[ERROR] javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract com.example.gwt.loginsample.businessobjects.UserAccount[] com.example.gwt.loginsample.client.UserAccountService.retrieveAllUserAccounts() throws com.example.gwt.loginsample.shared.WrapperException' threw an unexpected exception: java.lang.NoClassDefFoundError: java.io.FileOutputStream is a restricted class. Please see the Google  App Engine developer's guide for more details.
	at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
	at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)
	at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
	at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
	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$CachedChain.doFilter(ServletHandler.java:1166)
	at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
	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$CachedChain.doFilter(ServletHandler.java:1157)
	at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:94)
	at org.mortbay.jetty.servlet.ServletHandler$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.NoClassDefFoundError: java.io.FileOutputStream is a restricted class. Please see the Google  App Engine developer's guide for more details.
	at com.google.appengine.tools.development.agent.runtime.Runtime.reject(Runtime.java:51)
	at org.apache.derby.impl.services.stream.SingleStream.PBmakeFileHPW(Unknown Source)
	at org.apache.derby.impl.services.stream.SingleStream.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at org.apache.derby.impl.services.stream.SingleStream.makeFileHPW(Unknown Source)
	at org.apache.derby.impl.services.stream.SingleStream.createDefaultStream(Unknown Source)
	at org.apache.derby.impl.services.stream.SingleStream.makeStream(Unknown Source)
	at org.apache.derby.impl.services.stream.SingleStream.boot(Unknown Source)
	at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
	at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
	at org.apache.derby.impl.services.monitor.BaseMonitor.startModule(Unknown Source)
	at org.apache.derby.iapi.services.monitor.Monitor.startSystemModule(Unknown Source)
	at org.apache.derby.impl.services.monitor.BaseMonitor.runWithState(Unknown Source)
	at org.apache.derby.impl.services.monitor.FileMonitor.<init>(Unknown Source)
	at org.apache.derby.iapi.services.monitor.Monitor.startMonitor(Unknown Source)
	at org.apache.derby.iapi.jdbc.JDBCBoot.boot(Unknown Source)
	at org.apache.derby.jdbc.EmbeddedDriver.boot(Unknown Source)
	at org.apache.derby.jdbc.EmbeddedDriver.<clinit>(Unknown Source)
	at org.apache.derby.jdbc.AutoloadedDriver.getDriverModule(Unknown Source)
	at org.apache.derby.jdbc.AutoloadedDriver.connect(Unknown Source)
	at java.sql.DriverManager.getConnection(DriverManager.java:582)
	at java.sql.DriverManager.getConnection(DriverManager.java:207)
	at com.example.gwt.loginsample.server.UserAccountServiceImpl.retrieveAllUserAccounts(UserAccountServiceImpl.java:67)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	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.RPC.invokeAndEncodeResponse(RPC.java:569)
	... 34 more