SerializationPolicy error when performing RPC from within GWT application

Question

I\'m getting the following exception:

com.google.gwt.user.client.rpc.SerializationException: Type \'java.lang.Long\' was not included in the set of ty

Answer 1

Try deleting the *.gwt.rpc files in your war/app directory, clean and rebuild.

One thing to note: you should avoid long or Long if possible because they are
emulated on GWT (because there is no native Javascript long) and very
slow. Use int instead where ever you can.