Tracing GWT exceptions

816 views

Skip to first unread message

saurabh saurabh

unread,

Jun 20, 2011, 4:42:56 AM6/20/11

to Google Web Toolkit

For understanding the RequestFactory module of GWT I have coded my
version of 'DynaTableRf' example. While running the application in
hosted mode I get the exceptions given below, my problem is that these
exception comes nowhere from my code. So I just can't pinpoint the
problem or error.
On browser UI is as expected but data that needs to be populated
in widget is not there.

Initializing AppEngine server
[WARN] ********************************************************
There is a new version of the SDK available.
-----------
Latest SDK:
Release: 1.5.1
Timestamp: Wed Jun 01 00:19:15 PDT 2011
API versions: [1.0]

-----------
Your SDK:
Release: 1.5.0
Timestamp: Fri May 13 09:43:27 PDT 2011
API versions: [1.0]

-----------
Please visit http://code.google.com/appengine for the latest SDK.
********************************************************

Logging to JettyLogger(null) via
com.google.apphosting.utils.jetty.JettyLogger
Successfully processed D:\saurabh_gwt\DynaTable2\war\WEB-INF/appengine-
web.xml
Successfully processed D:\saurabh_gwt\DynaTable2\war\WEB-INF/web.xml
The server is running at http://localhost:8888/
school calender request called
hello kdkdddkdkkkddkdkdkdk
Mon Jun 20 01:32:25 PDT 2011 com.google.dynatable2.client.DynaTable2
SEVERE: One or more exceptions caught, see full set in
UmbrellaException#getCauses
com.google.web.bindery.event.shared.UmbrellaException: One or more
exceptions caught, see full set in UmbrellaException#getCauses
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext
$StandardPayloadDialect.processPayload(AbstractRequestContext.java:
299)
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext
$4.onTransportSuccess(AbstractRequestContext.java:951)
at
com.google.web.bindery.requestfactory.gwt.client.DefaultRequestTransport
$1.onResponseReceived(DefaultRequestTransport.java:136)
at
com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:
287)
at com.google.gwt.http.client.RequestBuilder
$1.onReadyStateChange(RequestBuilder.java:395)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:
103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:
71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
167)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:
326)
at
com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:
207)
at
com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:
132)
at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:
561)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:
269)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:
91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
at sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:
103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:
71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
167)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:
281)
at
com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:
531)
at
com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:
352)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.RuntimeException: Server Error: null
at
com.google.web.bindery.requestfactory.shared.Receiver.onFailure(Receiver.java:
36)
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequest.onFail(AbstractRequest.java:
113)
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext
$StandardPayloadDialect.processPayload(AbstractRequestContext.java:
271)
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext
$4.onTransportSuccess(AbstractRequestContext.java:951)
at
com.google.web.bindery.requestfactory.gwt.client.DefaultRequestTransport
$1.onResponseReceived(DefaultRequestTransport.java:136)
at
com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:
287)
at com.google.gwt.http.client.RequestBuilder
$1.onReadyStateChange(RequestBuilder.java:395)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:
103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:
71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
167)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:
326)
at
com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:
207)
at
com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:
132)
at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:
561)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:
269)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:
91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
at sun.reflect.GeneratedMethodAccessor19.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:
103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:
71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
167)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:
281)
at
com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:
531)
at
com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:
352)
at java.lang.Thread.run(Unknown Source)
[ERROR] One or more exceptions caught, see full set in
UmbrellaException#getCauses
java.lang.Throwable: One or more exceptions caught, see full set in
UmbrellaException#getCauses
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext
$StandardPayloadDialect.processPayload(AbstractRequestContext.java:
299)
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext
$4.onTransportSuccess(AbstractRequestContext.java:951)
at
com.google.web.bindery.requestfactory.gwt.client.DefaultRequestTransport
$1.onResponseReceived(DefaultRequestTransport.java:136)
at
com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:
287)
at com.google.gwt.http.client.RequestBuilder
$1.onReadyStateChange(RequestBuilder.java:395)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke()
at sun.reflect.DelegatingMethodAccessorImpl.invoke()
at java.lang.reflect.Method.invoke()
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:
103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:
71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
167)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:
326)
at
com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:
207)
at
com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:
132)
at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:
561)
at
com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:
269)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:
91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
at sun.reflect.GeneratedMethodAccessor19.invoke()
at sun.reflect.DelegatingMethodAccessorImpl.invoke()
at java.lang.reflect.Method.invoke()
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:
103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:
71)
at
com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:
167)
at
com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:
281)
at
com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:
531)
at
com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:
352)
at java.lang.Thread.run()
Caused by: java.lang.Throwable: Server Error: null
at
com.google.web.bindery.requestfactory.shared.Receiver.onFailure(Receiver.java:
36)
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequest.onFail(AbstractRequest.java:
113)
at
com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext
$StandardPayloadDialect.processPayload(AbstractRequestContext.java:
271)
... 29 more

Thanks in advance.

