[ONOS-2408]Data model and utility class about RFC 7047 (ovsdb protocol).
The whole lib of ovsdb provides the function of encode to jasonRPC and
decode to Pojo to consumer, the bussiness of coordination of
communication is implemented by adapter.

Change-Id: I4c35426273394c1699207e5a4f2e98cead59f1e1
diff --git a/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/error/UnknownResultException.java b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/error/UnknownResultException.java
new file mode 100644
index 0000000..ab30fb1
--- /dev/null
+++ b/ovsdb/rfc/src/main/java/org/onosproject/ovsdb/rfc/error/UnknownResultException.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2015 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.ovsdb.rfc.error;
+
+/**
+ * This exception is thrown when a result does not meet any of the known formats
+ * in RFC7047.
+ */
+public class UnknownResultException extends RuntimeException {
+    private static final long serialVersionUID = 1377011546616825375L;
+
+    /**
+     * Constructs a UnknownResultException object.
+     * @param message error message
+     */
+    public UnknownResultException(String message) {
+        super(message);
+    }
+
+    /**
+     * Constructs a UnknownResultException object.
+     * @param message error message
+     * @param cause Throwable
+     */
+    public UnknownResultException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}