Increase code coverage in policy-management

Issue-ID: POLICY-5068
Change-Id: Ie7ac44a948fe559306b1aa3a403d888c352be7f2
Signed-off-by: adheli.tavares <adheli.tavares@est.tech>

10 files changed, 186 insertions, 315 deletions

diff --git a/policy-management/src/main/java/org/onap/policy/drools/controller/IndexedDroolsControllerFactory.java b/policy-management/src/main/java/org/onap/policy/drools/controller/IndexedDroolsControllerFactory.java
index 7f28f9bb..a6459d67 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/controller/IndexedDroolsControllerFactory.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/controller/IndexedDroolsControllerFactory.java
@@ -28,6 +28,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import lombok.NonNull;
+import org.apache.commons.lang3.StringUtils;
 import org.onap.policy.common.endpoints.event.comm.Topic;
 import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
 import org.onap.policy.common.endpoints.event.comm.TopicSink;
@@ -62,7 +63,7 @@ class IndexedDroolsControllerFactory implements DroolsControllerFactory {
     /**
      * Null Drools Controller.
      */
-    protected NullDroolsController nullDroolsController = new NullDroolsController();
+    protected NullDroolsController nullDroolsController;
 
     /**
      * Constructs the object.
@@ -71,11 +72,11 @@ class IndexedDroolsControllerFactory implements DroolsControllerFactory {
 
         /* Add a NULL controller which will always be present in the hash */
 
-        DroolsController controller = new NullDroolsController();
-        String controllerId = controller.getGroupId() + ":" + controller.getArtifactId();
+        nullDroolsController = new NullDroolsController();
+        String controllerId = nullDroolsController.getGroupId() + ":" + nullDroolsController.getArtifactId();
 
         synchronized (this) {
-            droolsControllers.put(controllerId, controller);
+            droolsControllers.put(controllerId, nullDroolsController);
         }
     }
 
@@ -84,17 +85,17 @@ class IndexedDroolsControllerFactory implements DroolsControllerFactory {
             List<? extends TopicSink> eventSinks) throws LinkageError {
 
         String groupId = properties.getProperty(DroolsPropertyConstants.RULES_GROUPID);
-        if (groupId == null || groupId.isEmpty()) {
+        if (StringUtils.isBlank(groupId)) {
             groupId = DroolsControllerConstants.NO_GROUP_ID;
         }
 
         String artifactId = properties.getProperty(DroolsPropertyConstants.RULES_ARTIFACTID);
-        if (artifactId == null || artifactId.isEmpty()) {
+        if (StringUtils.isBlank(artifactId)) {
             artifactId = DroolsControllerConstants.NO_ARTIFACT_ID;
         }
 
         String version = properties.getProperty(DroolsPropertyConstants.RULES_VERSION);
-        if (version == null || version.isEmpty()) {
+        if (StringUtils.isBlank(version)) {
             version = DroolsControllerConstants.NO_VERSION;
         }
 
@@ -110,15 +111,15 @@ class IndexedDroolsControllerFactory implements DroolsControllerFactory {
             List<TopicCoderFilterConfiguration> decoderConfigurations,
             List<TopicCoderFilterConfiguration> encoderConfigurations) throws LinkageError {
 
-        if (newGroupId == null || newGroupId.isEmpty()) {
+        if (StringUtils.isBlank(newGroupId)) {
             throw new IllegalArgumentException("Missing maven group-id coordinate");
         }
 
-        if (newArtifactId == null || newArtifactId.isEmpty()) {
+        if (StringUtils.isBlank(newArtifactId)) {
             throw new IllegalArgumentException("Missing maven artifact-id coordinate");
         }
 
-        if (newVersion == null || newVersion.isEmpty()) {
+        if (StringUtils.isBlank(newVersion)) {
             throw new IllegalArgumentException("Missing maven version coordinate");
         }
 
@@ -240,7 +241,7 @@ class IndexedDroolsControllerFactory implements DroolsControllerFactory {
             String eventClasses = properties
                     .getProperty(propertyTopicEntityPrefix + PolicyEndPointProperties.PROPERTY_TOPIC_EVENTS_SUFFIX);
 
-            if (eventClasses == null || eventClasses.isEmpty()) {
+            if (StringUtils.isBlank(eventClasses)) {
                 logger.warn("There are no event classes for topic {}", firstTopic);
                 continue;
             }
@@ -280,7 +281,7 @@ class IndexedDroolsControllerFactory implements DroolsControllerFactory {
                 + PolicyEndPointProperties.PROPERTY_TOPIC_EVENTS_CUSTOM_MODEL_CODER_GSON_SUFFIX);
 
         CustomGsonCoder customGsonCoder = null;
-        if (customGson != null && !customGson.isEmpty()) {
+        if (StringUtils.isNotBlank(customGson)) {
             try {
                 customGsonCoder = new CustomGsonCoder(customGson);
             } catch (IllegalArgumentException e) {
@@ -375,7 +376,7 @@ class IndexedDroolsControllerFactory implements DroolsControllerFactory {
     @Override
     public DroolsController get(String groupId, String artifactId, String version) {
 
-        if (groupId == null || artifactId == null || groupId.isEmpty() || artifactId.isEmpty()) {
+        if (StringUtils.isBlank(groupId) || StringUtils.isBlank(artifactId)) {
             throw new IllegalArgumentException("Missing maven coordinates: " + groupId + ":" + artifactId);
         }
 
diff --git a/policy-management/src/main/java/org/onap/policy/drools/controller/internal/MavenDroolsController.java b/policy-management/src/main/java/org/onap/policy/drools/controller/internal/MavenDroolsController.java
index 68a69159..aa701dfd 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/controller/internal/MavenDroolsController.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/controller/internal/MavenDroolsController.java
@@ -3,7 +3,7 @@
  * ONAP
  * ================================================================================
  * Copyright (C) 2017-2021 AT&T Intellectual Property. 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.
@@ -31,6 +31,7 @@ import java.util.stream.Collectors;
 import lombok.Getter;
 import lombok.NonNull;
 import org.apache.commons.collections4.queue.CircularFifoQueue;
+import org.apache.commons.lang3.StringUtils;
 import org.drools.core.ClassObjectFilter;
 import org.kie.api.definition.KiePackage;
 import org.kie.api.definition.rule.Query;
@@ -219,7 +220,7 @@ public class MavenDroolsController implements DroolsController {
     }
 
