Convert Intermediary Participant to Spring and refactor Participants

Issue-ID: POLICY-3370
Change-Id: I1541fc47b35c91f9ec86ab768bc3cec2cd78647c
Signed-off-by: FrancescoFioraEst <francesco.fiora@est.tech>

14 files changed, 257 insertions, 295 deletions

diff --git a/participant/participant-intermediary/pom.xml b/participant/participant-intermediary/pom.xml
index aac80a4a2..9f754148e 100644
--- a/participant/participant-intermediary/pom.xml
+++ b/participant/participant-intermediary/pom.xml
@@ -33,4 +33,11 @@
     <description>Common intermediary library for managing DMaaP participant messaging and holding participant and control
      loop state</description>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webmvc</artifactId>
+        </dependency>
+    </dependencies>
+
 </project>
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java
index adc9c2393..a87299bdc 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java
@@ -31,25 +31,12 @@ import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoop
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantStatistics;
-import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
-import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
 
 /**
  * This interface is used by participant implementations to use the participant intermediary.
  */
 public interface ParticipantIntermediaryApi {
-    /**
-     * Initialise the participant intermediary.
-     *
-     * @param parameters the parameters for the intermediary
-     */
-    void init(ParticipantIntermediaryParameters parameters);
-
-    /**
-     * Close the intermediary.
-     */
-    void close();
 
     /**
      * Register a listener for control loop elements that are mediated by the intermediary.
@@ -128,12 +115,4 @@ public interface ParticipantIntermediaryApi {
      */
     void updateControlLoopElementStatistics(UUID id, ClElementStatistics elementStatistics);
 
-    /**
-     * Return participantHandler, This will not be used in real world, but for junits,
-     * if participantHandler is not returned, there is no way to test state change messages
-     * without dmaap simulator.
-     *
-     * @return the participant handler
-     */
-    ParticipantHandler getParticipantHandler();
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java
index 839088d72..838f47544 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java
@@ -35,45 +35,41 @@ import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantStatistics;
 import org.onap.policy.clamp.controlloop.participant.intermediary.api.ControlLoopElementListener;
 import org.onap.policy.clamp.controlloop.participant.intermediary.api.ParticipantIntermediaryApi;
-import org.onap.policy.clamp.controlloop.participant.intermediary.handler.IntermediaryActivator;
 import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
-import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
+import org.springframework.stereotype.Component;
 
 /**
  * This class is api implementation used by participant intermediary.
  */
+@Component
 public class ParticipantIntermediaryApiImpl implements ParticipantIntermediaryApi {
 
-    // The activator for the participant intermediary
-    private IntermediaryActivator activator;
+    // The handler for the participant intermediary
+    private ParticipantHandler participantHandler;
 
-    @Override
-    public void init(ParticipantIntermediaryParameters parameters) {
-        activator = new IntermediaryActivator(parameters);
-
-        activator.start();
-    }
-
-    @Override
-    public void close() {
-        activator.shutdown();
+    /**
+     * Constructor.
+     *
+     * @param participantHandler ParticipantHandler
+     */
+    public ParticipantIntermediaryApiImpl(ParticipantHandler participantHandler) {
+        this.participantHandler = participantHandler;
     }
 
     @Override
     public void registerControlLoopElementListener(ControlLoopElementListener controlLoopElementListener) {
-        activator.getParticipantHandler().getControlLoopHandler()
-                .registerControlLoopElementListener(controlLoopElementListener);
+        participantHandler.getControlLoopHandler().registerControlLoopElementListener(controlLoopElementListener);
     }
 
     @Override
     public List<Participant> getParticipants(String name, String version) {
-        return List.of(activator.getParticipantHandler().getParticipant(name, version));
+        return List.of(participantHandler.getParticipant(name, version));
     }
 
     @Override
     public Participant updateParticipantState(ToscaConceptIdentifier definition, ParticipantState state) {
-        return activator.getParticipantHandler().updateParticipantState(definition, state);
+        return participantHandler.updateParticipantState(definition, state);
     }
 
