Kafka Codec Integration

Made changes as per the comments on patch set 2.
Made changes as per comments on patch set 3.
Made further changes and event subscription works absolutely fine now.

Change-Id: Icd20195f6c0e045d14beb73584069d486ab9290c

+/**
+ * Copyright 2016-present Open Networking Laboratory
+ * 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.
+ */
+package org.onosproject.kafkaintegration.api.dto;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Objects;
+
+import org.onosproject.kafkaintegration.api.dto.OnosEvent.Type;
+
+/**
+ * Representation of a subscription to an event type.
+ *
+ */
+public final class DefaultEventSubscriber implements EventSubscriber {
+    private final String appName;
+    private final EventSubscriberGroupId subscriberGroupId;
+    private final Type eventType;
+
+    /**
+     * Creates a new Event Subscriber.
+     *
+     * @param name Application Name
+     * @param groupId Subscriber group id of the application
+     * @param eventType ONOS event type
+     */
+    public DefaultEventSubscriber(String name, EventSubscriberGroupId groupId,
+                                  Type eventType) {
+        this.appName = checkNotNull(name);
+        this.subscriberGroupId = checkNotNull(groupId);
+        this.eventType = checkNotNull(eventType);
+    }
+
+    @Override
+    public String appName() {
+        return appName;
+    }
+
+    @Override
+    public EventSubscriberGroupId subscriberGroupId() {
+        return subscriberGroupId;
+    }
+
+    @Override
+    public Type eventType() {
+        return eventType;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(appName, subscriberGroupId, eventType);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o instanceof DefaultEventSubscriber) {
+            DefaultEventSubscriber sub = (DefaultEventSubscriber) o;
+            if (sub.appName.equals(appName)
+                    && sub.subscriberGroupId.equals(subscriberGroupId)
+                    && sub.eventType.equals(eventType)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("appName", appName)
+                .addValue(subscriberGroupId.toString())
+                .add("eventType", eventType).toString();
+    }
+    /**
+     * To create an instance of the builder.
+     *
+     * @return instance of builder
+     */
+    public static Builder builder() {
+        return new Builder();
+    }
+    /**
+     * Builder class for Event subscriber.
+     */
+    public static final class Builder implements EventSubscriber.Builder {
+        private String appName;
+        private EventSubscriberGroupId subscriberGroupId;
+        private Type eventType;
+
+        @Override
+        public Builder setAppName(String appName) {
+            this.appName = appName;
+            return this;
+        }
+
+        @Override
+        public Builder setSubscriberGroupId(EventSubscriberGroupId
+                                                            subscriberGroupId) {
+            this.subscriberGroupId = subscriberGroupId;
+            return this;
+        }
+
+        @Override
+        public Builder setEventType(Type eventType) {
+            this.eventType = eventType;
+            return this;
+        }
+
+        @Override
+        public EventSubscriber build() {
+            checkNotNull(appName, "App name cannot be null");
+            checkNotNull(subscriberGroupId, "Subscriber group ID cannot " +
+                    "be " +
+                    "null");
+            checkNotNull(eventType, "Event type cannot be null");
+
+            return new DefaultEventSubscriber(appName,
+                                              subscriberGroupId,
+                                              eventType);
+        }
+    }
+
+}

@@ -13,87 +13,42 @@
  * limitations under the License.
  */
 package org.onosproject.kafkaintegration.api.dto;
-
-import static com.google.common.base.MoreObjects.toStringHelper;
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-
 import org.onosproject.kafkaintegration.api.dto.OnosEvent.Type;
 
 /**
- * Representation of a subscription to an event type.
- *
+ * Abstraction of subscription to an event type.
  */
-public final class EventSubscriber {
-    private final String appName;
-    private final EventSubscriberGroupId subscriberGroupId;
-    private final Type eventType;
-
+public interface EventSubscriber {
     /**
-     * Creates a new Event Subscriber.
+     * Returns the application name.
      *
-     * @param name Application Name
-     * @param groupId Subscriber group id of the application
-     * @param eventType ONOS event type
+     * @return application name.
      */
-    public EventSubscriber(String name, EventSubscriberGroupId groupId,
-                           Type eventType) {
-        this.appName = checkNotNull(name);
-        this.subscriberGroupId = checkNotNull(groupId);
-        this.eventType = checkNotNull(eventType);
-    }
+    String appName();
 
