        context.toString().substring(0, 76));
+            context.toString().substring(0, 76));
     }
 
     @Test
-    public void testAlbumUpdate() throws ContextException {
+    void testAlbumUpdate() throws ContextException {
         ApexInternalContext context = new ApexInternalContext(policyModel);
         assertThatThrownBy(() -> context.update(null, false))
             .hasMessage("internal context update failed, supplied model is null");
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImplTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImplTest.java
index 8d7df45cd..a66f8c683 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImplTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImplTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019-2021, 2023 Nordix Foundation.
+ *  Modifications Copyright (C) 2019-2021, 2023-2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -24,25 +24,25 @@ package org.onap.policy.apex.core.engine.engine.impl;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.awaitility.Awaitility.await;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import io.prometheus.client.CollectorRegistry;
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.util.HashMap;
 import java.util.concurrent.TimeUnit;
-import org.junit.AfterClass;
-import org.junit.Before;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.parameters.ContextParameterConstants;
 import org.onap.policy.apex.context.parameters.DistributorParameters;
 import org.onap.policy.apex.context.parameters.LockManagerParameters;
@@ -71,8 +71,8 @@ import org.onap.policy.common.parameters.ParameterService;
 /**
  * Test the engine implementation.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class ApexEngineImplTest {
+@ExtendWith(MockitoExtension.class)
+class ApexEngineImplTest {
     private static final String ENGINE_ID = "Engine:0.0.1";
 
     private AxPolicyModel policyModel;
@@ -85,8 +85,8 @@ public class ApexEngineImplTest {
     /**
      * Set up services.
      */
-    @BeforeClass
-    public static void setup() {
+    @BeforeAll
+    static void setup() {
         ParameterService.register(new SchemaParameters());
         ParameterService.register(new DistributorParameters());
         ParameterService.register(new LockManagerParameters());
@@ -97,17 +97,17 @@ public class ApexEngineImplTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void initializeMocking() throws ApexException {
-        Mockito.doThrow(new StateMachineException("mocked state machine exception",
-                        new IOException("nexted exception"))).when(smHandlerMock).execute(Mockito.any());
+    @BeforeEach
+    void initializeMocking() throws ApexException {
+        Mockito.lenient().doThrow(new StateMachineException("mocked state machine exception",
+            new IOException("nexted exception"))).when(smHandlerMock).execute(Mockito.any());
     }
 
     /**
      * Create policy models.
      */
-    @Before
-    public void createPolicyModels() {
+    @BeforeEach
+    void createPolicyModels() {
         AxArtifactKey modelKey = new AxArtifactKey("PolicyModel:0.0.1");
         policyModel = new AxPolicyModel(modelKey);
 
@@ -162,8 +162,8 @@ public class ApexEngineImplTest {
     /**
      * Clear registrations.
      */
-    @AfterClass
-    public static void teardown() {
+    @AfterAll
+    static void teardown() {
         ParameterService.deregister(ContextParameterConstants.SCHEMA_GROUP_NAME);
         ParameterService.deregister(ContextParameterConstants.DISTRIBUTOR_GROUP_NAME);
         ParameterService.deregister(ContextParameterConstants.LOCKING_GROUP_NAME);
@@ -172,14 +172,14 @@ public class ApexEngineImplTest {
     }
 
     @Test
-    public void testSanity() throws ApexException  {
+    void testSanity() throws ApexException {
         AxArtifactKey engineKey = new AxArtifactKey(ENGINE_ID);
         ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
         assertNotNull(engine);
         assertEquals(engineKey, engine.getKey());
 
         assertThatThrownBy(engine::start).hasMessage("start()<-Engine:0.0.1,STOPPED,  cannot start engine, "
-                            + "engine has not been initialized, its model is not loaded");
+            + "engine has not been initialized, its model is not loaded");
 
         assertThatThrownBy(engine::stop)
             .hasMessage("stop()<-Engine:0.0.1,STOPPED, cannot stop engine, " + "engine is already stopped");
@@ -203,7 +203,7 @@ public class ApexEngineImplTest {
     }
 
     @Test
-    public void testListener() throws ApexException {
+    void testListener() throws ApexException {
         AxArtifactKey engineKey = new AxArtifactKey(ENGINE_ID);
         ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
 
@@ -262,7 +262,7 @@ public class ApexEngineImplTest {
     }
 
     @Test
-    public void testEventKey() throws ApexException {
+    void testEventKey() throws ApexException {
         AxArtifactKey engineKey = new AxArtifactKey(ENGINE_ID);
         ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
         engine.updateModel(policyModel, false);
@@ -315,7 +315,7 @@ public class ApexEngineImplTest {
     }
 
     @Test
-    public void testState() throws InterruptedException, ApexException {
+    void testState() throws ApexException {
         AxArtifactKey engineKey = new AxArtifactKey(ENGINE_ID);
         ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
         assertNotNull(engine);
@@ -332,21 +332,13 @@ public class ApexEngineImplTest {
         assertEquals(AxEngineState.READY, engine.getState());
         checkAxEngineStateMetric(AxEngineState.READY);
 
-        assertEquals(AxEngineState.READY, engine.getState());
-        checkAxEngineStateMetric(AxEngineState.READY);
-
         AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
         EnEvent event = engine.createEvent(eventKey);
         assertEquals(eventKey, event.getKey());
 
-        // 1 second is less than the 3 second wait on engine stopping
+        // 1 second is less than the 3 seconds wait on engine stopping
         slowListener.setWaitTime(1000);
-        (new Thread() {
-            @Override
-            public void run() {
-                engine.handleEvent(event);
-            }
-        }).start();
+        (new Thread(() -> engine.handleEvent(event))).start();
         await().atLeast(50, TimeUnit.MILLISECONDS).until(() -> engine.getState().equals(AxEngineState.EXECUTING));
         assertEquals(AxEngineState.EXECUTING, engine.getState());
         checkAxEngineStateMetric(AxEngineState.EXECUTING);
@@ -362,14 +354,9 @@ public class ApexEngineImplTest {
         assertEquals(AxEngineState.READY, engine.getState());
         checkAxEngineStateMetric(AxEngineState.READY);
 
-        // 4 seconds is more than the 3 second wait on engine stopping
+        // 4 seconds is more than the 3 seconds wait on engine stopping
         slowListener.setWaitTime(4000);
-        (new Thread() {
-            @Override
-            public void run() {
-                engine.handleEvent(event);
-            }
-        }).start();
+        (new Thread(() -> engine.handleEvent(event))).start();
 
         await().atLeast(50, TimeUnit.MILLISECONDS).until(() -> engine.getState().equals(AxEngineState.EXECUTING));
         assertEquals(AxEngineState.EXECUTING, engine.getState());
@@ -384,8 +371,8 @@ public class ApexEngineImplTest {
     }
 
     @Test
-    public void testStateMachineError() throws InterruptedException, IllegalArgumentException, IllegalAccessException,
-                    NoSuchFieldException, SecurityException, ApexException {
+    void testStateMachineError() throws IllegalArgumentException, IllegalAccessException,
+        NoSuchFieldException, SecurityException, ApexException {
 
         AxArtifactKey engineKey = new AxArtifactKey(ENGINE_ID);
         ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
@@ -404,9 +391,6 @@ public class ApexEngineImplTest {
         assertEquals(AxEngineState.READY, engine.getState());
         checkAxEngineStateMetric(AxEngineState.READY);
 
-        assertEquals(AxEngineState.READY, engine.getState());
-        checkAxEngineStateMetric(AxEngineState.READY);
-
         AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
         EnEvent event = engine.createEvent(eventKey);
         assertEquals(eventKey, event.getKey());
@@ -419,9 +403,9 @@ public class ApexEngineImplTest {
         assertEquals(AxEngineState.STOPPED, engine.getState());
         checkAxEngineStateMetric(AxEngineState.STOPPED);
         Mockito.doThrow(new StateMachineException("mocked state machine exception",
-                new IOException("nexted exception"))).when(smHandlerMock).start();
+            new IOException("nexted exception"))).when(smHandlerMock).start();
         assertThatThrownBy(engine::start).hasMessage("updateModel()<-Engine:0.0.1, error starting the engine state "
-                + "machines \"Engine:0.0.1\"");
+            + "machines \"Engine:0.0.1\"");
         assertEquals(AxEngineState.STOPPED, engine.getState());
         checkAxEngineStateMetric(AxEngineState.STOPPED);
 
@@ -431,8 +415,8 @@ public class ApexEngineImplTest {
     }
 
     @Test
-    public void testStateMachineHandler() throws InterruptedException, IllegalArgumentException, IllegalAccessException,
-                    NoSuchFieldException, SecurityException, ApexException {
+    void testStateMachineHandler() throws IllegalArgumentException, IllegalAccessException,
+        NoSuchFieldException, SecurityException, ApexException {
         AxArtifactKey engineKey = new AxArtifactKey(ENGINE_ID);
         ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
         assertNotNull(engine);
@@ -450,10 +434,24 @@ public class ApexEngineImplTest {
         EnEvent event = engine.createEvent(eventKey);
         assertEquals(eventKey, event.getKey());
 
