[ONOS-3114] flowclassifierid

Change-Id: I731278516c4375dc036726058b8969a767be84ca
diff --git a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/FlowClassifierId.java b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/FlowClassifierId.java
index b789abe..df180eb 100644
--- a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/FlowClassifierId.java
+++ b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/FlowClassifierId.java
@@ -15,6 +15,8 @@
  */
 package org.onosproject.vtnrsc;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import com.google.common.base.MoreObjects;
 
 import java.util.UUID;
@@ -33,6 +35,7 @@
      * @param flowClassifierId flow classifier id.
      */
     private FlowClassifierId(final UUID flowClassifierId) {
+        checkNotNull(flowClassifierId, "Flow classifier id can not be null");
         this.flowClassifierId = flowClassifierId;
     }
 
@@ -42,7 +45,7 @@
      * @param flowClassifierId flow classifier id
      * @return new flow classifier id
      */
-    public static FlowClassifierId flowClassifierId(final UUID flowClassifierId) {
+    public static FlowClassifierId of(final UUID flowClassifierId) {
         return new FlowClassifierId(flowClassifierId);
     }
 
@@ -52,7 +55,7 @@
      * @param flowClassifierId flow classifier id
      * @return new flow classifier id
      */
-    public static FlowClassifierId flowClassifierId(final String flowClassifierId) {
+    public static FlowClassifierId of(final String flowClassifierId) {
         return new FlowClassifierId(UUID.fromString(flowClassifierId));
     }
 
diff --git a/apps/vtn/vtnrsc/src/test/java/org/onosproject/vtnrsc/flowclassifier/FlowClassifierIdTest.java b/apps/vtn/vtnrsc/src/test/java/org/onosproject/vtnrsc/flowclassifier/FlowClassifierIdTest.java
index b2fed34..4f52183 100644
--- a/apps/vtn/vtnrsc/src/test/java/org/onosproject/vtnrsc/flowclassifier/FlowClassifierIdTest.java
+++ b/apps/vtn/vtnrsc/src/test/java/org/onosproject/vtnrsc/flowclassifier/FlowClassifierIdTest.java
@@ -32,11 +32,11 @@
 public class FlowClassifierIdTest {
 
     final FlowClassifierId flowClassifierId1 = FlowClassifierId
-            .flowClassifierId("78dcd363-fc23-aeb6-f44b-56dc5e2fb3ae");
+            .of("78dcd363-fc23-aeb6-f44b-56dc5e2fb3ae");
     final FlowClassifierId sameAsFlowClassifierId1 = FlowClassifierId
-            .flowClassifierId("78dcd363-fc23-aeb6-f44b-56dc5e2fb3ae");
+            .of("78dcd363-fc23-aeb6-f44b-56dc5e2fb3ae");
     final FlowClassifierId flowClassifierId2 = FlowClassifierId
-            .flowClassifierId("dace4513-24fc-4fae-af4b-321c5e2eb3d1");
+            .of("dace4513-24fc-4fae-af4b-321c5e2eb3d1");
 
     /**
      * Checks that the FlowClassifierId class is immutable.
@@ -61,7 +61,7 @@
     @Test
     public void testConstruction() {
         final String flowClassifierIdValue = "dace4513-24fc-4fae-af4b-321c5e2eb3d1";
-        final FlowClassifierId flowClassifierId = FlowClassifierId.flowClassifierId(flowClassifierIdValue);
+        final FlowClassifierId flowClassifierId = FlowClassifierId.of(flowClassifierIdValue);
         assertThat(flowClassifierId, is(notNullValue()));
         assertThat(flowClassifierId.value(), is(UUID.fromString(flowClassifierIdValue)));
     }