     /**
-     * Returns the Application Name.
-     *
-     * @return application name
+     * Returns the subscriber group ID.
+     * @return subscriber group ID.
      */
-    public String appName() {
-        return appName;
-    }
-
-    /**
-     * Returns the Subscriber Group Id.
-     *
-     * @return Subscriber Group Id
-     */
-    public EventSubscriberGroupId subscriberGroupId() {
-        return subscriberGroupId;
-    }
+    EventSubscriberGroupId subscriberGroupId();
 
     /**
      * Returns the Event type.
      *
      * @return ONOS Event Type
      */
-    public Type eventType() {
-        return eventType;
-    }
+    Type eventType();
 
-    @Override
-    public int hashCode() {
-        return Objects.hash(appName, subscriberGroupId, eventType);
-    }
+    /**
+     * An event subscriber builder.
+     */
+    interface Builder {
+        Builder setAppName(String appName);
 
-    @Override
-    public boolean equals(Object o) {
-        if (o instanceof EventSubscriber) {
-            EventSubscriber sub = (EventSubscriber) o;
-            if (sub.appName.equals(appName)
-                    && sub.subscriberGroupId.equals(subscriberGroupId)
-                    && sub.eventType.equals(eventType)) {
-                return true;
-            }
-        }
+        Builder setSubscriberGroupId(EventSubscriberGroupId subscriberGroupId);
 
-        return false;
-    }
+        Builder setEventType(Type eventType);
 
-    @Override
-    public String toString() {
-        return toStringHelper(this).add("appName", appName)
-                .addValue(subscriberGroupId.toString())
-                .add("eventType", eventType).toString();
+        EventSubscriber build();
     }
 }

@@ -166,6 +166,7 @@
                         com.fasterxml.jackson.core,
                         org.onlab.packet.*,
                         org.onosproject.*,
+                        org.onlab.util.*,
                         com.google.common.*
                     </Import-Package>
                     <Web-ContextPath>${web.context}</Web-ContextPath>

@@ -19,6 +19,9 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static org.onosproject.kafkaintegration.api.dto.OnosEvent.Type.DEVICE;
 import static org.onosproject.kafkaintegration.api.dto.OnosEvent.Type.LINK;
 
+import org.onosproject.kafkaintegration.api.dto.DefaultEventSubscriber;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -33,8 +36,8 @@ import org.apache.felix.scr.annotations.Service;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
 import org.onosproject.kafkaintegration.api.EventExporterService;
-import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
 import org.onosproject.kafkaintegration.api.dto.EventSubscriberGroupId;
+import org.onosproject.kafkaintegration.api.dto.OnosEvent;
 import org.onosproject.kafkaintegration.api.dto.OnosEvent.Type;
 import org.onosproject.kafkaintegration.errors.InvalidApplicationException;
 import org.onosproject.kafkaintegration.errors.InvalidGroupIdException;
@@ -98,7 +101,12 @@ public class EventExporterManager implements EventExporterService {
                 .<Type, List<EventSubscriber>>consistentMapBuilder()
                 .withName(SUBSCRIBED_APPS)
                 .withSerializer(Serializer.using(KryoNamespaces.API,
-                                                 EventSubscriber.class))
+                                                 EventSubscriber.class,
+                                                 OnosEvent.class,
+                                                 OnosEvent.Type.class,
+                                                 DefaultEventSubscriber.class,
+                                                 EventSubscriberGroupId.class,
+                                                 UUID.class))
                 .build().asJavaMap();
 
         log.info("Started");
@@ -119,7 +127,6 @@ public class EventExporterManager implements EventExporterService {
         return registeredApps.computeIfAbsent(externalAppId,
                                               (key) -> new EventSubscriberGroupId(UUID
                                                       .randomUUID()));
-
     }
 
     @Override

+/**
+ * Copyright 2016-present Open Networking Laboratory
+ * 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.
+ */
+package org.onosproject.kafkaintegration.impl;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onosproject.codec.CodecService;
+import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
+import org.onosproject.kafkaintegration.rest.SubscriberCodec;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Implementation of the JSON codec brokering service for Kafka app.
+ */
+@Component(immediate = true)
+public class KafkaCodecRegistrator {
+    private static Logger log = LoggerFactory.getLogger(KafkaCodecRegistrator
+                                                                .class);
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CodecService codecService;
+
+    @Activate
+    public void activate() {
+        codecService.registerCodec(EventSubscriber.class, new SubscriberCodec());
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+}

