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/errors/InvalidApplicationException.java b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidApplicationException.java
new file mode 100644
index 0000000..290f537
--- /dev/null
+++ b/apps/kafka-integration/src/main/java/org/onosproject/kafkaintegration/errors/InvalidApplicationException.java
@@ -0,0 +1,30 @@
+/**
+ * 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.errors;
+
+/**
+ * Represents that an unregistered application trying to subscribe to ONOS
+ * events.
+ *
+ */
+public class InvalidApplicationException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    public InvalidApplicationException(String message) {
+        super(message);
+    }
+
+}