     @Override
@@ -83,13 +79,13 @@ public class ParticipantIntermediaryApiImpl implements ParticipantIntermediaryAp
 
     @Override
     public ControlLoops getControlLoops(String name, String version) {
-        return activator.getParticipantHandler().getControlLoopHandler().getControlLoops();
+        return participantHandler.getControlLoopHandler().getControlLoops();
     }
 
     @Override
     public Map<UUID, ControlLoopElement> getControlLoopElements(String name, String version) {
-        List<ControlLoop> controlLoops = activator.getParticipantHandler()
-                .getControlLoopHandler().getControlLoops().getControlLoopList();
+        List<ControlLoop> controlLoops =
+                participantHandler.getControlLoopHandler().getControlLoops().getControlLoopList();
 
         for (ControlLoop controlLoop : controlLoops) {
             if (name.equals(controlLoop.getDefinition().getName())) {
@@ -101,8 +97,8 @@ public class ParticipantIntermediaryApiImpl implements ParticipantIntermediaryAp
 
     @Override
     public ControlLoopElement getControlLoopElement(UUID id) {
-        List<ControlLoop> controlLoops = activator.getParticipantHandler()
-                .getControlLoopHandler().getControlLoops().getControlLoopList();
+        List<ControlLoop> controlLoops =
+                participantHandler.getControlLoopHandler().getControlLoops().getControlLoopList();
 
         for (ControlLoop controlLoop : controlLoops) {
             ControlLoopElement clElement = controlLoop.getElements().get(id);
@@ -116,18 +112,11 @@ public class ParticipantIntermediaryApiImpl implements ParticipantIntermediaryAp
     @Override
     public ControlLoopElement updateControlLoopElementState(UUID id, ControlLoopOrderedState currentState,
             ControlLoopState newState) {
-        return activator.getParticipantHandler().getControlLoopHandler()
-                .updateControlLoopElementState(id, currentState, newState);
+        return participantHandler.getControlLoopHandler().updateControlLoopElementState(id, currentState, newState);
     }
 
     @Override
     public void updateControlLoopElementStatistics(UUID id, ClElementStatistics elementStatistics) {
-        activator.getParticipantHandler().getControlLoopHandler()
-        .updateControlLoopElementStatistics(id, elementStatistics);
-    }
-
-    @Override
-    public ParticipantHandler getParticipantHandler() {
-        return activator.getParticipantHandler();
+        participantHandler.getControlLoopHandler().updateControlLoopElementStatistics(id, elementStatistics);
     }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopStateChangeListener.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopStateChangeListener.java
index 50b8b9cdc..e46c6db1b 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopStateChangeListener.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopStateChangeListener.java
@@ -20,23 +20,15 @@
 
 package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
 
-import java.io.Closeable;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopStateChange;
 import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
-import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
-import org.onap.policy.common.endpoints.listeners.ScoListener;
-import org.onap.policy.common.utils.coder.StandardCoderObject;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
 
 /**
  * Listener for Participant State Change messages sent by CLAMP.
  */
-public class ControlLoopStateChangeListener extends ScoListener<ParticipantControlLoopStateChange>
-        implements Closeable {
-    private static final Logger LOGGER = LoggerFactory.getLogger(ControlLoopStateChangeListener.class);
-
-    private final ParticipantHandler participantHandler;
+@Component
+public class ControlLoopStateChangeListener extends ParticipantListener<ParticipantControlLoopStateChange> {
 
     /**
      * Constructs the object.
@@ -44,25 +36,7 @@ public class ControlLoopStateChangeListener extends ScoListener<ParticipantContr
      * @param participantHandler the handler for managing the state of the participant
      */
     public ControlLoopStateChangeListener(final ParticipantHandler participantHandler) {
-        super(ParticipantControlLoopStateChange.class);
-        this.participantHandler = participantHandler;
-    }
-
-    @Override
-    public void onTopicEvent(final CommInfrastructure infra, final String topic, final StandardCoderObject sco,
-            final ParticipantControlLoopStateChange controlLoopStateChangeMsg) {
-        LOGGER.debug("Control Loop State Change received from CLAMP - {}", controlLoopStateChangeMsg);
-
-        if (participantHandler.canHandle(controlLoopStateChangeMsg)) {
-            LOGGER.debug("Message for this participant");
-            participantHandler.getControlLoopHandler().handleControlLoopStateChange(controlLoopStateChangeMsg);
-        } else {
-            LOGGER.debug("Message not for this participant");
-        }
-    }
-
-    @Override
-    public void close() {
-        // No explicit action on this class
+        super(ParticipantControlLoopStateChange.class, participantHandler,
+                participantHandler::handleControlLoopStateChange);
     }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopUpdateListener.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopUpdateListener.java
index ab2437c1c..d15643e0f 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopUpdateListener.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopUpdateListener.java
@@ -20,22 +20,15 @@
 