+        assertEngineStopStartState(engine, event);
+
+        HashMap<AxEvent, StateMachineExecutor>
+            smExMap = getAxEventStateMachineExecutorHashMap(engine);
+
+        assertEquals(1, smExMap.size());
+        DummySmExecutor dummyExecutor = new DummySmExecutor(null, event.getKey());
+        smExMap.put(event.getAxEvent(), dummyExecutor);
+        ApexInternalContext internalContext = new ApexInternalContext(policyModelWithStates);
+        assertThatThrownBy(() -> dummyExecutor.setContext(null, null, internalContext))
+            .isInstanceOf(NullPointerException.class);
+
         engine.stop();
         assertEquals(AxEngineState.STOPPED, engine.getState());
         checkAxEngineStateMetric(AxEngineState.STOPPED);
 
+        assertThatThrownBy(engine::start).hasMessageContaining("updateModel()<-Engine:0.0.1, error starting the "
+            + "engine state machines \"Engine:0.0.1\"");
         assertEquals(AxEngineState.STOPPED, engine.getState());
         checkAxEngineStateMetric(AxEngineState.STOPPED);
 
@@ -461,14 +459,22 @@ public class ApexEngineImplTest {
         assertEquals(AxEngineState.READY, engine.getState());
         checkAxEngineStateMetric(AxEngineState.READY);
 
+        // Works, Dummy executor fakes event execution
+        assertTrue(engine.handleEvent(event));
         assertEquals(AxEngineState.READY, engine.getState());
         checkAxEngineStateMetric(AxEngineState.READY);
 
-        // Can't work, state is not fully defined
-        assertFalse(engine.handleEvent(event));
-        assertEquals(AxEngineState.READY, engine.getState());
-        checkAxEngineStateMetric(AxEngineState.READY);
+        engine.stop();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+        checkAxEngineStateMetric(AxEngineState.STOPPED);
+
+        engine.clear();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+        checkAxEngineStateMetric(AxEngineState.STOPPED);
+    }
 
+    private static HashMap<AxEvent, StateMachineExecutor> getAxEventStateMachineExecutorHashMap(ApexEngineImpl engine)
+        throws NoSuchFieldException, IllegalAccessException {
         final Field smHandlerField = engine.getClass().getDeclaredField("stateMachineHandler");
         smHandlerField.setAccessible(true);
         StateMachineHandler smHandler = (StateMachineHandler) smHandlerField.get(engine);
@@ -477,45 +483,28 @@ public class ApexEngineImplTest {
         smExecutorMapField.setAccessible(true);
         @SuppressWarnings("unchecked")
         HashMap<AxEvent, StateMachineExecutor> smExMap = (HashMap<AxEvent, StateMachineExecutor>) smExecutorMapField
-                        .get(smHandler);
-
-        assertEquals(1, smExMap.size());
-        DummySmExecutor dummyExecutor = new DummySmExecutor(null, event.getKey());
-        smExMap.put(event.getAxEvent(), dummyExecutor);
-        ApexInternalContext internalContext = new ApexInternalContext(policyModelWithStates);
-        assertThatThrownBy(() -> dummyExecutor.setContext(null, null, internalContext))
-            .isInstanceOf(NullPointerException.class);
+            .get(smHandler);
+        return smExMap;
+    }
 
+    private void assertEngineStopStartState(ApexEngineImpl engine, EnEvent event) throws ApexException {
         engine.stop();
         assertEquals(AxEngineState.STOPPED, engine.getState());
         checkAxEngineStateMetric(AxEngineState.STOPPED);
 
-        assertThatThrownBy(engine::start).hasMessageContaining("updateModel()<-Engine:0.0.1, error starting the "
-                    + "engine state machines \"Engine:0.0.1\"");
-        assertEquals(AxEngineState.STOPPED, engine.getState());
-        checkAxEngineStateMetric(AxEngineState.STOPPED);
-
         engine.start();
         assertEquals(AxEngineState.READY, engine.getState());
         checkAxEngineStateMetric(AxEngineState.READY);
 
-        // Works, Dummy executor fakes event execution
-        assertTrue(engine.handleEvent(event));
+        // Can't work, state is not fully defined
+        assertFalse(engine.handleEvent(event));
         assertEquals(AxEngineState.READY, engine.getState());
         checkAxEngineStateMetric(AxEngineState.READY);
-
-        engine.stop();
-        assertEquals(AxEngineState.STOPPED, engine.getState());
-        checkAxEngineStateMetric(AxEngineState.STOPPED);
-
-        engine.clear();
-        assertEquals(AxEngineState.STOPPED, engine.getState());
-        checkAxEngineStateMetric(AxEngineState.STOPPED);
     }
 
     private void checkAxEngineStateMetric(AxEngineState state) {
         Double stateMetric = CollectorRegistry.defaultRegistry
-            .getSampleValue("pdpa_engine_state", new String[]{"engine_instance_id"}, new String[]{ENGINE_ID});
+            .getSampleValue("pdpa_engine_state", new String[] {"engine_instance_id"}, new String[] {ENGINE_ID});
         assertEquals(stateMetric.intValue(), state.getStateIdentifier());
     }
 }
\ No newline at end of file
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyEnEventListener.java b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyEnEventListener.java
index b429295ad..2227379a6 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyEnEventListener.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyEnEventListener.java
@@ -5,15 +5,15 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
@@ -26,7 +26,6 @@ import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
 
 /**
  * Dummy engine event listener for unit test.
- *
  */
 public class DummyEnEventListener implements EnEventListener {
 
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyListener.java b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyListener.java
index 6256ff498..565bb2348 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyListener.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyListener.java
@@ -1,19 +1,20 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * Modifications Copyright (C) 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
@@ -26,7 +27,6 @@ import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
 
 /**
  * Dummy engine event listener for unit test.
- *
  */
 public class DummyListener implements EnEventListener {
 
@@ -34,7 +34,7 @@ public class DummyListener implements EnEventListener {
      * {@inheritDoc}.
      */
     @Override
-    public void onEnEvent(EnEvent enEvent) throws ApexException {
+    public void onEnEvent(EnEvent enEvent) {
         // Do nothing
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySlowEnEventListener.java b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySlowEnEventListener.java
index e794a7d04..fdc698145 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySlowEnEventListener.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySlowEnEventListener.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019-2021 Nordix Foundation.
+ *  Modifications Copyright (C) 2019-2021, 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,15 +21,17 @@
 
 package org.onap.policy.apex.core.engine.engine.impl;
 
+import lombok.Getter;
+import lombok.Setter;
 import org.onap.policy.apex.core.engine.engine.EnEventListener;
 import org.onap.policy.apex.core.engine.event.EnEvent;
-import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
 
 /**
  * Dummy engine event listener for unit test.
  * Thread.sleep is used to simulate a slow event listener.
- *
  */
+@Setter
+@Getter
 public class DummySlowEnEventListener implements EnEventListener {
 
     private long waitTime;
@@ -38,19 +40,11 @@ public class DummySlowEnEventListener implements EnEventListener {
      * {@inheritDoc}.
      */
     @Override
-    public void onEnEvent(EnEvent enEvent) throws ApexException {
+    public void onEnEvent(EnEvent enEvent) {
         try {
             Thread.sleep(waitTime);
         } catch (InterruptedException ie) {
             //Do nothing
         }
     }
-
-    public long getWaitTime() {
-        return waitTime;
-    }
-
-    public void setWaitTime(long waitTime) {
-        this.waitTime = waitTime;
-    }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySmExecutor.java b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySmExecutor.java
index df4d9279e..719a20e82 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySmExecutor.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySmExecutor.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019 Nordix Foundation.
+ *  Modifications Copyright (C) 2019, 2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -42,7 +42,7 @@ public class DummySmExecutor extends StateMachineExecutor {
      * Constructor.
      *
      * @param executorFactory the factory for executors
-     * @param owner the owner key
+     * @param owner           the owner key
      */
     public DummySmExecutor(ExecutorFactory executorFactory, AxArtifactKey owner) {
         super(executorFactory, owner);
@@ -66,7 +66,7 @@ public class DummySmExecutor extends StateMachineExecutor {
      */
     @Override
     public Collection<EnEvent> execute(final long executionId, final Properties executionProperties,
-        final EnEvent incomingEvent) {
+                                       final EnEvent incomingEvent) {
         return List.of(incomingEvent);
     }
 
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/event/DummyAxKey.java b/core/src/test/java/org/onap/policy/apex/core/engine/event/DummyAxKey.java
index eafa7f419..a806bed37 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/event/DummyAxKey.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/event/DummyAxKey.java
@@ -1,25 +1,27 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * Modifications Copyright (C) 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
 
 package org.onap.policy.apex.core.engine.event;
 
+import java.io.Serial;
 import java.util.List;
 import org.apache.commons.lang3.NotImplementedException;
 import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
@@ -30,6 +32,8 @@ import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
  * Dummy Key Class.
  */
 public class DummyAxKey extends AxKey {
+
+    @Serial
     private static final long serialVersionUID = 964899169013353800L;
 
