CLDC doesn't support deserialization with ObjectIntputStream because of its lack of reflection, so you have to build your own mechanism. If you can change the way the servlet handles the data, you could use DataInputStream/DataOutputStream to send the contents of your Vector as primitive Java data types instead of sending the object itself. BTW: for DoJa you are using CLDC 1.0 BR, ClausReceived on Tue Nov 30 07:57:42 2004