title: GWT Cannot Serialize My Object from Hibernate
body: <p>Here is the error I am receiving. I've looked everywhere for answers and I cannot figure out why anyone else isn't running into the same issue. The error happens when I'm retrieving a Proposal object from Hibernate which has a many-to-one constraint with User_Info on two properties, author and advisor. If needed I can provide the classes and hibernate configs. Just a note, I do implement isSerializeable and have empty constructors...I really appreciate any advice or help...</p>
  
  <pre><code>Starting Jetty on port 8888
     [WARN] Exception while dispatching incoming RPC call
  com.google.gwt.user.client.rpc.SerializationException: java.lang.reflect.InvocationTargetException
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeWithCustomSerializer(ServerSerializationStreamWriter.java:760)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:723)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:612)
   at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:129)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:152)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:534)
   at com.google.gwt.user.server.rpc.RPC.encodeResponse(RPC.java:609)
   at com.google.gwt.user.server.rpc.RPC.encodeResponseForSuccess(RPC.java:467)
   at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:564)
   at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:188)
   at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:224)
   at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
   at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
   at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
   at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
   at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
   at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:729)
   at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
   at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
   at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49)
   at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
   at org.mortbay.jetty.Server.handle(Server.java:324)
   at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
   at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843)
   at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
   at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
   at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
   at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
   at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)
  Caused by: java.lang.reflect.InvocationTargetException
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:616)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeWithCustomSerializer(ServerSerializationStreamWriter.java:742)
   ... 30 more
  **Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'edu.scranton.segpis.client.shared.User_Info_$$_javassist_2' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = edu.scranton.segpis.client.shared.User_Info@1497d11**
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:610)
   at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:129)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:152)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:534)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeClass(ServerSerializationStreamWriter.java:700)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:730)
   at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:612)
   at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:129)
   at com.google.gwt.user.client.rpc.core.java.util.Collection_CustomFieldSerializerBase.serialize(Collection_CustomFieldSerializerBase.java:43)
   at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serialize(ArrayList_CustomFieldSerializer.java:36)
   ... 35 more
  [ERROR] 500 - POST /uofsisweb/thesisproposal (127.0.0.1) 57 bytes
     Request headers
        Host: 127.0.0.1:8888
        User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.12) Gecko/20101027 Ubuntu/10.10 (maverick) Firefox/3.6.12
        Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
        Accept-Language: en-us,en;q=0.5
        Accept-Encoding: gzip,deflate
        Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
        Keep-Alive: 115
        Connection: keep-alive
        Cache-Control: no-cache
        Referer: 
  
        X-GWT-Permutation: HostedMode
       X-GWT-Module-Base: 
  
        Content-Type: text/x-gwt-rpc; charset=utf-8
        Content-Length: 185
        Pragma: no-cache
     Response headers
        Content-Type: text/plain
  </code></pre>