     /**
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java
index 49b4f80d2..18a7070bf 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020-2021 Nordix Foundation
+ *  Modifications Copyright (C) 2020-2021, 2024 Nordix Foundation
  *  Modifications Copyright (C) 2022 Bell Canada. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,18 +23,18 @@
 package org.onap.policy.apex.core.engine.event;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.onap.policy.apex.context.parameters.ContextParameterConstants;
 import org.onap.policy.apex.context.parameters.SchemaParameters;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
@@ -51,12 +51,12 @@ import org.onap.policy.common.parameters.ParameterService;
 /**
  * Test the engine event class.
  */
-public class EnEventTest {
+class EnEventTest {
     /**
      * Set up the services.
      */
-    @Before
-    public void setupServices() {
+    @BeforeEach
+    void setupServices() {
         ModelService.registerModel(AxContextSchemas.class, new AxContextSchemas());
         ModelService.registerModel(AxEvents.class, new AxEvents());
         ParameterService.register(new SchemaParameters());
@@ -65,15 +65,15 @@ public class EnEventTest {
     /**
      * Tear down the services.
      */
-    @After
-    public void teardownServices() {
+    @AfterEach
+    void teardownServices() {
         ModelService.deregisterModel(AxContextSchema.class);
         ModelService.deregisterModel(AxEvents.class);
         ParameterService.deregister(ContextParameterConstants.SCHEMA_GROUP_NAME);
     }
 
     @Test
-    public void testEnEvent() {
+    void testEnEvent() {
         AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
         assertThatThrownBy(() -> new EnEvent(eventKey))
             .hasMessage("event definition is null or was not found in model service");
@@ -92,12 +92,12 @@ public class EnEventTest {
         event.setExceptionMessage("Something happened");
         assertEquals("Something happened", event.getExceptionMessage());
         AxConcept[] usedArtifactStackArray =
-            { eventKey };
+            {eventKey};
         event.setUserArtifactStack(usedArtifactStackArray);
         assertEquals(usedArtifactStackArray.length, event.getUserArtifactStack().length);
         assertEquals("EnEvent [axEvent=AxEvent:(key=AxArtifactKey:(name=Event,version=0.0.1),nameSpace=a.name.space,"
-                        + "source=some source,target=some target,parameter={},toscaPolicyState=), "
-                        + "userArtifactStack=[AxArtifactKey:(name=Event,version=0.0.1)], map={}]", event.toString());
+            + "source=some source,target=some target,parameter={},toscaPolicyState=), "
+            + "userArtifactStack=[AxArtifactKey:(name=Event,version=0.0.1)], map={}]", event.toString());
         assertThatThrownBy(() -> event.put(null, null))
             .hasMessage("null keys are illegal on method parameter \"key\"");
         assertThatThrownBy(() -> event.put("NonField", null))
@@ -105,7 +105,7 @@ public class EnEventTest {
     }
 
     @Test
-    public void testAxEvent() {
+    void testAxEvent() {
         AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
         AxEvent axEvent = new AxEvent(eventKey, "a.name.space", "some source", "some target");
         ModelService.getModel(AxEvents.class).getEventMap().put(eventKey, axEvent);
@@ -116,7 +116,7 @@ public class EnEventTest {
         AxField axField = new AxField(fieldKey, fieldSchemaKey);
 
         AxConcept[] usedArtifactStackArrayMultiple =
-            { eventKey, fieldKey, new DummyAxKey() };
+            {eventKey, fieldKey, new DummyAxKey()};
         event.setUserArtifactStack(usedArtifactStackArrayMultiple);
 
         AxContextSchema schema = new AxContextSchema(fieldSchemaKey, "Java", "java.lang.Integer");
@@ -131,12 +131,12 @@ public class EnEventTest {
 
         assertThatThrownBy(() -> event.put("MyField", "Hello"))
             .hasMessage("Parent:0.0.1:MyParent:MyField: object \"Hello\" of class \"java.lang.String\" "
-                            + "not compatible with class \"java.lang.Integer\"");
+                + "not compatible with class \"java.lang.Integer\"");
         event.put("MyField", 123);
         assertEquals(123, event.get("MyField"));
 
-        assertTrue(event.keySet().contains("MyField"));
-        assertTrue(event.values().contains(123));
+        assertTrue(event.containsKey("MyField"));
+        assertTrue(event.containsValue(123));
         assertEquals("MyField", event.entrySet().iterator().next().getKey());
 
         event.putAll(event);
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/event/EnExceptionTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/event/EnExceptionTest.java
index 5ca49e479..554de6bfd 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/event/EnExceptionTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/event/EnExceptionTest.java
@@ -1,37 +1,38 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * Modifications Copyright (C) 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
 
 package org.onap.policy.apex.core.engine.event;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import java.io.IOException;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 /**
  * Test the event exception class.
  */
-public class EnExceptionTest {
+class EnExceptionTest {
 
     @Test
-    public void testEnException() {
+    void testEnException() {
         EnException ene = new EnException("Message");
         assertEquals("Message", ene.getMessage());
 
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java
index dbe2fa3c8..d88f79b58 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020 Nordix Foundation
+ *  Modifications Copyright (C) 2020, 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,13 +22,13 @@
 package org.onap.policy.apex.core.engine.event;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.onap.policy.apex.context.parameters.ContextParameterConstants;
 import org.onap.policy.apex.context.parameters.SchemaParameters;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
@@ -42,12 +42,12 @@ import org.onap.policy.common.parameters.ParameterService;
 /**
  * Test the EnField class.
  */
-public class EnFieldTest {
+class EnFieldTest {
     /**
      * Set up the services.
      */
-    @Before
-    public void setupServices() {
+    @BeforeEach
+    void setupServices() {
         AxContextSchemas schemas = new AxContextSchemas();
         ModelService.registerModel(AxContextSchemas.class, schemas);
         ParameterService.register(new SchemaParameters());
@@ -56,14 +56,14 @@ public class EnFieldTest {
     /**
      * Tear down the services.
      */
-    @After
-    public void teardownServices() {
+    @AfterEach
+    void teardownServices() {
         ModelService.deregisterModel(AxContextSchemas.class);
         ParameterService.deregister(ContextParameterConstants.SCHEMA_GROUP_NAME);
     }
 
     @Test
-    public void testEnField() {
+    void testEnField() {
         AxReferenceKey fieldKey = new AxReferenceKey("Parent", "0.0.1", "MyParent", "MyField");
         AxArtifactKey fieldSchemaKey = new AxArtifactKey("FieldSchema:0.0.1");
         AxField axField = new AxField(fieldKey, fieldSchemaKey);
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyFailingTaskExecutor.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyFailingTaskExecutor.java
index 4d4fb639f..02fa41bc8 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyFailingTaskExecutor.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyFailingTaskExecutor.java
@@ -5,15 +5,15 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyStateFinalizerExecutor.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyStateFinalizerExecutor.java
index e4e3ddf0d..a7b2a43d4 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyStateFinalizerExecutor.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyStateFinalizerExecutor.java
@@ -25,6 +25,7 @@ package org.onap.policy.apex.core.engine.executor;
 import java.util.Map;
 import java.util.Properties;
 import lombok.NoArgsConstructor;
+import lombok.Setter;
 import org.onap.policy.apex.context.ContextException;
 import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
 
@@ -35,6 +36,7 @@ import org.onap.policy.apex.core.engine.executor.exception.StateMachineException
 public class DummyStateFinalizerExecutor extends StateFinalizerExecutor {
     private boolean override;
 
+    @Setter
     private boolean returnBad;
 
     public DummyStateFinalizerExecutor(final boolean override) {
@@ -46,7 +48,7 @@ public class DummyStateFinalizerExecutor extends StateFinalizerExecutor {
      */
     @Override
     public String execute(final long executionId, final Properties executionProperties,
-            final Map<String, Object> newIncomingFields) throws StateMachineException, ContextException {
+                          final Map<String, Object> newIncomingFields) throws StateMachineException, ContextException {
 
         if (!override) {
             super.execute(executionId, executionProperties, newIncomingFields);
@@ -59,7 +61,4 @@ public class DummyStateFinalizerExecutor extends StateFinalizerExecutor {
         }
     }
 
-    public void setReturnBad(boolean returnBad) {
-        this.returnBad = returnBad;
-    }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskExecutor.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskExecutor.java
index 8172eefcc..f7306c31e 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskExecutor.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskExecutor.java
@@ -54,8 +54,9 @@ public class DummyTaskExecutor extends TaskExecutor {
      * {@inheritDoc}.
      */
     @Override
-    public  Map<String, Map<String, Object>> execute(final long executionId, final Properties executionProperties,
-            final Map<String, Object> newIncomingFields) throws StateMachineException, ContextException {
+    public Map<String, Map<String, Object>> execute(final long executionId, final Properties executionProperties,
+                                                    final Map<String, Object> newIncomingFields)
+        throws StateMachineException, ContextException {
         if (!override) {
             super.execute(executionId, executionProperties, newIncomingFields);
         }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskSelectExecutor.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskSelectExecutor.java
index a5525ac83..bfee99fe1 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskSelectExecutor.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskSelectExecutor.java
@@ -54,7 +54,7 @@ public class DummyTaskSelectExecutor extends TaskSelectExecutor {
      */
     @Override
     public AxArtifactKey execute(final long executionId, final Properties executionProperties,
-            final EnEvent newIncomingEvent) throws StateMachineException, ContextException {
+                                 final EnEvent newIncomingEvent) throws StateMachineException, ContextException {
         if (!override) {
             return super.execute(executionId, executionProperties, newIncomingEvent);
         }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateExecutorTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateExecutorTest.java
index fc1b339d2..f448514f1 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateExecutorTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateExecutorTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,14 +22,15 @@
 package org.onap.policy.apex.core.engine.executor;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.core.engine.ExecutorParameters;
 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
 import org.onap.policy.apex.core.engine.event.EnEvent;
@@ -39,8 +40,8 @@ import org.onap.policy.apex.model.policymodel.concepts.AxState;
 /**
  * Test task executor.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class StateExecutorTest {
+@ExtendWith(MockitoExtension.class)
+class StateExecutorTest {
     @Mock
     private ApexInternalContext internalContextMock;
 