 package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
 
-import java.io.Closeable;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
 import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
-import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
-import org.onap.policy.common.endpoints.listeners.ScoListener;
-import org.onap.policy.common.utils.coder.StandardCoderObject;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
 
 /**
  * Listener for Control Loop Update messages sent by CLAMP.
  */
-public class ControlLoopUpdateListener extends ScoListener<ParticipantControlLoopUpdate> implements Closeable {
-    private static final Logger LOGGER = LoggerFactory.getLogger(ControlLoopUpdateListener.class);
-
-    private final ParticipantHandler participantHandler;
+@Component
+public class ControlLoopUpdateListener extends ParticipantListener<ParticipantControlLoopUpdate> {
 
     /**
      * Constructs the object.
@@ -43,25 +36,6 @@ public class ControlLoopUpdateListener extends ScoListener<ParticipantControlLoo
      * @param participantHandler the handler for managing the state of the participant
      */
     public ControlLoopUpdateListener(final ParticipantHandler participantHandler) {
-        super(ParticipantControlLoopUpdate.class);
-        this.participantHandler = participantHandler;
-    }
-
-    @Override
-    public void onTopicEvent(final CommInfrastructure infra, final String topic, final StandardCoderObject sco,
-            final ParticipantControlLoopUpdate participantControlLoopUpdateMsg) {
-        LOGGER.debug("Control Loop update received from CLAMP - {}", participantControlLoopUpdateMsg);
-
-        if (participantHandler.canHandle(participantControlLoopUpdateMsg)) {
-            LOGGER.debug("Message for this participant");
-            participantHandler.getControlLoopHandler().handleControlLoopUpdate(participantControlLoopUpdateMsg);
-        } else {
-            LOGGER.debug("Message not for this participant");
-        }
-    }
-
-    @Override
-    public void close() {
-        // No explicit action on this class
+        super(ParticipantControlLoopUpdate.class, participantHandler, participantHandler::handleControlLoopUpdate);
     }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantHealthCheckListener.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantHealthCheckListener.java
index e0e6be329..15f5140eb 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantHealthCheckListener.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantHealthCheckListener.java
@@ -20,22 +20,15 @@
 
 package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
 
-import java.io.Closeable;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantHealthCheck;
 import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
-import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
-import org.onap.policy.common.endpoints.listeners.ScoListener;
-import org.onap.policy.common.utils.coder.StandardCoderObject;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
 
 /**
  * Listener for Participant health status messages sent by CLAMP.
  */
-public class ParticipantHealthCheckListener extends ScoListener<ParticipantHealthCheck> implements Closeable {
-    private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantHealthCheckListener.class);
-
-    private final ParticipantHandler participantHandler;
+@Component
+public class ParticipantHealthCheckListener extends ParticipantListener<ParticipantHealthCheck> {
 