     private void validateText(String text, String errorMessage) {
-        if (text == null || text.isEmpty()) {
+        if (StringUtils.isBlank(text)) {
             throw new IllegalArgumentException(errorMessage);
         }
     }
diff --git a/policy-management/src/main/java/org/onap/policy/drools/features/PolicyControllerFeatureApi.java b/policy-management/src/main/java/org/onap/policy/drools/features/PolicyControllerFeatureApi.java
index f022bf1d..15b48a5c 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/features/PolicyControllerFeatureApi.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/features/PolicyControllerFeatureApi.java
@@ -3,6 +3,7 @@
  * ONAP
  * ================================================================================
  * Copyright (C) 2017-2020 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.
@@ -32,7 +33,7 @@ public interface PolicyControllerFeatureApi extends OrderedService {
      * called before creating a controller with name 'name' and
      * properties 'properties'.
      *
-     * @param name name of the the controller
+     * @param name name of the controller
      * @param properties configuration properties
      *
      * @return a policy controller.   A take over of the creation operation
diff --git a/policy-management/src/main/java/org/onap/policy/drools/persistence/FileSystemPersistence.java b/policy-management/src/main/java/org/onap/policy/drools/persistence/FileSystemPersistence.java
index 9fb76d87..717a6f58 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/persistence/FileSystemPersistence.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/persistence/FileSystemPersistence.java
@@ -35,6 +35,7 @@ import java.util.List;
 import java.util.Properties;
 import java.util.function.BiPredicate;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.ToString;
 import org.onap.policy.drools.properties.DroolsPropertyConstants;
 import org.onap.policy.drools.utils.PropertyUtil;
@@ -151,7 +152,7 @@ public class FileSystemPersistence implements SystemPersistence {
         }
     }
 
-    protected Properties getProperties(Path propertiesPath) {
+    protected Properties getProperties(@NonNull Path propertiesPath) {
         if (!Files.exists(propertiesPath)) {
             throw new IllegalArgumentException("properties for " + propertiesPath + " are not persisted.");
         }
diff --git a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/EventProtocolCoder.java b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/EventProtocolCoder.java
index 88b25255..7cfa5a3a 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/EventProtocolCoder.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/EventProtocolCoder.java
@@ -4,6 +4,7 @@
  * ================================================================================
  * Copyright (C) 2017-2019,2022 AT&T Intellectual Property. All rights reserved.
  * Modifications Copyright(C) 2018 Samsung Electronics Co., Ltd.
+ * 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.
@@ -35,7 +36,7 @@ public interface EventProtocolCoder {
     @Getter
     @Setter
     @AllArgsConstructor
-    public static class CoderFilters {
+    class CoderFilters {
 
         /**
          * coder class.
@@ -54,13 +55,9 @@ public interface EventProtocolCoder {
 
         @Override
         public String toString() {
-            return "CoderFilters [factClass="
-                           + factClass
-                           + ", filter="
-                           + filter
-                           + ", modelClassLoaderHash="
-                           + modelClassLoaderHash
-                           + "]";
+            return "CoderFilters [factClass=" + factClass
+                + ", filter=" + filter
+                + ", modelClassLoaderHash=" + modelClassLoaderHash + "]";
         }
     }
 
diff --git a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GenericEventProtocolCoder.java b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GenericEventProtocolCoder.java
index 0729c706..6fe1648a 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GenericEventProtocolCoder.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GenericEventProtocolCoder.java
@@ -3,6 +3,7 @@
  * ONAP
  * ================================================================================
  * Copyright (C) 2019-2020, 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.
@@ -21,15 +22,19 @@
 package org.onap.policy.drools.protocol.coders;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
+import org.apache.commons.lang3.StringUtils;
 import org.onap.policy.drools.controller.DroolsController;
 import org.onap.policy.drools.controller.DroolsControllerConstants;
 import org.onap.policy.drools.protocol.coders.EventProtocolCoder.CoderFilters;
+import org.onap.policy.drools.system.PolicyDroolsPdpRuntimeException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -43,7 +48,7 @@ abstract class GenericEventProtocolCoder {
     private static final String INVALID_GROUP_ID_MSG = "Invalid group id";
     private static final String INVALID_TOPIC_MSG = "Invalid Topic";
     private static final String UNSUPPORTED_MSG = "Unsupported";
-    private static final String UNSUPPORTED_EX_MSG = "Unsupported:";
+    private static final String UNSUPPORTED_EX_MSG = "Unsupported: ";
     private static final String MISSING_CLASS = "class must be provided";
 
     private static final Logger logger = LoggerFactory.getLogger(GenericEventProtocolCoder.class);
@@ -52,37 +57,26 @@ abstract class GenericEventProtocolCoder {
      * Mapping topic:controller-id -> /<protocol-decoder-toolset/> where protocol-coder-toolset contains
      * a gson-protocol-coder-toolset.
      */
-    protected final HashMap<String, ProtocolCoderToolset> coders =
-            new HashMap<>();
+    protected final HashMap<String, ProtocolCoderToolset> coders = new HashMap<>();
 
     /**
      * Mapping topic + classname -> Protocol Set.
      */
-    protected final HashMap<String, List<ProtocolCoderToolset>>
-            reverseCoders = new HashMap<>();
+    protected final HashMap<String, List<ProtocolCoderToolset>> reverseCoders = new HashMap<>();
 
     /**
      * Index a new coder.
      */
     public void add(EventProtocolParams eventProtocolParams) {
-        if (eventProtocolParams.getGroupId() == null || eventProtocolParams.getGroupId().isEmpty()) {
-            throw new IllegalArgumentException(INVALID_GROUP_ID_MSG);
-        }
 
-        if (eventProtocolParams.getArtifactId() == null || eventProtocolParams.getArtifactId().isEmpty()) {
-            throw new IllegalArgumentException(INVALID_ARTIFACT_ID_MSG);
-        }
+        validateKeyParameters(eventProtocolParams.getGroupId(),
+            eventProtocolParams.getArtifactId(),
+            eventProtocolParams.getTopic());
 
