As the DataOutputStream also writes the primitives by converting them into bytes and writing the bytes into stream, we thought of converting them ahead and writing the byteArray. we use some thing like this public byte[] convertInt(int value) { return new byte[]{ (byte) (value >>> 24), (byte) (value >>> 16), (byte) (value >>> 8), (byte) (value >>> 0), (byte) 0, (byte) 0, (byte) 0, (byte) 0}; } and this byte[] we write into the stream in writeExternal() method. public void writeExternal(final ObjectOutput out) throws IOException { out.writeInt(this.aData.length); out.write(this.aData); } This Externalizable object is a subclass of another parent object and we serialize that parent object like this. PartenObject po = new ParentObject(); ....setters ... ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream); objectOutpuStream.writeObject(po); But we see much overhead when we call this writeObject() method. So are there any optimizations in Jboss Serialization in this redard.. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4017188#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...