FlowEntry contains a FlowId

Change-Id: I8cf2cdc30865db0d5af7de5eb7e312e9ec2c0417
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/FlowId.java b/core/api/src/main/java/org/onlab/onos/net/flow/FlowId.java
new file mode 100644
index 0000000..d4e32a8
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/FlowId.java
@@ -0,0 +1,21 @@
+package org.onlab.onos.net.flow;
+
+/**
+ * Representation of a Flow ID.
+ */
+public final class FlowId {
+
+    private final int flowid;
+
+    private FlowId(int id) {
+        this.flowid = id;
+    }
+
+    public FlowId valueOf(int id) {
+        return new FlowId(id);
+    }
+
+    public int value() {
+        return flowid;
+    }
+}