     /**
      * Constructs the object.
@@ -43,27 +36,6 @@ public class ParticipantHealthCheckListener extends ScoListener<ParticipantHealt
      * @param participantHandler the handler for managing the state and health of the participant
      */
     public ParticipantHealthCheckListener(final ParticipantHandler participantHandler) {
-        super(ParticipantHealthCheck.class);
-        this.participantHandler = participantHandler;
-    }
-
-    @Override
-    public void onTopicEvent(final CommInfrastructure infra, final String topic, final StandardCoderObject sco,
-            final ParticipantHealthCheck participantHealthCheckMsg) {
-        LOGGER.debug("Participant Health Check message received from CLAMP - {}", participantHealthCheckMsg);
-
-
-        if (participantHandler.canHandle(participantHealthCheckMsg)) {
-            LOGGER.debug("Message for this participant");
-            participantHandler.handleParticipantHealthCheck(participantHealthCheckMsg);
-        } else {
-            LOGGER.debug("Message not for this participant");
-        }
-
-    }
-
-    @Override
-    public void close() {
-        // No explicit action on this class
+        super(ParticipantHealthCheck.class, participantHandler, participantHandler::handleParticipantHealthCheck);
     }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantListener.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantListener.java
new file mode 100644
index 000000000..c6ad900b3
--- /dev/null
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantListener.java
@@ -0,0 +1,57 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 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.clamp.controlloop.participant.intermediary.comm;
+
+import java.util.function.Consumer;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantMessage;
+import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.common.endpoints.listeners.ScoListener;
+import org.onap.policy.common.utils.coder.StandardCoderObject;
+
+/**
+ * Abstract Listener for Participant messages sent by CLAMP.
+ */
+public abstract class ParticipantListener<T extends ParticipantMessage> extends ScoListener<T> {
+
+    private final ParticipantHandler participantHandler;
+    private final Consumer<T> consumer;
+
+    /**
+     * Constructs the object.
+     *
+     * @param clazz class of message this handles
+     * @param participantHandler ParticipantHandler
+     * @param consumer function that handles the message
+     */
+    protected ParticipantListener(Class<T> clazz, ParticipantHandler participantHandler, Consumer<T> consumer) {
+        super(clazz);
+        this.participantHandler = participantHandler;
+        this.consumer = consumer;
+    }
+
+    @Override
+    public void onTopicEvent(CommInfrastructure infra, String topic, StandardCoderObject sco, T message) {
+        if (participantHandler.appliesTo(message)) {
+            consumer.accept(message);
+        }
+    }
+}
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStateChangeListener.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStateChangeListener.java
index c1a8b5b4a..ec6548a7c 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStateChangeListener.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStateChangeListener.java
@@ -20,23 +20,16 @@
 
 package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
 
-import java.io.Closeable;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStateChange;
 import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
-import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
-import org.onap.policy.common.endpoints.listeners.ScoListener;
-import org.onap.policy.common.utils.coder.StandardCoderObject;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
 
 /**
  * Listener for Participant State Change messages sent by CLAMP.
  *
  */
-public class ParticipantStateChangeListener extends ScoListener<ParticipantStateChange> implements Closeable {
-    private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantStateChangeListener.class);
-
-    private final ParticipantHandler participantHandler;
+@Component
+public class ParticipantStateChangeListener extends ParticipantListener<ParticipantStateChange> {
 
     /**
      * Constructs the object.
@@ -44,25 +37,6 @@ public class ParticipantStateChangeListener extends ScoListener<ParticipantState
      * @param participantHandler the handler for managing the state of the participant
      */
     public ParticipantStateChangeListener(final ParticipantHandler participantHandler) {
-        super(ParticipantStateChange.class);
-        this.participantHandler = participantHandler;
-    }
-
-    @Override
-    public void onTopicEvent(final CommInfrastructure infra, final String topic, final StandardCoderObject sco,
-            final ParticipantStateChange participantStateChangeMsg) {
-        LOGGER.debug("Participant State Change received from CLAMP - {}", participantStateChangeMsg);
-
-        if (participantHandler.canHandle(participantStateChangeMsg)) {
-            LOGGER.debug("Message for this participant");
-            participantHandler.handleParticipantStateChange(participantStateChangeMsg);
-        } else {
-            LOGGER.debug("Message not for this participant");
-        }
-    }
-
-    @Override
-    public void close() {
-        // No explicit action on this class
+        super(ParticipantStateChange.class, participantHandler, participantHandler::handleParticipantStateChange);
     }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStatusPublisher.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStatusPublisher.java
index bc53b4e9d..78b998453 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStatusPublisher.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStatusPublisher.java
@@ -20,7 +20,6 @@
 