-        if (eventProtocolParams.getTopic() == null || eventProtocolParams.getTopic().isEmpty()) {
-            throw new IllegalArgumentException(INVALID_TOPIC_MSG);
-        }
-
-        if (eventProtocolParams.getEventClass() == null) {
-            throw new IllegalArgumentException("Invalid Event Class");
-        }
+        validateStringParameter(eventProtocolParams.getEventClass(), "Invalid Event Class");
 
         String key = this.codersKey(eventProtocolParams.getGroupId(), eventProtocolParams.getArtifactId(),
-                eventProtocolParams.getTopic());
+            eventProtocolParams.getTopic());
         String reverseKey = this.reverseCodersKey(eventProtocolParams.getTopic(), eventProtocolParams.getEventClass());
 
         synchronized (this) {
@@ -91,22 +85,16 @@ abstract class GenericEventProtocolCoder {
 
                 logger.info("{}: adding coders for existing {}: {}", this, key, toolset);
 
-                toolset
-                        .addCoder(
-                                eventProtocolParams.getEventClass(),
-                                eventProtocolParams.getProtocolFilter(),
-                                eventProtocolParams.getModelClassLoaderHash());
+                toolset.addCoder(
+                    eventProtocolParams.getEventClass(),
+                    eventProtocolParams.getProtocolFilter(),
+                    eventProtocolParams.getModelClassLoaderHash());
 
                 if (!reverseCoders.containsKey(reverseKey)) {
-                    logger.info(
-                            "{}: adding new reverse coders (multiple classes case) for {}:{}: {}",
-                            this,
-                            reverseKey,
-                            key,
-                            toolset);
-
-                    List<ProtocolCoderToolset> reverseMappings =
-                            new ArrayList<>();
+                    logger.info("{}: adding new reverse coders (multiple classes case) for {}:{}: {}",
+                        this, reverseKey, key, toolset);
+
+                    List<ProtocolCoderToolset> reverseMappings = new ArrayList<>();
                     reverseMappings.add(toolset);
                     reverseCoders.put(reverseKey, reverseMappings);
                 }
@@ -128,20 +116,15 @@ abstract class GenericEventProtocolCoder {
             // There is another controller (different group id/artifact id/topic)
             // that shares the class and the topic.
 
-            List<ProtocolCoderToolset> toolsets =
-                    reverseCoders.get(reverseKey);
+            List<ProtocolCoderToolset> toolsets = reverseCoders.get(reverseKey);
             var present = false;
             for (ProtocolCoderToolset parserSet : toolsets) {
-                // just doublecheck
+                // just double check
                 present = parserSet.getControllerId().equals(key);
                 if (present) {
                     /* anomaly */
-                    logger.error(
-                            "{}: unexpected toolset reverse mapping found for {}:{}: {}",
-                            this,
-                            reverseKey,
-                            key,
-                            parserSet);
+                    logger.error("{}: unexpected toolset reverse mapping found for {}:{}: {}",
+                        this, reverseKey, key, parserSet);
                 }
             }
 
@@ -191,17 +174,7 @@ abstract class GenericEventProtocolCoder {
      */
     public void remove(String groupId, String artifactId, String topic) {
 
-        if (groupId == null || groupId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_GROUP_ID_MSG);
-        }
-
-        if (artifactId == null || artifactId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_ARTIFACT_ID_MSG);
-        }
-
-        if (topic == null || topic.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_TOPIC_MSG);
-        }
+        validateKeyParameters(groupId, artifactId, topic);
 
         String key = this.codersKey(groupId, artifactId, topic);
 
@@ -225,23 +198,23 @@ abstract class GenericEventProtocolCoder {
             return;
         }
 
-        List<ProtocolCoderToolset> toolsets =
-                this.reverseCoders.get(reverseKey);
-        Iterator<ProtocolCoderToolset> toolsetsIter =
-                toolsets.iterator();
+        List<ProtocolCoderToolset> toolsets = this.reverseCoders.getOrDefault(reverseKey, Collections.emptyList());
+
+        if (toolsets.isEmpty()) {
+            logger.info("{}: removing reverse mapping for {}: ", this, reverseKey);
+            this.reverseCoders.remove(reverseKey);
+            return;
+        }
+
+        Iterator<ProtocolCoderToolset> toolsetsIter = toolsets.iterator();
+
         while (toolsetsIter.hasNext()) {
             ProtocolCoderToolset toolset = toolsetsIter.next();
             if (toolset.getControllerId().equals(key)) {
-                logger.info(
-                        "{}: removed coder from toolset for {} from reverse mapping", this, reverseKey);
+                logger.info("{}: removed coder from toolset for {} from reverse mapping", this, reverseKey);
                 toolsetsIter.remove();
             }
         }
-
-        if (this.reverseCoders.get(reverseKey).isEmpty()) {
-            logger.info("{}: removing reverse mapping for {}: ", this, reverseKey);
-            this.reverseCoders.remove(reverseKey);
-        }
     }
 
     /**
@@ -250,23 +223,14 @@ abstract class GenericEventProtocolCoder {
      * @param groupId    group id
      * @param artifactId artifact id
      * @param topic      topic
-     * @return true if its is codable
+     * @return true if it's supported to be coded
      */
     public boolean isCodingSupported(String groupId, String artifactId, String topic) {
 
-        if (groupId == null || groupId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_GROUP_ID_MSG);
-        }
-
-        if (artifactId == null || artifactId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_ARTIFACT_ID_MSG);
-        }
-
-        if (topic == null || topic.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_TOPIC_MSG);
-        }
+        validateKeyParameters(groupId, artifactId, topic);
 
         String key = this.codersKey(groupId, artifactId, topic);
+
         synchronized (this) {
             return coders.containsKey(key);
         }
@@ -280,14 +244,14 @@ abstract class GenericEventProtocolCoder {
      * @param topic      topic
      * @param json       json string to convert to object
      * @return the decoded object
-     * @throws IllegalArgumentException      if invalid argument is provided
-     * @throws UnsupportedOperationException if the operation cannot be performed
+     * @throws IllegalArgumentException        if invalid argument is provided
+     * @throws PolicyDroolsPdpRuntimeException if the operation cannot be performed
      */
     public Object decode(String groupId, String artifactId, String topic, String json) {
 
         if (!isCodingSupported(groupId, artifactId, topic)) {
             throw new IllegalArgumentException(
-                    UNSUPPORTED_EX_MSG + codersKey(groupId, artifactId, topic) + " for encoding");
+                UNSUPPORTED_EX_MSG + codersKey(groupId, artifactId, topic) + " for encoding");
         }
 