Thomas Broyer

unread,

Jun 20, 2011, 8:30:57 AM6/20/11

to google-we...@googlegroups.com

On Monday, June 20, 2011 10:42:56 AM UTC+2, saurabh saurabh wrote:

Caused by: java.lang.RuntimeException: Server Error: null

Your code is throwing a NullPointerException on the server-side.

To trace it further, I'd suggest setting a breakpoint in com.google.web.bindery.requestfactory.server.DefaultExceptionHandler, where you'll have the full stack-trace for the exception. You can also subclass RequestFactoryServlet to pass an ExceptionHandler of your own (that will log using java.util.logging, log4j, slf4j, or whatever you're using to log on the server-side)

But it really is best to unit-test your locators and services code to find those bugs early!

mihu

unread,

Jun 28, 2011, 11:00:05 AM6/28/11

to google-we...@googlegroups.com

Hi,

In my situation, with this error:

Caused by: java.lang.RuntimeException: Server Error: null

The problem was that, I didn't set Application ID in App Engine properties, because I haven't deployed to server yet.

But of course there probably can be many reasons of NullPointerException on the server-side...

Kind regards

mihu

unread,

Sep 2, 2011, 10:26:31 AM9/2/11

to google-we...@googlegroups.com

I have tried to write this "subclass RequestFactoryServlet to pass an ExceptionHandler of your own":

package com.mydomain.myproject.server.servlet;

import com.google.web.bindery.requestfactory.server.RequestFactoryServlet;

@SuppressWarnings("serial")

public class RequestFactoryServletMihu extends RequestFactoryServlet

{

RequestFactoryServletMihu()

{

super(new DefaultExceptionHandlerMihu());

}

and:

package com.mydomain.myproject.server.servlet;

import java.util.logging.Logger;

import com.google.web.bindery.requestfactory.server.DefaultExceptionHandler;

import com.google.web.bindery.requestfactory.shared.ServerFailure;

public class DefaultExceptionHandlerMihu extends DefaultExceptionHandler

{

private static final Logger logger = Logger.getLogger(DefaultExceptionHandlerMihu.class.getCanonicalName());

@Override

public ServerFailure createServerFailure(Throwable throwable)

{

logger.finest("DefaultExceptionHandlerMihu: " + throwable.getMessage());

return super.createServerFailure(throwable);

}

and in web.xml I have:

<filter-name>gaeAuthFilter</filter-name>

<filter-class>com.mydomain.myproject.server.servlet.GaeAuthFilter</filter-class>

</filter>

<filter-mapping>

<filter-name>gaeAuthFilter</filter-name>

<servlet-name>requestFactoryServlet</servlet-name>

</filter-mapping>

<servlet-name>requestFactoryServlet</servlet-name>

<servlet-class>com.mydomain.myproject.server.servlet.RequestFactoryServletMihu</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>requestFactoryServlet</servlet-name>

<url-pattern>/gwtRequest</url-pattern>

</servlet-mapping>

and I get an error:

Logging to JettyLogger(null) via com.google.apphosting.utils.jetty.JettyLogger

Successfully processed C:\Projects\workspace\Myproject\war\WEB-INF/appengine-web.xml

Successfully processed C:\Projects\workspace\Myproject\war\WEB-INF/web.xml

The server is running at http://localhost:8888/

Fri Sep 02 16:09:53 CEST 2011 WireActivityLogger

FINEST: Sending fire request

[ERROR] javax.servlet.ServletContext log: unavailable

java.lang.IllegalAccessException: Class org.mortbay.jetty.servlet.Holder can not access a member of class com.mydomain.myproject.server.servlet.RequestFactoryServletMihu with modifiers ""

at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:65)

at java.lang.Class.newInstance0(Class.java:349)

at java.lang.Class.newInstance(Class.java:308)

at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)

at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428)

at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)

at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)

at com.mydomain.myproject.server.servlet.GaeAuthFilter.doFilter(GaeAuthFilter.java:71)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)

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:97)

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:218)

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)

[WARN] /gwtRequest