@@ -56,30 +57,29 @@ public class StateExecutorTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
-
+    @BeforeEach
+    void startMocking() {
         Mockito.doReturn(new AxReferenceKey("Policy:0.0.1:PolName:State0")).when(axStateMock).getKey();
     }
 
     @Test
-    public void testStateExecutor() {
+    void testStateExecutor() {
         StateExecutor executor = new StateExecutor(executorFactoryMock);
 
         executor.setContext(null, axStateMock, internalContextMock);
         assertEquals("Policy:0.0.1:PolName:State0", executor.getKey().getId());
-        assertEquals(null, executor.getParent());
+        assertNull(executor.getParent());
         assertEquals(internalContextMock, executor.getContext());
-        assertEquals(null, executor.getNext());
-        assertEquals(null, executor.getIncoming());
-        assertEquals(null, executor.getOutgoing());
+        assertNull(executor.getNext());
+        assertNull(executor.getIncoming());
+        assertNull(executor.getOutgoing());
         assertEquals(axStateMock, executor.getSubject());
 
         executor.setParameters(new ExecutorParameters());
         executor.setNext(nextExecutorMock);
         assertEquals(nextExecutorMock, executor.getNext());
         executor.setNext(null);
-        assertEquals(null, executor.getNext());
+        assertNull(executor.getNext());
 
         assertThatThrownBy(() -> executor.executePre(0, null, null))
             .hasMessage("execution pre work not implemented on class");
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutorTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutorTest.java
index e140291b4..fff89de0d 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutorTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutorTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,16 +22,17 @@
 package org.onap.policy.apex.core.engine.executor;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 import java.util.Map;
 import java.util.Properties;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.ContextException;
 import org.onap.policy.apex.core.engine.ExecutorParameters;
 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
@@ -44,8 +45,8 @@ import org.onap.policy.apex.model.policymodel.concepts.AxStateFinalizerLogic;
 /**
  * Test task executor.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class StateFinalizerExecutorTest {
+@ExtendWith(MockitoExtension.class)
+class StateFinalizerExecutorTest {
     @Mock
     private Executor<?, ?, ?, ?> parentMock;
 
@@ -64,8 +65,8 @@ public class StateFinalizerExecutorTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
 
         AxState state = new AxState();
         state.getStateOutputs().put("ValidOutput", null);
@@ -76,24 +77,24 @@ public class StateFinalizerExecutorTest {
     }
 
     @Test
-    public void testStateFinalizerExecutor() throws StateMachineException, ContextException {
+    void testStateFinalizerExecutor() throws StateMachineException, ContextException {
         DummyStateFinalizerExecutor executor = new DummyStateFinalizerExecutor();
 
         executor.setContext(parentMock, stateFinalizerLogicMock, internalContextMock);
         assertEquals("State:0.0.1:StateName:StateSFL", executor.getKey().getId());
-        assertEquals(null, executor.getExecutionContext());
+        assertNull(executor.getExecutionContext());
         assertEquals(parentMock, executor.getParent());
         assertEquals(internalContextMock, executor.getContext());
-        assertEquals(null, executor.getNext());
-        assertEquals(null, executor.getIncoming());
-        assertEquals(null, executor.getOutgoing());
+        assertNull(executor.getNext());
+        assertNull(executor.getIncoming());
+        assertNull(executor.getOutgoing());
         assertEquals(stateFinalizerLogicMock, executor.getSubject());
 
         executor.setParameters(new ExecutorParameters());
         executor.setNext(nextExecutorMock);
         assertEquals(nextExecutorMock, executor.getNext());
         executor.setNext(null);
-        assertEquals(null, executor.getNext());
+        assertNull(executor.getNext());
 
         assertThatThrownBy(executor::cleanUp)
             .hasMessage("cleanUp() not implemented on class");
@@ -130,7 +131,7 @@ public class StateFinalizerExecutorTest {
         executor.getExecutionContext().setSelectedStateOutputName("ThisOutputDoesNotExist");
         assertThatThrownBy(() -> executor.executePost(true))
             .hasMessage("execute-post: state finalizer logic \"null\" selected output state "
-                    + "\"ThisOutputDoesNotExist\" that does not exsist on state \"NULL:0.0.0:NULL:NULL\"");
+                + "\"ThisOutputDoesNotExist\" that does not exsist on state \"NULL:0.0.0:NULL:NULL\"");
         executor.executePre(0, new Properties(), incomingEvent);
 
         executor.getExecutionContext().setSelectedStateOutputName("ValidOutput");
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutorTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutorTest.java
index 14cc89ee8..4af2f3c74 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutorTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutorTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
  * ================================================================================
@@ -24,21 +24,21 @@
 package org.onap.policy.apex.core.engine.executor;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.Collection;
 import java.util.LinkedHashMap;
 import java.util.Map;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.ContextException;
 import org.onap.policy.apex.context.parameters.SchemaParameters;
 import org.onap.policy.apex.core.engine.ExecutorParameters;
@@ -66,8 +66,8 @@ import org.onap.policy.common.parameters.ParameterService;
 /**
  * Test task executor.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class StateMachineExecutorTest {
+@ExtendWith(MockitoExtension.class)
+class StateMachineExecutorTest {
     @Mock
     private ApexInternalContext internalContextMock;
 
@@ -80,17 +80,15 @@ public class StateMachineExecutorTest {
     @Mock
     private EnEvent incomingEventMock;
 
-    private AxPolicy axPolicy = new AxPolicy();
-
-    private DummyTaskSelectExecutor dummyTsle;
+    private final AxPolicy axPolicy = new AxPolicy();
 
     private DummyStateFinalizerExecutor dummySfle;
 
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
         axPolicy.setKey(new AxArtifactKey("Policy:0.0.1"));
 
         AxReferenceKey state0Key = new AxReferenceKey(axPolicy.getKey(), "state0");
@@ -128,8 +126,8 @@ public class StateMachineExecutorTest {
         event0.getParameterMap().put("Event1Field0", event1Field0Definition);
         event0.getParameterMap().put("UnusedField", event1Field0Definition);
 
-        Mockito.doReturn(event0Key).when(incomingEventMock).getKey();
-        Mockito.doReturn(event0).when(incomingEventMock).getAxEvent();
+        Mockito.lenient().doReturn(event0Key).when(incomingEventMock).getKey();
+        Mockito.lenient().doReturn(event0).when(incomingEventMock).getAxEvent();
 
         state0.setTrigger(event0Key);
         state1.setTrigger(event1Key);
@@ -169,26 +167,26 @@ public class StateMachineExecutorTest {
         AxStateTaskReference str1 = new AxStateTaskReference(str1Key, AxStateTaskOutputType.LOGIC, sflKey);
         state1.getTaskReferences().put(task1Key, str1);
 
-        Mockito.doReturn(new DummyTaskExecutor(true)).when(executorFactoryMock).getTaskExecutor(Mockito.any(),
+        Mockito.lenient().doReturn(new DummyTaskExecutor(true)).when(executorFactoryMock).getTaskExecutor(Mockito.any(),
             Mockito.any(), Mockito.any());
 
-        dummyTsle = new DummyTaskSelectExecutor(true);
-        Mockito.doReturn(dummyTsle).when(executorFactoryMock).getTaskSelectionExecutor(Mockito.any(),
+        DummyTaskSelectExecutor dummyTsle = new DummyTaskSelectExecutor(true);
+        Mockito.lenient().doReturn(dummyTsle).when(executorFactoryMock).getTaskSelectionExecutor(Mockito.any(),
             Mockito.any(), Mockito.any());
 
         dummySfle = new DummyStateFinalizerExecutor(true);
-        Mockito.doReturn(dummySfle).when(executorFactoryMock).getStateFinalizerExecutor(Mockito.any(),
+        Mockito.lenient().doReturn(dummySfle).when(executorFactoryMock).getStateFinalizerExecutor(Mockito.any(),
             Mockito.any(), Mockito.any());
     }
 
-    @After
-    public void cleardown() {
+    @AfterEach
+    public void tearDown() {
         ParameterService.clear();
         ModelService.clear();
     }
 
     @Test
-    public void testStateMachineExecutor() throws StateMachineException, ContextException {
+    void testStateMachineExecutor() throws StateMachineException, ContextException {
         StateMachineExecutor executor =
             new StateMachineExecutor(executorFactoryMock, new AxArtifactKey("OwnerKey:0.0.1"));
 
@@ -290,7 +288,7 @@ public class StateMachineExecutorTest {
     }
 
     @Test
-    public void testStateOutput() throws StateMachineException {
+    void testStateOutput() throws StateMachineException {
         final StateOutput output =
             new StateOutput(axPolicy.getStateMap().get("State0").getStateOutputs().get("stateOutput0"));
         assertNotNull(output);
@@ -326,7 +324,7 @@ public class StateMachineExecutorTest {
         output.setEventFields(incomingFieldDefinitionMap, eventFieldMaps);
 
         StateOutput outputCopy = new StateOutput(axPolicy.getStateMap().get("State0")
-                .getStateOutputs().get("stateOutput0"));
+            .getStateOutputs().get("stateOutput0"));
 