         String key = this.codersKey(groupId, artifactId, topic);
@@ -321,9 +285,7 @@ abstract class GenericEventProtocolCoder {
             throw new IllegalArgumentException(UNSUPPORTED_EX_MSG + codersKey(groupId, artifactId, topic));
         }
 
-        if (event == null) {
-            throw new IllegalArgumentException("Unsupported topic:" + topic);
-        }
+        validateObjectParameter(event, "Event cannot be null or empty");
 
         // reuse the decoder set, since there must be affinity in the model
         String key = this.codersKey(groupId, artifactId, topic);
@@ -341,25 +303,18 @@ abstract class GenericEventProtocolCoder {
      */
     public String encode(String topic, Object event) {
 
-        if (event == null) {
-            throw new IllegalArgumentException("Invalid encoded class");
-        }
+        validateObjectParameter(event, "Event cannot be null or empty");
 
-        if (topic == null || topic.isEmpty()) {
-            throw new IllegalArgumentException("Invalid topic");
-        }
+        validateStringParameter(topic, INVALID_TOPIC_MSG);
 
         String reverseKey = this.reverseCodersKey(topic, event.getClass().getName());
         if (!this.reverseCoders.containsKey(reverseKey)) {
             throw new IllegalArgumentException("no reverse coder has been found");
         }
 
-        List<ProtocolCoderToolset> toolsets =
-                this.reverseCoders.get(reverseKey);
+        List<ProtocolCoderToolset> toolsets = this.reverseCoders.get(reverseKey);
 
-        String key =
-                codersKey(
-                        toolsets.get(0).getGroupId(), toolsets.get(0).getArtifactId(), topic);
+        String key = codersKey(toolsets.get(0).getGroupId(), toolsets.get(0).getArtifactId(), topic);
         return this.encodeInternal(key, event);
     }
 
@@ -374,13 +329,9 @@ abstract class GenericEventProtocolCoder {
      */
     public String encode(String topic, Object encodedClass, DroolsController droolsController) {
 
-        if (encodedClass == null) {
-            throw new IllegalArgumentException("Invalid encoded class");
-        }
+        validateObjectParameter(encodedClass, "Invalid encoded class");
 
-        if (topic == null || topic.isEmpty()) {
-            throw new IllegalArgumentException("Invalid topic");
-        }
+        validateStringParameter(topic, INVALID_TOPIC_MSG);
 
         String key = codersKey(droolsController.getGroupId(), droolsController.getArtifactId(), topic);
         return this.encodeInternal(key, encodedClass);
@@ -397,31 +348,19 @@ abstract class GenericEventProtocolCoder {
      */
     protected String encodeInternal(String key, Object event) {
 
-        logger.debug("{}: encode for {}: {}", this, key, event);    // NOSONAR
-
-        /*
-         * It seems that sonar declares the previous logging line as a security vulnerability
-         * when logging the topic variable.   The static code analysis indicates that
-         * the path starts in org.onap.policy.drools.server.restful.RestManager::decode(),
-         * but the request is rejected if the topic contains invalid characters (the sonar description
-         * mentions "/r/n/t" characters) all of which are validated against in the checkValidNameInput(topic).
-         * Furthermore production instances are assumed not to have debug enabled, nor the REST telemetry API
-         * should be published externally.  An additional note is that Path URLs containing spaces and newlines
-         * will be rejected earlier in the HTTP protocol libraries (jetty) so an URL of the form
-         * "https://../to\npic" won't even make it here.
-         */
+        logger.debug("{}: encode for {}: {}", this, key, event);
 
         ProtocolCoderToolset coderTools = coders.get(key);
         try {
             String json = coderTools.encode(event);
-            if (json != null && !json.isEmpty()) {
+            if (!StringUtils.isBlank(json)) {
                 return json;
             }
         } catch (Exception e) {
             logger.warn("{}: cannot encode (first) for {}: {}", this, key, event, e);
         }
 
-        throw new UnsupportedOperationException("Cannot decode with gson");
+        throw new UnsupportedOperationException("Cannot encode with gson");
     }
 
     /**
@@ -443,50 +382,37 @@ abstract class GenericEventProtocolCoder {
             return droolsControllers;
         }
 
-        List<ProtocolCoderToolset> toolsets =
-                this.reverseCoders.get(reverseKey);
+        List<ProtocolCoderToolset> toolsets = this.reverseCoders.getOrDefault(reverseKey, Collections.emptyList());
 
         // There must be multiple toolsets associated with <topic,classname> reverseKey
         // case 2 different controllers use the same models and register the same encoder for
         // the same topic.  This is assumed not to occur often but for the purpose of encoding
-        // but there should be no side-effects.  Ownership is crosscheck against classname and
+        // but there should be no side effects.  Ownership is crosscheck against classname and
         // classloader reference.
 
-        if (toolsets == null || toolsets.isEmpty()) {
-            throw new IllegalStateException(
-                    "No Encoders toolsets available for topic "
-                            + topic
-                            + " encoder "
-                            + encodedClass.getClass().getName());
-        }
-
         for (ProtocolCoderToolset encoderSet : toolsets) {
             addToolsetControllers(droolsControllers, encodedClass, encoderSet);
         }
 
         if (droolsControllers.isEmpty()) {
-            throw new IllegalStateException(
-                    "No Encoders toolsets available for "
-                            + topic
-                            + ":"
-                            + encodedClass.getClass().getName());
+            throw new IllegalStateException("No Encoders toolsets available for " + topic + ":"
+                + encodedClass.getClass().getName());
         }
 
         return droolsControllers;
     }
 
     private void addToolsetControllers(List<DroolsController> droolsControllers, Object encodedClass,
-                    ProtocolCoderToolset encoderSet) {
+                                       ProtocolCoderToolset encoderSet) {
         // figure out the right toolset
         String groupId = encoderSet.getGroupId();
         String artifactId = encoderSet.getArtifactId();
         List<CoderFilters> coderFilters = encoderSet.getCoders();
         for (CoderFilters coder : coderFilters) {
             if (coder.getFactClass().equals(encodedClass.getClass().getName())) {
-                var droolsController =
-                                DroolsControllerConstants.getFactory().get(groupId, artifactId, "");
+                var droolsController = DroolsControllerConstants.getFactory().get(groupId, artifactId, "");
                 if (droolsController.ownsCoder(
-                        encodedClass.getClass(), coder.getModelClassLoaderHash())) {
+                    encodedClass.getClass(), coder.getModelClassLoaderHash())) {
                     droolsControllers.add(droolsController);
                 }
             }
@@ -523,19 +449,13 @@ abstract class GenericEventProtocolCoder {
      */
     public List<CoderFilters> getFilters(String groupId, String artifactId) {
 