 package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
 
-import java.io.Closeable;
 import java.util.List;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStatus;
 import org.onap.policy.common.endpoints.event.comm.TopicSink;
@@ -32,7 +31,7 @@ import org.slf4j.LoggerFactory;
  * This class is used to send Participant Status messages to clamp using TopicSinkClient.
  *
  */
-public class ParticipantStatusPublisher implements Closeable {
+public class ParticipantStatusPublisher {
     private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantStatusPublisher.class);
 
     private final TopicSinkClient topicSinkClient;
@@ -55,9 +54,4 @@ public class ParticipantStatusPublisher implements Closeable {
         topicSinkClient.send(participantStatus);
         LOGGER.debug("Sent Participant Status message to CLAMP - {}", participantStatus);
     }
-
-    @Override
-    public void close() {
-        // No explicit action on this class
-    }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/config/BeanFactory.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/config/BeanFactory.java
new file mode 100644
index 000000000..dc7d87eec
--- /dev/null
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/config/BeanFactory.java
@@ -0,0 +1,55 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 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.clamp.controlloop.participant.intermediary.config;
+
+import java.util.List;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantStatusPublisher;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantParameters;
+import org.onap.policy.common.endpoints.event.comm.TopicEndpointManager;
+import org.onap.policy.common.endpoints.event.comm.TopicSink;
+import org.onap.policy.common.endpoints.listeners.MessageTypeDispatcher;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class BeanFactory {
+
+    // Name of the message type for messages on topics
+    private static final String[] MSG_TYPE_NAMES = {"messageType"};
+
+    /**
+     * create ParticipantStatusPublisher.
+     *
+     * @param parameters the ParticipantParameters
+     * @return ParticipantStatusPublisher
+     */
+    @Bean
+    public ParticipantStatusPublisher publisher(final ParticipantParameters parameters) {
+        List<TopicSink> topicSinks = TopicEndpointManager.getManager()
+                .addTopicSinks(parameters.getIntermediaryParameters().getClampControlLoopTopics().getTopicSinks());
+        return new ParticipantStatusPublisher(topicSinks);
+    }
+
+    @Bean
+    public MessageTypeDispatcher msgDispatcher() {
+        return new MessageTypeDispatcher(MSG_TYPE_NAMES);
+    }
+}
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ControlLoopHandler.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ControlLoopHandler.java
index 3eebd177f..50048ffc2 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ControlLoopHandler.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ControlLoopHandler.java
@@ -20,7 +20,6 @@
 
 package org.onap.policy.clamp.controlloop.participant.intermediary.handler;
 
-import java.io.Closeable;
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -51,7 +50,7 @@ import org.slf4j.LoggerFactory;
  * This class is responsible for managing the state of all control loops in the participant.
  */
 @NoArgsConstructor
-public class ControlLoopHandler implements Closeable {
+public class ControlLoopHandler {
     private static final Logger LOGGER = LoggerFactory.getLogger(ControlLoopHandler.class);
 
     private ToscaConceptIdentifier participantType = null;
@@ -77,11 +76,6 @@ public class ControlLoopHandler implements Closeable {
         this.messageSender = messageSender;
     }
 
-    @Override
-    public void close() {
-        // No explicit action on this class
-    }
-
     public void registerControlLoopElementListener(ControlLoopElementListener listener) {
         listeners.add(listener);
     }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/IntermediaryActivator.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/IntermediaryActivator.java
index 3eae27267..2d789d40d 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/IntermediaryActivator.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/IntermediaryActivator.java
@@ -20,125 +20,100 @@
 
 package org.onap.policy.clamp.controlloop.participant.intermediary.handler;
 
