1. Removed type serializers, added (write|read)[0-9]*Byte[s]?(ChannelBuffer) method to value types instead.
2. Updated Masked fields for IPv4, IPv6 with specific string methods.
3. Added value types for other fields from the spec
4. Updated unit tests accordingly
5. Changed java_type.py to support multiple read/write operations per type, per OF version.
diff --git a/java_gen/pre-written/src/main/java/org/openflow/types/IpEcn.java b/java_gen/pre-written/src/main/java/org/openflow/types/IpEcn.java
new file mode 100644
index 0000000..b261d41
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/openflow/types/IpEcn.java
@@ -0,0 +1,53 @@
+package org.openflow.types;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.openflow.exceptions.OFParseError;
+
+public enum IpEcn implements OFValueType {
+    ECN_00((byte)0),
+    ECN_01((byte)1),
+    ECN_10((byte)2),
+    ECN_11((byte)3);
+    
+    static final int LENGTH = 1;
+    
+    private final byte ecn;
+    
+    private IpEcn(byte ecn) {
+        this.ecn = ecn;
+    }
+    
+    public static IpEcn of(byte ecn) {
+        switch (ecn) {
+            case 0:
+                return ECN_00;
+            case 1:
+                return ECN_01;
+            case 2:
+                return ECN_10;
+            case 3:
+                return ECN_11;
+            default:
+                throw new IllegalArgumentException("Illegal IP ECN value: " + ecn);
+        }
+    }
+
+    @Override
+    public int getLength() {
+        return LENGTH;
+    }
+
+    @Override
+    public String toString() {
+        return (ecn < 3 ? "0" : "") + Integer.toBinaryString(ecn);
+    }
+
+    public void writeByte(ChannelBuffer c) {
+        c.writeByte(this.ecn);
+    }
+
+    public static IpEcn readByte(ChannelBuffer c) throws OFParseError {
+        return IpEcn.of((byte)(c.readUnsignedByte()));
+    }
+
+}