[ONOS-3116] Port pair id for SFC

Change-Id: Ie9e9e29335a7aedd47ed341f55b3b77df3b2de37

+/*
+ * 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.vtnrsc;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.UUID;
+
+import com.google.common.base.Objects;
+
+/**
+ * Representation of a Port Pair ID.
+ */
+public final class PortPairId {
+
+    private final UUID portPairId;
+
+    /**
+     * Private constructor for port pair id.
+     *
+     * @param id UUID id of port pair
+     */
+    private PortPairId(UUID id) {
+        checkNotNull(id, "Port chain id can not be null");
+        this.portPairId = id;
+    }
+
+    /**
+     * Constructor to create port pair id from UUID.
+     *
+     * @param id UUID of port pair id
+     * @return object of port pair id
+     */
+    public static PortPairId portPairId(UUID id) {
+        return new PortPairId(id);
+    }
+
+    /**
+     * Constructor to create port pair id from string.
+     *
+     * @param id port pair id in string
+     * @return object of port pair id
+     */
+    public static PortPairId portPairId(String id) {
+        return new PortPairId(UUID.fromString(id));
+    }
+
+    /**
+     * Returns teh value of port pair id.
+     *
+     * @return port pair id
+     */
+    public UUID value() {
+        return portPairId;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj.getClass()  == this.getClass()) {
+            PortPairId that = (PortPairId) obj;
+            return Objects.equal(this.portPairId, that.portPairId);
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(this.portPairId);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("portPairId", portPairId.toString())
+                .toString();
+    }
+}