         EnEvent incomingEvent = new EnEvent(new AxArtifactKey("Event0:0.0.1"));
         outputCopy.copyUnsetFields(incomingEvent);
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskExecutorTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskExecutorTest.java
index 1c4ffe4fc..da64aed49 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskExecutorTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskExecutorTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,9 +23,9 @@
 package org.onap.policy.apex.core.engine.executor;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -34,12 +34,12 @@ import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.TreeMap;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.ContextException;
 import org.onap.policy.apex.core.engine.ExecutorParameters;
 import org.onap.policy.apex.core.engine.TaskParameters;
@@ -56,10 +56,10 @@ import org.onap.policy.apex.model.policymodel.concepts.AxTaskLogic;
 import org.onap.policy.apex.model.policymodel.concepts.AxTaskParameter;
 
 /**
- * Test task excutor.
+ * Test task executor.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class TaskExecutorTest {
+@ExtendWith(MockitoExtension.class)
+class TaskExecutorTest {
     @Mock
     private AxTask axTaskMock;
 
@@ -88,27 +88,25 @@ public class TaskExecutorTest {
     @Mock
     private AxTaskLogic taskLogicMock;
 
-    private Map<String, AxField> inFieldMap;
     private Map<String, AxField> outFieldMap;
     private List<TaskParameters> taskParametersFromConfig;
-    private Map<String, AxEvent> outEvents = new TreeMap<>();
+    private final Map<String, AxEvent> outEvents = new TreeMap<>();
 
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
 
         AxArtifactKey task0Key = new AxArtifactKey("Task0:0.0.1");
-        Mockito.doReturn(task0Key).when(axTaskMock).getKey();
-        Mockito.doReturn(task0Key.getId()).when(axTaskMock).getId();
+        Mockito.lenient().doReturn(task0Key).when(axTaskMock).getKey();
+        Mockito.lenient().doReturn(task0Key.getId()).when(axTaskMock).getId();
 
-        inFieldMap = Map.of("InField0", axInputFieldMock, "InField1", axOptionalInputFieldMock);
         outFieldMap = new LinkedHashMap<>();
-
         outFieldMap.put("OutField0", axOutputFieldMock);
         outFieldMap.put("OutField1", axOptionalOutputFieldMock);
 
+        Map<String, AxField> inFieldMap = Map.of("InField0", axInputFieldMock, "InField1", axOptionalInputFieldMock);
         AxEvent inEvent = new AxEvent();
         inEvent.setParameterMap(inFieldMap);
         AxEvent outEvent = new AxEvent(new AxArtifactKey("outputEvent:1.0.0"));
@@ -116,19 +114,19 @@ public class TaskExecutorTest {
         outEvents.put(outEvent.getKey().getName(), outEvent);
 
         AxArtifactKey schemaKey = new AxArtifactKey("Schema:0.0.1");
-        Mockito.doReturn(schemaKey).when(axInputFieldMock).getSchema();
-        Mockito.doReturn(schemaKey).when(axOptionalInputFieldMock).getSchema();
-        Mockito.doReturn(schemaKey).when(axMissingOutputFieldMock).getSchema();
+        Mockito.lenient().doReturn(schemaKey).when(axInputFieldMock).getSchema();
+        Mockito.lenient().doReturn(schemaKey).when(axOptionalInputFieldMock).getSchema();
+        Mockito.lenient().doReturn(schemaKey).when(axMissingOutputFieldMock).getSchema();
 
-        Mockito.doReturn(true).when(axOptionalInputFieldMock).getOptional();
-        Mockito.doReturn(false).when(axMissingOutputFieldMock).getOptional();
+        Mockito.lenient().doReturn(true).when(axOptionalInputFieldMock).getOptional();
+        Mockito.lenient().doReturn(false).when(axMissingOutputFieldMock).getOptional();
 
-        Mockito.doReturn(taskLogicMock).when(axTaskMock).getTaskLogic();
+        Mockito.lenient().doReturn(taskLogicMock).when(axTaskMock).getTaskLogic();
 
-        Mockito.doReturn(inEvent).when(axTaskMock).getInputEvent();
-        Mockito.doReturn(outEvents).when(axTaskMock).getOutputEvents();
+        Mockito.lenient().doReturn(inEvent).when(axTaskMock).getInputEvent();
+        Mockito.lenient().doReturn(outEvents).when(axTaskMock).getOutputEvents();
 
-        Mockito.doReturn(new AxArtifactKey("Context:0.0.1")).when(internalContextMock).getKey();
+        Mockito.lenient().doReturn(new AxArtifactKey("Context:0.0.1")).when(internalContextMock).getKey();
 
         Map<String, AxTaskParameter> taskParameters = new HashMap<>();
         taskParameters.put("parameterKey2", new AxTaskParameter(new AxReferenceKey(), "parameterOriginalValue2"));
@@ -141,29 +139,29 @@ public class TaskExecutorTest {
     }
 
     @Test
-    public void testTaskExecutor() throws StateMachineException, ContextException {
+    void testTaskExecutor() throws StateMachineException, ContextException {
         final DummyTaskExecutor executor = new DummyTaskExecutor();
         executor.setContext(null, axTaskMock, internalContextMock);
         assertEquals("Task0:0.0.1", executor.getKey().getId());
-        assertEquals(null, executor.getExecutionContext());
-        assertEquals(null, executor.getParent());
+        assertNull(executor.getExecutionContext());
+        assertNull(executor.getParent());
         assertEquals(internalContextMock, executor.getContext());
-        assertEquals(null, executor.getNext());
-        assertEquals(null, executor.getIncoming());
-        assertEquals(null, executor.getOutgoing());
+        assertNull(executor.getNext());
+        assertNull(executor.getIncoming());
+        assertNull(executor.getOutgoing());
         assertNotNull(executor.getSubject());
 
         executor.setParameters(new ExecutorParameters());
         executor.setNext(nextExecutorMock);
         assertEquals(nextExecutorMock, executor.getNext());
         executor.setNext(null);
-        assertEquals(null, executor.getNext());
+        assertNull(executor.getNext());
 
-        assertThatThrownBy(() -> executor.cleanUp()).hasMessageContaining("cleanUp() not implemented on class");
+        assertThatThrownBy(executor::cleanUp).hasMessageContaining("cleanUp() not implemented on class");
 
         Mockito.doReturn(null).when(taskLogicMock).getLogic();
 
-        assertThatThrownBy(() -> executor.prepare()).hasMessageContaining("task logic cannot be null.");
+        assertThatThrownBy(executor::prepare).hasMessageContaining("task logic cannot be null.");
 
         Mockito.doReturn("some task logic").when(taskLogicMock).getLogic();
 
@@ -220,19 +218,19 @@ public class TaskExecutorTest {
     }
 
     @Test
-    public void testTaskExecutorForTaskParameters() {
-        DummyTaskExecutor executorForParmeterTest = new DummyTaskExecutor(false);
+    void testTaskExecutorForTaskParameters() {
+        DummyTaskExecutor executorForParameterTest = new DummyTaskExecutor(false);
 
-        executorForParmeterTest.setContext(null, axTaskMock, internalContextMock);
-        executorForParmeterTest.updateTaskParameters(taskParametersFromConfig);
-        assertNotNull(executorForParmeterTest.getSubject().getTaskParameters());
+        executorForParameterTest.setContext(null, axTaskMock, internalContextMock);
+        executorForParameterTest.updateTaskParameters(taskParametersFromConfig);
+        assertNotNull(executorForParameterTest.getSubject().getTaskParameters());
         // taskId matched, parameter value updated with the new value
         assertEquals("parameterNewValue0",
-            executorForParmeterTest.getSubject().getTaskParameters().get("parameterKey0").getTaskParameterValue());
+            executorForParameterTest.getSubject().getTaskParameters().get("parameterKey0").getTaskParameterValue());
         // taskId mismatch, so the parameter is not updated in the task
-        assertNull(executorForParmeterTest.getSubject().getTaskParameters().get("parameterKey1"));
+        assertNull(executorForParameterTest.getSubject().getTaskParameters().get("parameterKey1"));
         // taskId is not available, so parameter is updated in the task
         assertEquals("parameterNewValue2",
-            executorForParmeterTest.getSubject().getTaskParameters().get("parameterKey2").getTaskParameterValue());
+            executorForParameterTest.getSubject().getTaskParameters().get("parameterKey2").getTaskParameterValue());
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskSelectExecutorTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskSelectExecutorTest.java
index cf3c59fa9..6f0d74e66 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskSelectExecutorTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/TaskSelectExecutorTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,17 +22,18 @@
 package org.onap.policy.apex.core.engine.executor;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Properties;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.core.engine.ExecutorParameters;
 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
 import org.onap.policy.apex.core.engine.event.EnEvent;
@@ -46,8 +47,8 @@ import org.onap.policy.apex.model.policymodel.concepts.AxTaskSelectionLogic;
 /**
  * Test task executor.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class TaskSelectExecutorTest {
+@ExtendWith(MockitoExtension.class)
+class TaskSelectExecutorTest {
     @Mock
     private AxState axStateMock;
 
@@ -66,8 +67,8 @@ public class TaskSelectExecutorTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
 
