Adding EVPN App code

Change-Id: Id3b2192f56f054cadcd8384092245b8757a781a9
diff --git a/apps/evpnopenflow/src/main/java/org/onosproject/evpnopenflow/rsc/BasePortId.java b/apps/evpnopenflow/src/main/java/org/onosproject/evpnopenflow/rsc/BasePortId.java
new file mode 100755
index 0000000..4eb120a
--- /dev/null
+++ b/apps/evpnopenflow/src/main/java/org/onosproject/evpnopenflow/rsc/BasePortId.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2017-present Open Networking 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.
+ */
+
+package org.onosproject.evpnopenflow.rsc;
+
+import org.onlab.util.Identifier;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Immutable representation of a base port identifier.
+ */
+public final class BasePortId extends Identifier<String> {
+    // Public construction is prohibited
+    private BasePortId(String basePortId) {
+        super(checkNotNull(basePortId, "BasePortId cannot be null"));
+    }
+
+    public String portId() {
+        return identifier;
+    }
+
+    /**
+     * Creates a virtualPort id using the supplied portId.
+     *
+     * @param portId baseport identifier
+     * @return BasePortId
+     */
+    public static BasePortId portId(String portId) {
+        return new BasePortId(portId);
+    }
+}