@@ -28,7 +28,6 @@ import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 
-import org.onosproject.codec.JsonCodec;
 import org.onosproject.kafkaintegration.api.EventExporterService;
 import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
 import org.onosproject.kafkaintegration.api.dto.EventSubscriberGroupId;
@@ -54,9 +53,10 @@ public class EventExporterWebResource extends AbstractWebResource {
             "De-Registered Listener successfully";
     public static final String EVENT_SUBSCRIPTION_SUCCESSFUL =
             "Event Registration successfull";
+    public static final String EVENT_SUBSCRIPTION_UNSUCCESSFUL =
+            "Event subscription unsuccessful";
     public static final String EVENT_SUBSCRIPTION_REMOVED =
             "Event De-Registration successfull";
-
     /**
      * Registers a listener for ONOS Events.
      *
@@ -95,7 +95,7 @@ public class EventExporterWebResource extends AbstractWebResource {
         EventExporterService service = get(EventExporterService.class);
 
         service.unregisterListener(appName);
-
+        log.info("Unregistered app {}", appName);
         return ok(DEREGISTRATION_SUCCESSFUL).build();
     }
 
@@ -107,6 +107,7 @@ public class EventExporterWebResource extends AbstractWebResource {
      * @onos.rsModel KafkaSubscription
      */
     @POST
+    @Consumes(MediaType.APPLICATION_JSON)
     @Produces(MediaType.APPLICATION_JSON)
     @Path("subscribe")
     public Response subscribe(InputStream input) {
@@ -136,11 +137,10 @@ public class EventExporterWebResource extends AbstractWebResource {
 
         ObjectMapper mapper = new ObjectMapper();
         ObjectNode node = (ObjectNode) mapper.readTree(input);
-
         checkNotNull(node, JSON_NOT_NULL);
-
-        JsonCodec<EventSubscriber> codec = codec(EventSubscriber.class);
-        return codec.decode(node, this);
+        EventSubscriber codec = codec(EventSubscriber.class).decode(node, this);
+        checkNotNull(codec, JSON_NOT_NULL);
+        return codec;
     }
 
     /**

@@ -20,10 +20,10 @@ import java.util.UUID;
 
 import org.onosproject.codec.CodecContext;
 import org.onosproject.codec.JsonCodec;
+import org.onosproject.kafkaintegration.api.dto.DefaultEventSubscriber;
 import org.onosproject.kafkaintegration.api.dto.EventSubscriber;
 import org.onosproject.kafkaintegration.api.dto.EventSubscriberGroupId;
 import org.onosproject.kafkaintegration.api.dto.OnosEvent.Type;
-
 import com.fasterxml.jackson.databind.node.ObjectNode;
 
 /**
@@ -47,13 +47,18 @@ public final class SubscriberCodec extends JsonCodec<EventSubscriber> {
 
     @Override
     public EventSubscriber decode(ObjectNode json, CodecContext context) {
-        String name = json.path(NAME).asText();
-        String groupId = json.path(GROUP_ID).asText();
-        EventSubscriberGroupId subscriberGroupId = new EventSubscriberGroupId(UUID
-                .fromString(groupId));
-        String eventType = json.path(EVENT_TYPE).asText();
-
-        return new EventSubscriber(name, subscriberGroupId,
-                                   Type.valueOf(eventType));
+
+        EventSubscriber.Builder resultBuilder = new DefaultEventSubscriber
+                .Builder();
+        String appName = json.get(NAME).asText();
+        resultBuilder.setAppName(appName);
+
+        String subscriberGroupId = json.get(GROUP_ID).asText();
+        resultBuilder.setSubscriberGroupId(new EventSubscriberGroupId(UUID.
+                fromString(subscriberGroupId)));
+
+        String eventType = json.get(EVENT_TYPE).asText();
+        resultBuilder.setEventType(Type.valueOf(eventType));
+        return resultBuilder.build();
     }
-}
+}
\ No newline at end of file