-        if (groupId == null || groupId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_GROUP_ID_MSG);
-        }
-
-        if (artifactId == null || artifactId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_ARTIFACT_ID_MSG);
-        }
+        validateStringParameter(groupId, INVALID_GROUP_ID_MSG);
+        validateStringParameter(artifactId, INVALID_ARTIFACT_ID_MSG);
 
         String key = this.codersKey(groupId, artifactId, "");
 
         List<CoderFilters> codersFilters = new ArrayList<>();
-        for (Map.Entry<String, ProtocolCoderToolset> entry :
-                coders.entrySet()) {
+        for (Map.Entry<String, ProtocolCoderToolset> entry : coders.entrySet()) {
             if (entry.getKey().startsWith(key)) {
                 codersFilters.addAll(entry.getValue().getCoders());
             }
@@ -555,15 +475,13 @@ abstract class GenericEventProtocolCoder {
      * @throws IllegalArgumentException if invalid input
      */
     public CoderFilters getFilters(
-            String groupId, String artifactId, String topic, String classname) {
+        String groupId, String artifactId, String topic, String classname) {
 
         if (!isCodingSupported(groupId, artifactId, topic)) {
             throw new IllegalArgumentException(UNSUPPORTED_EX_MSG + codersKey(groupId, artifactId, topic));
         }
 
-        if (classname == null || classname.isEmpty()) {
-            throw new IllegalArgumentException("classname must be provided");
-        }
+        validateStringParameter(classname, "classname must be provided");
 
         String key = this.codersKey(groupId, artifactId, topic);
         ProtocolCoderToolset coderTools = coders.get(key);
@@ -580,7 +498,7 @@ abstract class GenericEventProtocolCoder {
      * @throws IllegalArgumentException if invalid input
      */
     public ProtocolCoderToolset getCoders(
-            String groupId, String artifactId, String topic) {
+        String groupId, String artifactId, String topic) {
 
         if (!isCodingSupported(groupId, artifactId, topic)) {
             throw new IllegalArgumentException(UNSUPPORTED_EX_MSG + codersKey(groupId, artifactId, topic));
@@ -598,22 +516,16 @@ abstract class GenericEventProtocolCoder {
      * @return list of coders
      * @throws IllegalArgumentException if invalid input
      */
-    public List<ProtocolCoderToolset> getCoders(
-            String groupId, String artifactId) {
+    public List<ProtocolCoderToolset> getCoders(String groupId, String artifactId) {
 
-        if (groupId == null || groupId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_GROUP_ID_MSG);
-        }
+        validateStringParameter(groupId, INVALID_GROUP_ID_MSG);
 
-        if (artifactId == null || artifactId.isEmpty()) {
-            throw new IllegalArgumentException(INVALID_ARTIFACT_ID_MSG);
-        }
+        validateStringParameter(artifactId, INVALID_ARTIFACT_ID_MSG);
 
         String key = this.codersKey(groupId, artifactId, "");
 
         List<ProtocolCoderToolset> coderToolset = new ArrayList<>();
-        for (Map.Entry<String, ProtocolCoderToolset> entry :
-                coders.entrySet()) {
+        for (Map.Entry<String, ProtocolCoderToolset> entry : coders.entrySet()) {
             if (entry.getKey().startsWith(key)) {
                 coderToolset.add(entry.getValue());
             }
@@ -631,19 +543,12 @@ abstract class GenericEventProtocolCoder {
      */
     public List<CoderFilters> getReverseFilters(String topic, String codedClass) {
 
-        if (topic == null || topic.isEmpty()) {
-            throw new IllegalArgumentException(UNSUPPORTED_MSG);
-        }
+        validateStringParameter(topic, INVALID_TOPIC_MSG);
 
-        if (codedClass == null) {
-            throw new IllegalArgumentException(MISSING_CLASS);
-        }
+        validateStringParameter(codedClass, MISSING_CLASS);
 
         String key = this.reverseCodersKey(topic, codedClass);
-        List<ProtocolCoderToolset> toolsets = this.reverseCoders.get(key);
-        if (toolsets == null) {
-            throw new IllegalArgumentException("No Coder found for " + key);
-        }
+        List<ProtocolCoderToolset> toolsets = this.reverseCoders.getOrDefault(key, Collections.emptyList());
 
         List<CoderFilters> coderFilters = new ArrayList<>();
         for (ProtocolCoderToolset toolset : toolsets) {
@@ -656,79 +561,70 @@ abstract class GenericEventProtocolCoder {
     /**
      * returns group and artifact id of the creator of the encoder.
      *
-     * @param topic topic
-     * @param fact  fact
+     * @param topic        topic
+     * @param encodedClass class encoder
      * @return the drools controller
      */
-    DroolsController getDroolsController(String topic, Object fact) {
-
-        if (topic == null || topic.isEmpty()) {
-            throw new IllegalArgumentException(UNSUPPORTED_MSG);
-        }
-
-        if (fact == null) {
-            throw new IllegalArgumentException(MISSING_CLASS);
-        }
-
-        List<DroolsController> droolsControllers = droolsCreators(topic, fact);
+    DroolsController getDroolsController(String topic, Object encodedClass) {
+        List<DroolsController> droolsControllers = getDroolsControllers(topic, encodedClass);
 
         if (droolsControllers.isEmpty()) {
-            throw new IllegalArgumentException("Invalid Topic: " + topic);
+            throw new IllegalArgumentException(UNSUPPORTED_MSG + " topic " + topic
+                + " and encodedClass " + encodedClass.getClass());
         }
 
