Add '0x' prefix to the hex value in toString().
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/EthType.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/EthType.java
index c5f4f86..1d9c8d6 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/EthType.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/EthType.java
@@ -218,7 +218,7 @@
 
     @Override
     public String toString() {
-        return Integer.toHexString(rawValue);
+        return "0x" + Integer.toHexString(rawValue);
     }
 
     public void write2Bytes(ChannelBuffer c) {