         AxReferenceKey state0Key = new AxReferenceKey("State0Parent:0.0.1:Parent:State0");
         Mockito.doReturn(state0Key).when(axStateMock).getKey();
@@ -82,24 +83,24 @@ public class TaskSelectExecutorTest {
     }
 
     @Test
-    public void testTaskSelectionExecutor() throws StateMachineException {
+    void testTaskSelectionExecutor() throws StateMachineException {
         DummyTaskSelectExecutor executor = new DummyTaskSelectExecutor();
 
         executor.setContext(null, axStateMock, internalContextMock);
         assertEquals("State0Parent:0.0.1:Parent:State0", executor.getKey().getId());
-        assertEquals(null, executor.getExecutionContext());
-        assertEquals(null, executor.getParent());
+        assertNull(executor.getExecutionContext());
+        assertNull(executor.getParent());
         assertEquals(internalContextMock, executor.getContext());
-        assertEquals(null, executor.getNext());
-        assertEquals(null, executor.getIncoming());
-        assertEquals(null, executor.getOutgoing());
+        assertNull(executor.getNext());
+        assertNull(executor.getIncoming());
+        assertNull(executor.getOutgoing());
         assertEquals(axStateMock, executor.getSubject());
 
         executor.setParameters(new ExecutorParameters());
         executor.setNext(nextExecutorMock);
         assertEquals(nextExecutorMock, executor.getNext());
         executor.setNext(null);
-        assertEquals(null, executor.getNext());
+        assertNull(executor.getNext());
 
         assertThatThrownBy(executor::cleanUp)
             .hasMessage("cleanUp() not implemented on class");
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxStateFacadeTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxStateFacadeTest.java
index 54013e943..6744534d7 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxStateFacadeTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxStateFacadeTest.java
@@ -1,37 +1,37 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2023 Nordix Foundation.
+ *  Modifications Copyright (C) 2023-2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
 
 package org.onap.policy.apex.core.engine.executor.context;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 import java.util.LinkedHashMap;
 import java.util.Map;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
 import org.onap.policy.apex.model.basicmodel.service.ModelService;
@@ -42,8 +42,8 @@ import org.onap.policy.apex.model.policymodel.concepts.AxTasks;
 /**
  * Test the state facade.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class AxStateFacadeTest {
+@ExtendWith(MockitoExtension.class)
+class AxStateFacadeTest {
     @Mock
     private AxState axStateMock;
 
@@ -53,32 +53,33 @@ public class AxStateFacadeTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
         AxReferenceKey stateKey = new AxReferenceKey("StateParent:0.0.1:ParentName:StateName");
         Mockito.doReturn(stateKey).when(axStateMock).getKey();
 
         AxArtifactKey task0Key = new AxArtifactKey("Task0:0.0.1");
         Mockito.doReturn(task0Key).when(axStateMock).getDefaultTask();
-        
-        Map<AxArtifactKey, Object> taskReferences = new LinkedHashMap<>();;
+
+        Map<AxArtifactKey, Object> taskReferences = new LinkedHashMap<>();
+        ;
         taskReferences.put(task0Key, null);
         Mockito.doReturn(taskReferences).when(axStateMock).getTaskReferences();
 
         AxTasks tasks = new AxTasks();
         tasks.getTaskMap().put(task0Key, axTaskMock);
-        
+
         ModelService.registerModel(AxTasks.class, tasks);
         Mockito.doReturn(task0Key).when(axTaskMock).getKey();
     }
 
     @Test
-    public void testAxStateFacade() {
+    void testAxStateFacade() {
         AxStateFacade stateFacade = new AxStateFacade(axStateMock);
-        
+
         assertEquals("StateName", stateFacade.getStateName());
         assertEquals("StateParent:0.0.1:ParentName:StateName", stateFacade.getId());
-        
+
         assertEquals("Task0", stateFacade.getDefaultTaskKey().getName());
         assertNull(stateFacade.getTaskKey(null));
         assertEquals("Task0", stateFacade.getTaskKey("Task0").getName());
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacadeTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacadeTest.java
index 634b3b35c..8d17d9f87 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacadeTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacadeTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,18 +23,18 @@
 package org.onap.policy.apex.core.engine.executor.context;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import java.util.Map;
 import java.util.TreeMap;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.parameters.ContextParameterConstants;
 import org.onap.policy.apex.context.parameters.SchemaParameters;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
@@ -52,8 +52,8 @@ import org.onap.policy.common.parameters.ParameterService;
 /**
  * Test the state facade.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class AxTaskFacadeTest {
+@ExtendWith(MockitoExtension.class)
+class AxTaskFacadeTest {
     @Mock
     private AxTask axTaskMock;
 
@@ -72,8 +72,8 @@ public class AxTaskFacadeTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
         AxContextSchemas schemas = new AxContextSchemas();
 
         AxArtifactKey stringTypeKey = new AxArtifactKey("StringType:0.0.1");
@@ -108,14 +108,14 @@ public class AxTaskFacadeTest {
         ParameterService.register(new SchemaParameters());
     }
 
-    @After
-    public void teardown() {
+    @AfterEach
+    void teardown() {
         ParameterService.deregister(ContextParameterConstants.SCHEMA_GROUP_NAME);
         ModelService.clear();
     }
 
     @Test
-    public void testAxStateFacade() {
+    void testAxStateFacade() {
         AxTaskFacade taskFacade = new AxTaskFacade(axTaskMock);
 
         assertEquals("Task0", taskFacade.getTaskName());
@@ -123,18 +123,18 @@ public class AxTaskFacadeTest {
 
         assertThatThrownBy(() -> taskFacade.getInFieldSchemaHelper("InFieldDoesntExist"))
             .hasMessage("no incoming field with name \"InFieldDoesntExist\" " + "defined on task "
-                    + "\"Task0:0.0.1\"");
+                + "\"Task0:0.0.1\"");
         assertThatThrownBy(() -> taskFacade.getOutFieldSchemaHelper("OutFieldDoesntExist"))
             .hasMessage("no outgoing field with name \"OutFieldDoesntExist\" " + "defined on task "
-                    + "\"Task0:0.0.1\"");
+                + "\"Task0:0.0.1\"");
         assertNotNull(taskFacade.getInFieldSchemaHelper("InField0"));
         assertNotNull(taskFacade.getOutFieldSchemaHelper("OutField0"));
 
         assertThatThrownBy(() -> taskFacade.getInFieldSchemaHelper("InFieldBad"))
             .hasMessage("schema helper cannot be created for task field \"InFieldBad\" "
-                    + "with key \"null\" with schema \"null\"");
+                + "with key \"null\" with schema \"null\"");
         assertThatThrownBy(() -> taskFacade.getOutFieldSchemaHelper("OutFieldBad"))
             .hasMessage("schema helper cannot be created for task field \"OutFieldBad\" "
-                    + "with key \"null\" with schema \"null\"");
+                + "with key \"null\" with schema \"null\"");
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/DummyContextAlbum.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/DummyContextAlbum.java
index efb53a682..2570dde1d 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/DummyContextAlbum.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/DummyContextAlbum.java
@@ -2,6 +2,7 @@
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
  *  Modifications Copyright (C) 2021 AT&T Intellectual Property. All rights reserved.
+ * Modifications Copyright (C) 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,7 +28,6 @@ import java.util.Set;
 import lombok.AllArgsConstructor;
 import org.apache.commons.lang3.NotImplementedException;
 import org.onap.policy.apex.context.ContextAlbum;
-import org.onap.policy.apex.context.ContextException;
 import org.onap.policy.apex.context.SchemaHelper;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
@@ -172,7 +172,7 @@ public class DummyContextAlbum implements ContextAlbum {
      * {@inheritDoc}.
      */
     @Override
-    public void lockForReading(String key) throws ContextException {
+    public void lockForReading(String key) {
         throw new NotImplementedException("Not implemented on dummy class");
     }
 
@@ -180,7 +180,7 @@ public class DummyContextAlbum implements ContextAlbum {
      * {@inheritDoc}.
      */
     @Override
-    public void lockForWriting(String key) throws ContextException {
+    public void lockForWriting(String key) {
         throw new NotImplementedException("Not implemented on dummy class");
     }
 
@@ -188,7 +188,7 @@ public class DummyContextAlbum implements ContextAlbum {
      * {@inheritDoc}.
      */
     @Override
-    public void unlockForReading(String key) throws ContextException {
+    public void unlockForReading(String key) {
         throw new NotImplementedException("Not implemented on dummy class");
     }
 
@@ -196,7 +196,7 @@ public class DummyContextAlbum implements ContextAlbum {
      * {@inheritDoc}.
      */
     @Override
-    public void unlockForWriting(String key) throws ContextException {
+    public void unlockForWriting(String key) {
         throw new NotImplementedException("Not implemented on dummy class");
     }
 
@@ -220,7 +220,7 @@ public class DummyContextAlbum implements ContextAlbum {
      * {@inheritDoc}.
      */
     @Override
-    public void flush() throws ContextException {
+    public void flush() {
         throw new NotImplementedException("Not implemented on dummy class");
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContextTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContextTest.java
index 9c6aa2f07..8c008ba2d 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContextTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContextTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,19 +22,19 @@
 package org.onap.policy.apex.core.engine.executor.context;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.ContextAlbum;
 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
 import org.onap.policy.apex.core.engine.executor.StateFinalizerExecutor;
@@ -45,8 +45,8 @@ import org.onap.policy.apex.model.policymodel.concepts.AxState;
 /**
  * Test Task Execution Context.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class StateFinalizerExecutionContextTest {
+@ExtendWith(MockitoExtension.class)
+class StateFinalizerExecutionContextTest {
     @Mock
     private StateFinalizerExecutor stateFinalizerExecutorMock;
 