-        if (droolsControllers.size() > 1) {
-            logger.warn(
-                    "{}: multiple drools-controller {} for {}:{} ",
-                    this,
-                    droolsControllers,
-                    topic,
-                    fact.getClass().getName());
-            // continue
-        }
         return droolsControllers.get(0);
     }
 
     /**
      * returns group and artifact id of the creator of the encoder.
      *
-     * @param topic topic
-     * @param fact  fact
+     * @param topic        topic
+     * @param encodedClass class encoder
      * @return list of drools controllers
      */
-    List<DroolsController> getDroolsControllers(String topic, Object fact) {
+    List<DroolsController> getDroolsControllers(String topic, Object encodedClass) {
 
-        if (topic == null || topic.isEmpty()) {
-            throw new IllegalArgumentException(UNSUPPORTED_MSG);
-        }
+        validateStringParameter(topic, INVALID_TOPIC_MSG);
 
-        if (fact == null) {
-            throw new IllegalArgumentException(MISSING_CLASS);
-        }
+        validateObjectParameter(encodedClass, MISSING_CLASS);
 
-        List<DroolsController> droolsControllers = droolsCreators(topic, fact);
+        List<DroolsController> droolsControllers = droolsCreators(topic, encodedClass);
         if (droolsControllers.size() > 1) {
             // unexpected
-            logger.warn(
-                    "{}: multiple drools-controller {} for {}:{} ",
-                    this,
-                    droolsControllers,
-                    topic,
-                    fact.getClass().getName());
+            logger.warn("{}: multiple drools-controller {} for {}:{} ",
+                this, droolsControllers, topic, encodedClass.getClass().getName());
             // continue
         }
         return droolsControllers;
     }
 
+    private void validateKeyParameters(String groupId, String artifactId, String topic) {
+        validateStringParameter(groupId, INVALID_GROUP_ID_MSG);
+        validateStringParameter(artifactId, INVALID_ARTIFACT_ID_MSG);
+        validateStringParameter(topic, INVALID_TOPIC_MSG);
+    }
+
+    private static void validateStringParameter(String value, String errorMessage) {
+        if (StringUtils.isBlank(value)) {
+            throw new IllegalArgumentException(errorMessage);
+        }
+    }
+
+    private static void validateObjectParameter(Object object, String errorMessage) {
+        if (Objects.isNull(object)) {
+            throw new IllegalArgumentException(errorMessage);
+        }
+    }
+
     /*
-     * Note: this only logs the KEYSETS, thus lombok ToString annotation is not used.
+     * Note: this only logs the KEY SETS, thus lombok ToString annotation is not used.
      * Otherwise, it results in too much verbosity.
      */
     @Override
     public String toString() {
-        return "GenericEventProtocolCoder [coders="
-                + coders.keySet()
-                + ", reverseCoders="
-                + reverseCoders.keySet()
-                + "]";
+        return "GenericEventProtocolCoder "
+            + "[coders=" + coders.keySet() + ", "
+            + "reverseCoders=" + reverseCoders.keySet() + "]";
     }
 }
diff --git a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GsonProtocolCoderToolset.java b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GsonProtocolCoderToolset.java
index 80844612..18fcb1a3 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GsonProtocolCoderToolset.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/GsonProtocolCoderToolset.java
@@ -3,6 +3,7 @@
  * ONAP
  * ================================================================================
  * Copyright (C) 2019-2022 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.
@@ -62,7 +63,7 @@ class GsonProtocolCoderToolset extends ProtocolCoderToolset {
     public static class GsonUtcAdapter implements JsonSerializer<ZonedDateTime>, JsonDeserializer<ZonedDateTime> {
         @Override
         public ZonedDateTime deserialize(JsonElement element, Type type,
-                JsonDeserializationContext context) {
+                                         JsonDeserializationContext context) {
             try {
                 return ZonedDateTime.parse(element.getAsString(), format);
             } catch (final Exception e) {
@@ -73,7 +74,7 @@ class GsonProtocolCoderToolset extends ProtocolCoderToolset {
 
         @Override
         public JsonElement serialize(ZonedDateTime datetime, Type type,
-                JsonSerializationContext context) {
+                                     JsonSerializationContext context) {
             return new JsonPrimitive(datetime.format(format));
         }
     }
@@ -112,7 +113,7 @@ class GsonProtocolCoderToolset extends ProtocolCoderToolset {
      * Toolset to encode/decode tools associated with a topic.
      *
      * @param eventProtocolParams parameter object for event encoder
-     * @param controllerId controller id
+     * @param controllerId        controller id
      */
     public GsonProtocolCoderToolset(EventProtocolParams eventProtocolParams, String controllerId) {
         super(eventProtocolParams, controllerId);
@@ -145,7 +146,7 @@ class GsonProtocolCoderToolset extends ProtocolCoderToolset {
     public Object decode(String json) {
 
         final var droolsController =
-                        DroolsControllerConstants.getFactory().get(this.groupId, this.artifactId, "");
+            DroolsControllerConstants.getFactory().get(this.groupId, this.artifactId, "");
         if (droolsController == null) {
             logger.warn("{}: no drools-controller to process {}", this, json);
             throw new IllegalStateException("no drools-controller to process event");
@@ -163,35 +164,36 @@ class GsonProtocolCoderToolset extends ProtocolCoderToolset {
             if (decoderClass == null) {
                 logger.warn(CANNOT_FETCH_CLASS, this, decoderFilter.getFactClass());
                 throw new IllegalStateException(
-                        FETCH_CLASS_EX_MSG + decoderFilter.getFactClass());
+                    FETCH_CLASS_EX_MSG + decoderFilter.getFactClass());
             }
         } catch (final Exception e) {
             logger.warn(CANNOT_FETCH_CLASS, this, decoderFilter.getFactClass());
             throw new UnsupportedOperationException(
-                    FETCH_CLASS_EX_MSG + decoderFilter.getFactClass(), e);
+                FETCH_CLASS_EX_MSG + decoderFilter.getFactClass(), e);
         }
 
