Add FlowIdGenerator's implementation class.

- Updated FlowId to use long internally
- Implemented FlowIdGeneratorWithIdBlockAllocator class as an implementation class of FlowIdGenerator.

Change-Id: Id3bcb47c63217b0ea4a2f7d5ae208532783c323a
diff --git a/src/test/java/net/onrc/onos/api/flowmanager/FlowIdTest.java b/src/test/java/net/onrc/onos/api/flowmanager/FlowIdTest.java
new file mode 100644
index 0000000..49981b0
--- /dev/null
+++ b/src/test/java/net/onrc/onos/api/flowmanager/FlowIdTest.java
@@ -0,0 +1,40 @@
+package net.onrc.onos.api.flowmanager;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class FlowIdTest {
+
+    /**
+     * Tests FlowId's equals method.
+     */
+    @Test
+    public void testEquals() {
+        FlowId flow1 = new FlowId(0L);
+        FlowId flow2 = new FlowId(1L);
+        FlowId flow3 = new FlowId(2L);
+        FlowId flow4 = new FlowId(1L);
+
+        assertTrue(flow1.equals(flow1));
+        assertTrue(flow2.equals(flow2));
+        assertTrue(flow3.equals(flow3));
+        assertTrue(flow4.equals(flow4));
+
+        assertFalse(flow1.equals(flow2));
+        assertFalse(flow1.equals(flow3));
+        assertFalse(flow1.equals(flow4));
+        assertFalse(flow2.equals(flow1));
+        assertFalse(flow2.equals(flow3));
+        assertFalse(flow3.equals(flow1));
+        assertFalse(flow3.equals(flow2));
+        assertFalse(flow3.equals(flow4));
+        assertFalse(flow4.equals(flow1));
+        assertFalse(flow4.equals(flow3));
+
+        assertTrue(flow2.equals(flow4));
+        assertTrue(flow4.equals(flow2));
+    }
+
+}