@@ -62,8 +62,8 @@ public class StateFinalizerExecutionContextTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
 
         Set<AxArtifactKey> contextAlbumReferences = new LinkedHashSet<>();
         contextAlbumReferences.add(new AxArtifactKey(("AlbumKey0:0.0.1")));
@@ -86,12 +86,12 @@ public class StateFinalizerExecutionContextTest {
     }
 
     @Test
-    public void test() {
+    void test() {
         final Map<String, Object> fields = new LinkedHashMap<>();
         final Set<String> stateOutputNames = new LinkedHashSet<>();
 
         StateFinalizerExecutionContext sfec = new StateFinalizerExecutionContext(stateFinalizerExecutorMock, 0, null,
-                        axStateMock, fields, stateOutputNames, internalContextMock);
+            axStateMock, fields, stateOutputNames, internalContextMock);
 
         assertNotNull(sfec);
         sfec.setMessage("SFEC Message");
@@ -103,8 +103,8 @@ public class StateFinalizerExecutionContextTest {
         ContextAlbum contextAlbum = sfec.getContextAlbum("AlbumKey0");
         assertEquals("AlbumKey0:0.0.1", contextAlbum.getKey().getId());
 
-        assertThatThrownBy(() -> sfec.getContextAlbum("AlbumKeyNonExistant"))
-            .hasMessage("cannot find definition of context album \"AlbumKeyNonExistant\" "
-                            + "on state \"Parent:0.0.1:ParentName:StateName\"");
+        assertThatThrownBy(() -> sfec.getContextAlbum("AlbumKeyNonExistent"))
+            .hasMessage("cannot find definition of context album \"AlbumKeyNonExistent\" "
+                + "on state \"Parent:0.0.1:ParentName:StateName\"");
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContextTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContextTest.java
index 7f813cc01..3b76249b7 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContextTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContextTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation.
  *  Modifications Copyright (C) 2021 Bell Canada. All rights reserved.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -23,8 +23,8 @@
 package org.onap.policy.apex.core.engine.executor.context;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -33,12 +33,12 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.ContextAlbum;
 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
 import org.onap.policy.apex.core.engine.executor.TaskExecutor;
@@ -50,8 +50,8 @@ import org.onap.policy.apex.model.policymodel.concepts.AxTaskParameter;
 /**
  * Test Task Execution Context.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class TaskExecutionContextTest {
+@ExtendWith(MockitoExtension.class)
+class TaskExecutionContextTest {
     @Mock
     private TaskExecutor taskExecutorMock;
 
@@ -67,8 +67,8 @@ public class TaskExecutionContextTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
 
         Set<AxArtifactKey> contextAlbumReferences = new LinkedHashSet<>();
         contextAlbumReferences.add(new AxArtifactKey(("AlbumKey0:0.0.1")));
@@ -95,7 +95,7 @@ public class TaskExecutionContextTest {
     }
 
     @Test
-    public void test() {
+    void test() {
         final Map<String, Object> inFields = new LinkedHashMap<>();
         final List<Map<String, Object>> outFieldsList = new LinkedList<>();
 
@@ -113,7 +113,7 @@ public class TaskExecutionContextTest {
         assertEquals("parameterValue1", parameters.get("parameterKey1"));
         assertEquals("parameterValue2", parameters.get("parameterKey2"));
 
-        assertThatThrownBy(() -> tec.getContextAlbum("AlbumKeyNonExistant"))
-            .hasMessageContaining("cannot find definition of context album \"AlbumKeyNonExistant\" on task \"null\"");
+        assertThatThrownBy(() -> tec.getContextAlbum("AlbumKeyNonExistent"))
+            .hasMessageContaining("cannot find definition of context album \"AlbumKeyNonExistent\" on task \"null\"");
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContextTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContextTest.java
index 84f4817e0..b21dae10b 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContextTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContextTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,19 +22,19 @@
 package org.onap.policy.apex.core.engine.executor.context;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.context.ContextAlbum;
 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
 import org.onap.policy.apex.core.engine.event.EnEvent;
@@ -46,8 +46,8 @@ import org.onap.policy.apex.model.policymodel.concepts.AxState;
 /**
  * Test Task Execution Context.
  */
-@RunWith(MockitoJUnitRunner.class)
-public class TaskSelectionExecutionContextTest {
+@ExtendWith(MockitoExtension.class)
+class TaskSelectionExecutionContextTest {
     @Mock
     private TaskSelectExecutor taskSelectExecutorMock;
 
@@ -66,8 +66,8 @@ public class TaskSelectionExecutionContextTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
 
         Set<AxArtifactKey> contextAlbumReferences = new LinkedHashSet<>();
         contextAlbumReferences.add(new AxArtifactKey(("AlbumKey0:0.0.1")));
@@ -90,11 +90,11 @@ public class TaskSelectionExecutionContextTest {
     }
 
     @Test
-    public void test() {
+    void test() {
         final AxArtifactKey outgoingEventKey = new AxArtifactKey("OutEvent:0.0.1");
 
         TaskSelectionExecutionContext tsec = new TaskSelectionExecutionContext(taskSelectExecutorMock, 0, axStateMock,
-                        incomingEventMock, outgoingEventKey, internalContextMock);
+            incomingEventMock, outgoingEventKey, internalContextMock);
 
         assertNotNull(tsec);
         tsec.setMessage("TSEC Message");
@@ -103,8 +103,8 @@ public class TaskSelectionExecutionContextTest {
         ContextAlbum contextAlbum = tsec.getContextAlbum("AlbumKey0");
         assertEquals("AlbumKey0:0.0.1", contextAlbum.getKey().getId());
 
-        assertThatThrownBy(() -> tsec.getContextAlbum("AlbumKeyNonExistant"))
-            .hasMessage("cannot find definition of context album \"AlbumKeyNonExistant\" "
-                            + "on state \"Parent:0.0.1:ParentName:StateName\"");
+        assertThatThrownBy(() -> tsec.getContextAlbum("AlbumKeyNonExistent"))
+            .hasMessage("cannot find definition of context album \"AlbumKeyNonExistent\" "
+                + "on state \"Parent:0.0.1:ParentName:StateName\"");
     }
 }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/exception/StateMachineRuntimeExceptionTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/exception/StateMachineRuntimeExceptionTest.java
index 84f330308..35687c18d 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/exception/StateMachineRuntimeExceptionTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/exception/StateMachineRuntimeExceptionTest.java
@@ -1,41 +1,41 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * Modifications Copyright (C) 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  * SPDX-License-Identifier: Apache-2.0
  * ============LICENSE_END=========================================================
  */
 
 package org.onap.policy.apex.core.engine.executor.exception;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import java.io.IOException;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 /**
  * Test state machine runtime exception.
- *
  */
-public class StateMachineRuntimeExceptionTest {
+class StateMachineRuntimeExceptionTest {
 
     @Test
-    public void testException() {
+    void testException() {
         StateMachineRuntimeException smre = new StateMachineRuntimeException("Exception Message");
         assertEquals("Exception Message", smre.getMessage());
-        
+
         smre = new StateMachineRuntimeException("Exception Message", new IOException());
         assertEquals("Exception Message", smre.getMessage());
     }
diff --git a/core/src/test/java/org/onap/policy/apex/core/engine/executor/impl/ExceutorFactoryImplTest.java b/core/src/test/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImplTest.java
index c8aa7eb08..f7020dd21 100644
--- a/core/src/test/java/org/onap/policy/apex/core/engine/executor/impl/ExceutorFactoryImplTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImplTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020, 2023 Nordix Foundation
+ *  Modifications Copyright (C) 2020, 2023-2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,16 +22,16 @@
 package org.onap.policy.apex.core.engine.executor.impl;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertNull;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.mockito.junit.jupiter.MockitoExtension;
 import org.onap.policy.apex.core.engine.EngineParameters;
 import org.onap.policy.apex.core.engine.ExecutorParameters;
 import org.onap.policy.apex.core.engine.context.ApexInternalContext;
@@ -46,10 +46,9 @@ import org.onap.policy.common.parameters.ParameterService;
 
 /**
  * Test the executor factory implementation.
- *
  */
-@RunWith(MockitoJUnitRunner.class)
-public class ExceutorFactoryImplTest {
+@ExtendWith(MockitoExtension.class)
+class ExecutorFactoryImplTest {
     @Mock
     private ApexInternalContext internalContextMock;
 
@@ -76,28 +75,28 @@ public class ExceutorFactoryImplTest {
     /**
      * Set up mocking.
      */
-    @Before
-    public void startMocking() {
+    @BeforeEach
+    void startMocking() {
 
-        Mockito.doReturn(tslMock).when(stateMock).getTaskSelectionLogic();
-        Mockito.doReturn("Dummy").when(tslMock).getLogicFlavour();
+        Mockito.lenient().doReturn(tslMock).when(stateMock).getTaskSelectionLogic();
+        Mockito.lenient().doReturn("Dummy").when(tslMock).getLogicFlavour();
 