         if (this.customCoder != null) {
             try {
                 final var gsonClassContainer =
-                        droolsController.fetchModelClass(this.customCoder.getClassContainer());
+                    droolsController.fetchModelClass(this.customCoder.getClassContainer());
                 final var gsonField = gsonClassContainer.getField(this.customCoder.staticCoderField);
                 final var gsonObject = gsonField.get(null);
                 final var fromJsonMethod = gsonObject.getClass().getDeclaredMethod("fromJson",
-                        String.class, Class.class);
+                    String.class, Class.class);
                 return fromJsonMethod.invoke(gsonObject, json, decoderClass);
             } catch (final Exception e) {
                 logger.warn(CANNOT_FETCH_CLASS, this, decoderFilter.getFactClass());
-                throw new UnsupportedOperationException(
-                        FETCH_CLASS_EX_MSG + decoderFilter.getFactClass(), e);
+                throw new UnsupportedOperationException("cannot decode with customCoder: "
+                    + customCoder.getClassContainer()
+                    + " using application class " + decoderFilter.getFactClass(), e);
             }
         } else {
             try {
-                return this.decoder.fromJson(json, decoderClass);
+                return this.getDecoder().fromJson(json, decoderClass);
             } catch (final Exception e) {
                 logger.warn("{} cannot decode {} into {}", this, json, decoderClass.getName());
                 throw new UnsupportedOperationException(
-                        "cannot decode into " + decoderFilter.getFactClass(), e);
+                    "cannot decode into " + decoderFilter.getFactClass(), e);
             }
         }
     }
@@ -205,21 +207,20 @@ class GsonProtocolCoderToolset extends ProtocolCoderToolset {
         if (this.customCoder != null) {
             try {
                 final var droolsController =
-                                DroolsControllerConstants.getFactory().get(this.groupId, this.artifactId, null);
+                    DroolsControllerConstants.getFactory().get(this.groupId, this.artifactId, null);
                 final Class<?> gsonClassContainer =
-                        droolsController.fetchModelClass(this.customCoder.getClassContainer());
+                    droolsController.fetchModelClass(this.customCoder.getClassContainer());
                 final var gsonField = gsonClassContainer.getField(this.customCoder.staticCoderField);
                 final var gsonObject = gsonField.get(null);
-                final var toJsonMethod =
-                        gsonObject.getClass().getDeclaredMethod("toJson", Object.class);
+                final var toJsonMethod = gsonObject.getClass().getDeclaredMethod("toJson", Object.class);
                 return (String) toJsonMethod.invoke(gsonObject, event);
             } catch (final Exception e) {
                 logger.warn("{} cannot custom-encode {}", this, event);
-                throw new UnsupportedOperationException("event cannot be encoded", e);
+                throw new UnsupportedOperationException("event cannot be custom encoded", e);
             }
         } else {
             try {
-                return this.encoder.toJson(event);
+                return this.getEncoder().toJson(event);
             } catch (final Exception e) {
                 logger.warn("{} cannot encode {}", this, event);
                 throw new UnsupportedOperationException("event cannot be encoded", e);
diff --git a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/MultiplexorEventProtocolCoder.java b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/MultiplexorEventProtocolCoder.java
index 3fea6821..cfbf2e4f 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/MultiplexorEventProtocolCoder.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/MultiplexorEventProtocolCoder.java
@@ -3,6 +3,7 @@
  * ONAP
  * ================================================================================
  * Copyright (C) 2019, 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.
@@ -20,7 +21,6 @@
 
 package org.onap.policy.drools.protocol.coders;
 
-import java.util.ArrayList;
 import java.util.List;
 import lombok.ToString;
 import org.onap.policy.drools.controller.DroolsController;
@@ -126,19 +126,7 @@ class MultiplexorEventProtocolCoder implements EventProtocolCoder {
      */
     @Override
     public Object decode(String groupId, String artifactId, String topic, String json) {
-        logger.debug("{}: decode {}:{}:{}:{}", this, groupId, artifactId, topic, json);  // NOSONAR
-
-        /*
-         * It seems that sonar declares the previous logging line as a security vulnerability
-         * when logging the topic variable.   The static code analysis indicates that
-         * the path starts in org.onap.policy.drools.server.restful.RestManager::decode(),
-         * but the request is rejected if the topic contains invalid characters (the sonar description
-         * mentions "/r/n/t" characters) which are validated against in the checkValidNameInput(topic).
-         * Furthermore production instances are assumed not to have debug enabled, nor the REST telemetry API
-         * should be published externally.  An additional note is that Path URLs containing spaces and newlines
-         * will be failed earlier at the HTTP protocol libraries (jetty, etc ..) so an URL of the form
-         * "https://../to\npic" won't even make it here.
-         */
+        logger.debug("{}: decode {}:{}:{}:{}", this, groupId, artifactId, topic, json);
         return this.decoders.decode(groupId, artifactId, topic, json);
     }
 
@@ -156,13 +144,7 @@ class MultiplexorEventProtocolCoder implements EventProtocolCoder {
      */
     @Override
     public String encode(String topic, Object event) {
-        logger.debug("{}: encode {}:{}", this, topic, event);  // NOSONAR
-
-        /*
-         * See explanation for decode(String groupId, String artifactId, String topic, String json).
-         * The same applies here as it is called from
-         * org.onap.policy.drools.server.restful.RestManager::encode(),
-         */
+        logger.debug("{}: encode {}:{}", this, topic, event);
         return this.encoders.encode(topic, event);
     }
 
@@ -187,8 +169,7 @@ class MultiplexorEventProtocolCoder implements EventProtocolCoder {
      * {@inheritDoc}.
      */
     @Override
-    public CoderFilters getDecoderFilters(
-            String groupId, String artifactId, String topic, String classname) {
+    public CoderFilters getDecoderFilters(String groupId, String artifactId, String topic, String classname) {
         return this.decoders.getFilters(groupId, artifactId, topic, classname);
     }
 
@@ -205,18 +186,11 @@ class MultiplexorEventProtocolCoder implements EventProtocolCoder {
      */
     @Override
     public ProtocolCoderToolset getDecoders(String groupId, String artifactId, String topic) {
-        ProtocolCoderToolset decoderToolsets =
-                this.decoders.getCoders(groupId, artifactId, topic);
-        if (decoderToolsets == null) {
-            throw new IllegalArgumentException(
-                    "Decoders not found for " + groupId + ":" + artifactId + ":" + topic);
-        }
-
-        return decoderToolsets;
+        return this.decoders.getCoders(groupId, artifactId, topic);
     }
 
