CodeReview - Initial Commit for Kafka Integration Application

1. Partial REST API implementation
2. Partial Event Manager backend implementation

Change-Id: Ieaf703f7a3f6e296aea8ffcf155c7a1b603236ca
diff --git a/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriberGroupId.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriberGroupId.java
new file mode 100644
index 0000000..e0dd204
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/api/dto/EventSubscriberGroupId.java
@@ -0,0 +1,70 @@
+/**
+ * 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 java.util.UUID;
+
+/**
+ * Wrapper Object for storing the consumer group id. Group ids are used by
+ * external applications when consuming events from Kafka server.
+ *
+ */
+public final class EventSubscriberGroupId {
+    private final UUID id;
+
+    /**
+     * Creates a new Subscriber Group Id.
+     *
+     * @param uuid representing the group id.
+     */
+    public EventSubscriberGroupId(UUID uuid) {
+        id = checkNotNull(uuid);
+    }
+
+    /**
+     * Returns the Group Id of the subscriber.
+     *
+     * @return uuid representing the group id.
+     */
+    public UUID getId() {
+        return id;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o instanceof EventSubscriberGroupId) {
+            EventSubscriberGroupId sub = (EventSubscriberGroupId) o;
+            if (sub.id.equals(id)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("subscriberGroupId", id).toString();
+    }
+}