-        Mockito.doReturn(tlMock).when(taskMock).getTaskLogic();
-        Mockito.doReturn("Dummy").when(tlMock).getLogicFlavour();
+        Mockito.lenient().doReturn(tlMock).when(taskMock).getTaskLogic();
+        Mockito.lenient().doReturn("Dummy").when(tlMock).getLogicFlavour();
 
-        Mockito.doReturn("Dummy").when(sflMock).getLogicFlavour();
+        Mockito.lenient().doReturn("Dummy").when(sflMock).getLogicFlavour();
     }
 
-    @After
-    public void clearPars() {
+    @AfterEach
+    void clearPars() {
         ParameterService.clear();
     }
 
     @Test
-    public void testExecutorFactoryImplGood() throws StateMachineException {
+    void testExecutorFactoryImplGood() throws StateMachineException {
         setGoodPars();
 
-        ExecutorFactoryImpl factory = null;
+        ExecutorFactoryImpl factory;
 
         factory = new ExecutorFactoryImpl();
 
@@ -112,52 +111,52 @@ public class ExceutorFactoryImplTest {
     }
 
     @Test
-    public void testExecutorFactoryImplNonExistant() {
-        setNonExistantPars();
+    void testExecutorFactoryImplNonExistent() {
+        setNonExistentPars();
 
-        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+        assertThatThrownBy(ExecutorFactoryImpl::new)
             .hasMessage("Apex executor class not found for executor plugin "
-                            + "\"org.onap.policy.apex.core.engine.executor.BadTaskExecutor\"");
+                + "\"org.onap.policy.apex.core.engine.executor.BadTaskExecutor\"");
         executorPars.setTaskExecutorPluginClass(null);
 
-        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+        assertThatThrownBy(ExecutorFactoryImpl::new)
             .hasMessage("Apex executor class not found for executor plugin "
-                    + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"");
+                + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"");
         executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyTaskExecutor");
 
-        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+        assertThatThrownBy(ExecutorFactoryImpl::new)
             .hasMessage("Apex executor class not found for executor plugin "
-                    + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"");
+                + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"");
         executorPars.setTaskSelectionExecutorPluginClass(
-                        "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
+            "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
 
-        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+        assertThatThrownBy(ExecutorFactoryImpl::new)
             .hasMessage("Apex executor class not found for executor plugin "
-                    + "\"org.onap.policy.apex.core.engine.executor.BadStateFinalizerExecutor\"");
+                + "\"org.onap.policy.apex.core.engine.executor.BadStateFinalizerExecutor\"");
     }
 
     @Test
-    public void testExecutorFactoryImplBad() {
+    void testExecutorFactoryImplBad() {
         setBadPars();
 
-        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+        assertThatThrownBy(ExecutorFactoryImpl::new)
             .hasMessage("Specified Apex executor plugin class \"java.lang.String\" "
-                    + "does not implment the Executor interface");
+                + "does not implement the Executor interface");
         executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyTaskExecutor");
 
-        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+        assertThatThrownBy(ExecutorFactoryImpl::new)
             .hasMessage("Specified Apex executor plugin class \"java.lang.String\" "
-                    + "does not implment the Executor interface");
+                + "does not implement the Executor interface");
         executorPars.setTaskSelectionExecutorPluginClass(
-                        "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
+            "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
 
-        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+        assertThatThrownBy(ExecutorFactoryImpl::new)
             .hasMessage("Specified Apex executor plugin class \"java.lang.String\" "
-                    + "does not implment the Executor interface");
+                + "does not implement the Executor interface");
     }
 
     @Test
-    public void testExecutorFactoryCreateErrors() throws StateMachineException {
+    void testExecutorFactoryCreateErrors() throws StateMachineException {
         setGoodPars();
 
         executorPars.setTaskExecutorPluginClass(null);
@@ -166,23 +165,23 @@ public class ExceutorFactoryImplTest {
 
         assertThatThrownBy(() -> factory.getTaskExecutor(null, taskMock, internalContextMock))
             .hasMessage("Executor plugin class not defined for \"Dummy\" executor of type "
-                    + "\"org.onap.policy.apex.core.engine.executor.TaskExecutor\"");
+                + "\"org.onap.policy.apex.core.engine.executor.TaskExecutor\"");
         executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyFailingTaskExecutor");
 
         ExecutorFactoryImpl factoryInitError = new ExecutorFactoryImpl();
 
         assertThatThrownBy(() -> factoryInitError.getTaskExecutor(null, taskMock, internalContextMock))
             .hasMessage("Instantiation error on \"Dummy\" executor of type "
-                    + "\"org.onap.policy.apex.core.engine.executor.DummyFailingTaskExecutor\"");
+                + "\"org.onap.policy.apex.core.engine.executor.DummyFailingTaskExecutor\"");
         executorPars.setTaskExecutorPluginClass(
-                        "org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor");
+            "org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor");
 
         ExecutorFactoryImpl factoryDummyError = new ExecutorFactoryImpl();
 
         assertThatThrownBy(() -> factoryDummyError.getTaskExecutor(null, taskMock, internalContextMock))
             .hasMessage("Executor on \"Dummy\" "
-                    + "of type \"class org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor\""
-                    + " is not an instance of \"org.onap.policy.apex.core.engine.executor.TaskExecutor\"");
+                + "of type \"class org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor\""
+                + " is not an instance of \"org.onap.policy.apex.core.engine.executor.TaskExecutor\"");
     }
 
     /**
@@ -192,9 +191,9 @@ public class ExceutorFactoryImplTest {
         executorPars = new ExecutorParameters();
         executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyTaskExecutor");
         executorPars.setTaskSelectionExecutorPluginClass(
-                        "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
+            "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
         executorPars.setStateFinalizerExecutorPluginClass(
-                        "org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor");
+            "org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor");
 
         EngineParameters enginePars = new EngineParameters();
         enginePars.getExecutorParameterMap().put("Dummy", executorPars);
@@ -204,15 +203,15 @@ public class ExceutorFactoryImplTest {
     }
 
     /**
-     * Set up non existant parameters.
+     * Set up non existent parameters.
      */
-    private void setNonExistantPars() {
+    private void setNonExistentPars() {
         executorPars = new ExecutorParameters();
         executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.BadTaskExecutor");
         executorPars.setTaskSelectionExecutorPluginClass(
-                        "org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor");
+            "org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor");
         executorPars.setStateFinalizerExecutorPluginClass(
-                        "org.onap.policy.apex.core.engine.executor.BadStateFinalizerExecutor");
+            "org.onap.policy.apex.core.engine.executor.BadStateFinalizerExecutor");
 
         EngineParameters enginePars = new EngineParameters();
         enginePars.getExecutorParameterMap().put("Dummy", executorPars);
diff --git a/core/src/test/java/org/onap/policy/apex/core/infrastructure/threading/ThreadingTest.java b/core/src/test/java/org/onap/policy/apex/core/infrastructure/threading/ThreadingTest.java
index 35ad9386a..356b800a8 100644
--- a/core/src/test/java/org/onap/policy/apex/core/infrastructure/threading/ThreadingTest.java
+++ b/core/src/test/java/org/onap/policy/apex/core/infrastructure/threading/ThreadingTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2020, 2024 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,12 +21,12 @@
 
 package org.onap.policy.apex.core.infrastructure.threading;
 
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.ArrayList;
 import java.util.List;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 import org.slf4j.ext.XLogger;
 import org.slf4j.ext.XLoggerFactory;
 
@@ -35,7 +35,7 @@ import org.slf4j.ext.XLoggerFactory;
  *
  * @author Liam Fallon (liam.fallon@ericsson.com)
  */
-public class ThreadingTest {
+class ThreadingTest {
 
     private static final String LOCAL_NAME = "localName";
     // Logger for this class
@@ -45,18 +45,18 @@ public class ThreadingTest {
      * Test thread factory initialization.
      */
     @Test
-    public void testThreadFactoryInitialization() {
+    void testThreadFactoryInitialization() {
         final ApplicationThreadFactory objUnderTest = new ApplicationThreadFactory(LOCAL_NAME, 0);
-        assertNotNull("Failed to create ApplicationThreadFactory threadFactory0", objUnderTest);
+        assertNotNull(objUnderTest, "Failed to create ApplicationThreadFactory threadFactory0");
         logger.debug(objUnderTest.toString());
-        assertTrue("Failed to name ApplicationThreadFactory threadFactory0",
-                objUnderTest.getName().startsWith("Apex-" + LOCAL_NAME));
+        assertTrue(objUnderTest.getName().startsWith("Apex-" + LOCAL_NAME),
+            "Failed to name ApplicationThreadFactory threadFactory0");
 
         final ApplicationThreadFactory objUnderTest1 = new ApplicationThreadFactory(LOCAL_NAME, 0);
-        assertNotNull("Failed to create ApplicationThreadFactory threadFactory1", objUnderTest1);
+        assertNotNull(objUnderTest1, "Failed to create ApplicationThreadFactory threadFactory1");
         logger.debug(objUnderTest1.toString());
-        assertTrue("Failed to name ApplicationThreadFactory threadFactory1",
-                objUnderTest1.getName().startsWith("Apex-" + LOCAL_NAME));
+        assertTrue(objUnderTest1.getName().startsWith("Apex-" + LOCAL_NAME),
+            "Failed to name ApplicationThreadFactory threadFactory1");
 
         testThreadFactory(objUnderTest);
         testThreadFactory(objUnderTest1);