     /**
-     * get all deocders by maven coordinates and topic.
+     * get all decoders by maven coordinates and topic.
      *
      * @param groupId    group id
      * @param artifactId artifact id
@@ -225,14 +199,7 @@ class MultiplexorEventProtocolCoder implements EventProtocolCoder {
      */
     @Override
     public List<ProtocolCoderToolset> getDecoders(String groupId, String artifactId) {
-
-        List<ProtocolCoderToolset> decoderToolsets =
-                this.decoders.getCoders(groupId, artifactId);
-        if (decoderToolsets == null) {
-            throw new IllegalArgumentException("Decoders not found for " + groupId + ":" + artifactId);
-        }
-
-        return new ArrayList<>(decoderToolsets);
+        return this.decoders.getCoders(groupId, artifactId);
     }
 
     /**
diff --git a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/ProtocolCoderToolset.java b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/ProtocolCoderToolset.java
index 277c4ed3..5cd68709 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/ProtocolCoderToolset.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/ProtocolCoderToolset.java
@@ -4,6 +4,7 @@
  * ================================================================================
  * Copyright (C) 2017-2022 AT&T Intellectual Property. All rights reserved.
  * Modifications Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ * 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.
@@ -26,6 +27,7 @@ import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import lombok.Getter;
 import lombok.Setter;
+import org.apache.commons.lang3.StringUtils;
 import org.onap.policy.drools.protocol.coders.EventProtocolCoder.CoderFilters;
 import org.onap.policy.drools.protocol.coders.TopicCoderFilterConfiguration.CustomCoder;
 import org.slf4j.Logger;
@@ -82,7 +84,7 @@ public abstract class ProtocolCoderToolset {
      */
     protected ProtocolCoderToolset(EventProtocolParams eventProtocolParams, String controllerId) {
 
-        if (eventProtocolParams == null || controllerId == null) {
+        if (eventProtocolParams == null || StringUtils.isBlank(controllerId)) {
             throw new IllegalArgumentException("Invalid input");
         }
 
@@ -104,7 +106,7 @@ public abstract class ProtocolCoderToolset {
      * @return the decoder filters or null if not found
      */
     public CoderFilters getCoder(String classname) {
-        if (classname == null || classname.isEmpty()) {
+        if (StringUtils.isBlank(classname)) {
             throw new IllegalArgumentException("no classname provided");
         }
 
@@ -132,7 +134,7 @@ public abstract class ProtocolCoderToolset {
      * @param filter filter
      */
     public void addCoder(String eventClass, JsonProtocolFilter filter, int modelClassLoaderHash) {
-        if (eventClass == null || eventClass.isEmpty()) {
+        if (StringUtils.isBlank(eventClass)) {
             throw new IllegalArgumentException("no event class provided");
         }
 
@@ -152,7 +154,7 @@ public abstract class ProtocolCoderToolset {
      * @param eventClass event class
      */
     public void removeCoders(String eventClass) {
-        if (eventClass == null || eventClass.isEmpty()) {
+        if (StringUtils.isBlank(eventClass)) {
             throw new IllegalArgumentException("no event class provided");
         }
 
diff --git a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/TopicCoderFilterConfiguration.java b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/TopicCoderFilterConfiguration.java
index 4dd132b9..69bc0527 100644
--- a/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/TopicCoderFilterConfiguration.java
+++ b/policy-management/src/main/java/org/onap/policy/drools/protocol/coders/TopicCoderFilterConfiguration.java
@@ -3,6 +3,7 @@
  * policy-management
  * ================================================================================
  * Copyright (C) 2017-2021 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.
@@ -25,6 +26,7 @@ import lombok.AllArgsConstructor;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
+import org.apache.commons.lang3.StringUtils;
 
 @Getter
 @ToString
@@ -51,19 +53,21 @@ public class TopicCoderFilterConfiguration {
          * @param rawCustomCoder with format: &lt;class-containing-custom-coder&gt;,&lt;static-coder-field&gt.
          */
         protected CustomCoder(String rawCustomCoder) {
-            if (rawCustomCoder != null && !rawCustomCoder.isEmpty()) {
-
-                this.classContainer = rawCustomCoder.substring(0, rawCustomCoder.indexOf(','));
-                if (this.classContainer == null || this.classContainer.isEmpty()) {
-                    throw new IllegalArgumentException(
-                            "No classname to create CustomCoder cannot be created");
-                }
-
-                this.staticCoderField = rawCustomCoder.substring(rawCustomCoder.indexOf(',') + 1);
-                if (this.staticCoderField == null || this.staticCoderField.isEmpty()) {
-                    throw new IllegalArgumentException(
-                            "No staticCoderField to create CustomCoder cannot be created for class " + classContainer);
-                }
+            if (StringUtils.isBlank(rawCustomCoder)) {
+                throw new IllegalArgumentException("Constructor argument cannot be empty. "
+                    + "Use format \"customCoderClass,staticCoderField\"");
+            }
+
+            this.classContainer = rawCustomCoder.substring(0, rawCustomCoder.indexOf(','));
+            if (StringUtils.isBlank(this.classContainer)) {
+                throw new IllegalArgumentException(
+                    "No classname to create CustomCoder cannot be created");
+            }
+
+            this.staticCoderField = rawCustomCoder.substring(rawCustomCoder.indexOf(',') + 1);
+            if (StringUtils.isBlank(this.staticCoderField)) {
+                throw new IllegalArgumentException(
+                    "No staticCoderField to create CustomCoder cannot be created for class " + classContainer);
             }
         }
 
@@ -74,11 +78,11 @@ public class TopicCoderFilterConfiguration {
          * @param staticCoderField static coder field
          */
         protected CustomCoder(String className, String staticCoderField) {
-            if (className == null || className.isEmpty()) {
+            if (StringUtils.isBlank(className)) {
                 throw new IllegalArgumentException("No classname to create CustomCoder cannot be created");
             }
 
-            if (staticCoderField == null || staticCoderField.isEmpty()) {
+            if (StringUtils.isBlank(staticCoderField)) {
                 throw new IllegalArgumentException(
                         "No staticCoderField to create CustomCoder cannot be created for class " + className);
             }