title: Google App Engine GWT Date serialization
body: <p>I got following  error when serialize (java.util)Date field available in Object. My GWT version is 2.1.1 and APP engine SDk is 1.4.2.</p>
  
  <p>Is Any one got any idea about this issue?</p>
  
  <pre><code>com.google.gwt.user.client.rpc.SerializationException: java.lang.reflect.InvocationTargetException
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeWithCustomSerializer(ServerSerializationStreamWriter.java:764)
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:727)
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:616)
      at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter$ValueWriter$8.write(ServerSerializationStreamWriter.java:152)
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeValue(ServerSerializationStreamWriter.java:534)
      at com.google.gwt.user.server.rpc.RPC.encodeResponse(RPC.java:609)
      at com.google.gwt.user.server.rpc.RPC.encodeResponseForSuccess(RPC.java:467)
      at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:564)
      at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:207)
      at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:243)
      at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
      at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
      at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
      at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:58)
      at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
      at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
      at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
      at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
      at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
      at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
      at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
      at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
      at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
      at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
      at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:70)
      at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
      at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:351)
      at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
      at org.mortbay.jetty.Server.handle(Server.java:326)
      at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
      at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
      at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
      at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
      at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
      at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
      at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
  Caused by: java.lang.reflect.InvocationTargetException
      at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
      at java.lang.reflect.Method.invoke(Method.java:597)
      at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:100)
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeWithCustomSerializer(ServerSerializationStreamWriter.java:746)
      ... 38 more
  Caused by: com.google.gwt.user.client.rpc.SerializationException: Type 'org.datanucleus.sco.simple.Date' 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 = Fri Mar 25 06:30:00 UTC 2011
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:614)
      at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
      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:704)
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serializeImpl(ServerSerializationStreamWriter.java:734)
      at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamWriter.serialize(ServerSerializationStreamWriter.java:616)
      at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamWriter.writeObject(AbstractSerializationStreamWriter.java:126)
      at com.google.gwt.user.client.rpc.core.java.util.Collection_CustomFieldSerializerBase.serialize(Collection_CustomFieldSerializerBase.java:45)
      at com.google.gwt.user.client.rpc.core.java.util.ArrayList_CustomFieldSerializer.serialize(ArrayList_CustomFieldSerializer.java:38)
      ... 43 more
  </code></pre>
  
  <p>Thank You.</p>