+import java.io.Closeable;
+import java.io.IOException;
 import java.util.List;
-import java.util.concurrent.atomic.AtomicReference;
-import javax.ws.rs.core.Response.Status;
-import lombok.Getter;
-import org.onap.policy.clamp.controlloop.common.exception.ControlLoopRuntimeException;
-import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopStateChange;
-import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
-import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantHealthCheck;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantMessageType;
-import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStateChange;
 import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ControlLoopStateChangeListener;
 import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ControlLoopUpdateListener;
 import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantHealthCheckListener;
 import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantStateChangeListener;
-import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantStatusPublisher;
-import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantParameters;
 import org.onap.policy.common.endpoints.event.comm.TopicEndpointManager;
-import org.onap.policy.common.endpoints.event.comm.TopicSink;
 import org.onap.policy.common.endpoints.event.comm.TopicSource;
 import org.onap.policy.common.endpoints.listeners.MessageTypeDispatcher;
-import org.onap.policy.common.endpoints.listeners.ScoListener;
 import org.onap.policy.common.utils.services.ServiceManagerContainer;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.event.ContextClosedEvent;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
 
 /**
  * This class activates the Participant Intermediary together with all its handlers.
  */
-public class IntermediaryActivator extends ServiceManagerContainer {
-    // Name of the message type for messages on topics
-    private static final String[] MSG_TYPE_NAMES = {"messageType"};
+@Component
+public class IntermediaryActivator extends ServiceManagerContainer implements Closeable {
 
-    @Getter
-    private final ParticipantIntermediaryParameters parameters;
+    private final ApplicationContext applicationContext;
 
     // Topics from which the participant receives and to which the participant sends messages
-    private List<TopicSink> topicSinks;
     private List<TopicSource> topicSources;
 
-    // The participant handler for this intermediary
-    final AtomicReference<ParticipantHandler> participantHandler = new AtomicReference<>();
-
-    /**
-     * Listens for messages on the topic, decodes them into a message, and then dispatches them.
-     */
-    private final MessageTypeDispatcher msgDispatcher;
-
     /**
      * Instantiate the activator for participant.
      *
-     * @param parameters the parameters for the participant intermediary
-     * @throws ControlLoopRuntimeException when the activation fails
+     * @param applicationContext ApplicationContext
+     * @param parameters the ParticipantParameters
      */
-    public IntermediaryActivator(final ParticipantIntermediaryParameters parameters) {
-        this.parameters = parameters;
-
-        topicSinks =
-            TopicEndpointManager.getManager().addTopicSinks(parameters.getClampControlLoopTopics().getTopicSinks());
+    public IntermediaryActivator(final ApplicationContext applicationContext, final ParticipantParameters parameters) {
+        this.applicationContext = applicationContext;
 
-        topicSources =
-            TopicEndpointManager.getManager().addTopicSources(parameters.getClampControlLoopTopics().getTopicSources());
-
-        try {
-            this.msgDispatcher = new MessageTypeDispatcher(MSG_TYPE_NAMES);
-        } catch (final RuntimeException e) {
-            throw new ControlLoopRuntimeException(Status.INTERNAL_SERVER_ERROR,
-                "topic message dispatcher failed to start", e);
-        }
+        topicSources = TopicEndpointManager.getManager()
+                .addTopicSources(parameters.getIntermediaryParameters().getClampControlLoopTopics().getTopicSources());
 
         // @formatter:off
-        final AtomicReference<ParticipantStatusPublisher>     statusPublisher                = new AtomicReference<>();
-        final AtomicReference<ParticipantStateChangeListener> participantStateChangeListener = new AtomicReference<>();
-        final AtomicReference<ParticipantHealthCheckListener> participantHealthCheckListener = new AtomicReference<>();
-        final AtomicReference<ControlLoopStateChangeListener> controlLoopStateChangeListener = new AtomicReference<>();
-        final AtomicReference<ControlLoopUpdateListener>      controlLoopUpdateListener      = new AtomicReference<>();
 
         addAction("Topic endpoint management",
             () -> TopicEndpointManager.getManager().start(),
             () -> TopicEndpointManager.getManager().shutdown());
 
-        addAction("Participant Status Publisher",
-            () -> statusPublisher.set(new ParticipantStatusPublisher(topicSinks)),
-            () -> statusPublisher.get().close());
-
-        addAction("Participant Handler",
-            () -> participantHandler.set(new ParticipantHandler(parameters, statusPublisher.get())),
-            () -> participantHandler.get().close());
-
-        addAction("Participant State Change Listener",
-            () -> participantStateChangeListener.set(new ParticipantStateChangeListener(participantHandler.get())),
-            () -> participantStateChangeListener.get().close());
-
-        addAction("Participant Health Check Listener",
-            () -> participantHealthCheckListener.set(new ParticipantHealthCheckListener(participantHandler.get())),
-            () -> participantHealthCheckListener.get().close());
-
-        addAction("Control Loop State Change Listener",
-            () -> controlLoopStateChangeListener.set(new ControlLoopStateChangeListener(participantHandler.get())),
-            () -> controlLoopStateChangeListener.get().close());
-
-        addAction("Control Loop Update Listener",
-            () -> controlLoopUpdateListener.set(new ControlLoopUpdateListener(participantHandler.get())),
-            () -> controlLoopUpdateListener.get().close());
-
         addAction("Topic Message Dispatcher", this::registerMsgDispatcher, this::unregisterMsgDispatcher);
         // @formatter:on
     }
 
     /**
+     * Handle ContextRefreshEvent.
+     *
+     * @param ctxRefreshedEvent ContextRefreshedEvent
+     */
+    @EventListener
+    public void handleContextRefreshEvent(ContextRefreshedEvent ctxRefreshedEvent) {
+        if (!isAlive()) {
+            start();
+        }
+    }
+
+    /**
+     * Handle ContextClosedEvent.
+     *
+     * @param ctxClosedEvent ContextClosedEvent
+     */
+    @EventListener
+    public void handleContextClosedEvent(ContextClosedEvent ctxClosedEvent) {
+        if (isAlive()) {
+            stop();
+        }
+    }
+
+    /**
      * Registers the dispatcher with the topic source(s).
      */
     private void registerMsgDispatcher() {
+        MessageTypeDispatcher msgDispatcher = applicationContext.getBean(MessageTypeDispatcher.class);
+
         msgDispatcher.register(ParticipantMessageType.PARTICIPANT_STATE_CHANGE.name(),
-            (ScoListener<ParticipantStateChange>) new ParticipantStateChangeListener(participantHandler.get()));
+                applicationContext.getBean(ParticipantStateChangeListener.class));
+
         msgDispatcher.register(ParticipantMessageType.PARTICIPANT_HEALTH_CHECK.name(),
-            (ScoListener<ParticipantHealthCheck>) new ParticipantHealthCheckListener(participantHandler.get()));
+                applicationContext.getBean(ParticipantHealthCheckListener.class));
+
         msgDispatcher.register(ParticipantMessageType.PARTICIPANT_CONTROL_LOOP_STATE_CHANGE.name(),
-            (ScoListener<ParticipantControlLoopStateChange>) new ControlLoopStateChangeListener(
-                participantHandler.get()));
+                applicationContext.getBean(ControlLoopStateChangeListener.class));
+
         msgDispatcher.register(ParticipantMessageType.PARTICIPANT_CONTROL_LOOP_UPDATE.name(),
-            (ScoListener<ParticipantControlLoopUpdate>) new ControlLoopUpdateListener(participantHandler.get()));
+                applicationContext.getBean(ControlLoopUpdateListener.class));
+
         for (final TopicSource source : topicSources) {
             source.register(msgDispatcher);
         }
@@ -148,17 +123,15 @@ public class IntermediaryActivator extends ServiceManagerContainer {
      * Unregisters the dispatcher from the topic source(s).
      */
     private void unregisterMsgDispatcher() {
+        MessageTypeDispatcher msgDispatcher = applicationContext.getBean(MessageTypeDispatcher.class);
+
         for (final TopicSource source : topicSources) {
             source.unregister(msgDispatcher);
         }
     }
 
-    /**
-     * Return the participant handler.
-     *
-     * @return the participant handler
-     */
-    public ParticipantHandler getParticipantHandler() {
-        return participantHandler.get();
+    @Override
+    public void close() throws IOException {
+        super.shutdown();
     }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java
index 5e414b175..1c54658fa 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java
@@ -28,6 +28,8 @@ import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantHealthStatus;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantStatistics;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopStateChange;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantHealthCheck;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantMessage;
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseDetails;
@@ -35,15 +37,17 @@ import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.Parti
 import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStateChange;
 import org.onap.policy.clamp.controlloop.participant.intermediary.comm.MessageSender;
 import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantStatusPublisher;
-import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantParameters;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
 
 /**
  * This class is responsible for managing the state of a participant.
  */
 @Getter
+@Component
 public class ParticipantHandler implements Closeable {
     private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantHandler.class);
 
@@ -65,18 +69,18 @@ public class ParticipantHandler implements Closeable {
      * @param parameters the parameters of the participant
      * @param publisher the publisher for sending responses to messages
      */
-    public ParticipantHandler(ParticipantIntermediaryParameters parameters, ParticipantStatusPublisher publisher) {
-        this.participantType = parameters.getParticipantType();
-        this.participantId = parameters.getParticipantId();
-        this.sender = new MessageSender(this, publisher, parameters.getReportingTimeInterval());
-        this.controlLoopHandler = new ControlLoopHandler(parameters, sender);
+    public ParticipantHandler(ParticipantParameters parameters, ParticipantStatusPublisher publisher) {
+        this.participantType = parameters.getIntermediaryParameters().getParticipantType();
+        this.participantId = parameters.getIntermediaryParameters().getParticipantId();
+        this.sender =
+                new MessageSender(this, publisher, parameters.getIntermediaryParameters().getReportingTimeInterval());
+        this.controlLoopHandler = new ControlLoopHandler(parameters.getIntermediaryParameters(), sender);
         this.participantStatistics = new ParticipantStatistics();
     }
 
     @Override
     public void close() {
         sender.close();
-        controlLoopHandler.close();
     }
 
     /**
@@ -133,6 +137,24 @@ public class ParticipantHandler implements Closeable {
     }
 
     /**
+     * Handle a control loop update message.
+     *
+     * @param updateMsg the update message
+     */
+    public void handleControlLoopUpdate(ParticipantControlLoopUpdate updateMsg) {
+        controlLoopHandler.handleControlLoopUpdate(updateMsg);
+    }
+
+    /**
+     * Handle a control loop state change message.
+     *
+     * @param stateChangeMsg the state change message
+     */
+    public void handleControlLoopStateChange(ParticipantControlLoopStateChange stateChangeMsg) {
+        controlLoopHandler.handleControlLoopStateChange(stateChangeMsg);
+    }
+
+    /**
      * Method to handle when the new state from participant is active.
      *
      * @param response participant response
@@ -233,4 +255,14 @@ public class ParticipantHandler implements Closeable {
     public boolean canHandle(ParticipantMessage partipantMsg) {
         return partipantMsg.appliesTo(participantType, participantId);
     }
+
+    /**
+     * Check if a participant message applies to this participant handler.
+     *
+     * @param partipantMsg the message to check
+     * @return true if it applies, false otherwise
+     */
+    public boolean appliesTo(ParticipantMessage partipantMsg) {
+        return partipantMsg.appliesTo(participantType, participantId);
+    }
 }
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryFactory.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/parameters/ParticipantParameters.java
index d7cc4b2ed..c350b1b95 100644
--- a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryFactory.java
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/parameters/ParticipantParameters.java
@@ -18,21 +18,9 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.policy.clamp.controlloop.participant.intermediary.api;
+package org.onap.policy.clamp.controlloop.participant.intermediary.parameters;
 
-import org.onap.policy.clamp.controlloop.participant.intermediary.api.impl.ParticipantIntermediaryApiImpl;
+public interface ParticipantParameters {
 
-/**
- * Factory class for creating {@link ParticipantIntermediaryApi} instances.
- */
-public class ParticipantIntermediaryFactory {
-
-    /**
-     * Create an implementation of the {@link ParticipantIntermediaryApi} interface.
-     *
-     * @return the implementation of the API
-     */
-    public ParticipantIntermediaryApi createApiImplementation() {
-        return new ParticipantIntermediaryApiImpl();
-    }
+    ParticipantIntermediaryParameters getIntermediaryParameters();
 }