Android 到服务器上的 Appengine RPC Nullponter

我有一个 Appengine 连接的 Andorid 项目，用于在服务器和 Android 设备之间启用 RPC 调用。当我在 GWT 客户端上进行调用时，一切都运行良好，但是当我从 Android 应用程序进行调用时，服务器会抛出此 nullpointer 异常。我正在使用 Requestfactory 进行 RPC 调用。 GAE 版 1.5.2

[ERROR] Unexpected error
java.lang.NullPointerException
    at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:768)
    at com.google.web.bindery.requestfactory.server.ServiceLayerCache.getOrCache(ServiceLayerCache.java:225)
    at com.google.web.bindery.requestfactory.server.ServiceLayerCache.resolveRequestFactory(ServiceLayerCache.java:198)
    at com.google.web.bindery.requestfactory.server.SimpleRequestProcessor.process(SimpleRequestProcessor.java:203)
    at com.google.web.bindery.requestfactory.server.SimpleRequestProcessor.process(SimpleRequestProcessor.java:127)
    at com.google.web.bindery.requestfactory.server.RequestFactoryServlet.doPost(RequestFactoryServlet.java:133)
    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$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
    at org.mortbay.jetty.servlet.ServletHandler$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: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)

问题是堆栈跟踪不提供有关代码中某些问题的任何信息。

我想要做的是从 Android 客户端向 AppEngine 服务器发送异常。这就是 android 端代码。

new AsyncTask<Void, Void, Void>() {

            @Override
            protected Void doInBackground(Void... arg0) {
                MyRequestFactory factory = (MyRequestFactory) Util
                .getRequestFactory(context,
                        MyRequestFactory.class);
                ExceptionRequest request = factory.exceptionRequest();

                ExceptionProxy ep = request.create(ExceptionProxy.class);
                ep.setClassName(aThrowable.getClass().getSimpleName());
                ep.setRevision(1);
                ep.setVersionName("2.1.2");
                ep.setStack("");

                request.updateException(ep).fire();
                return null;
            }

        }.execute();

并抛出此异常(内部服务器错误)

09-05 22:29:36.104: ERROR/AndroidRuntime(602): Caused by: java.lang.RuntimeException: Internal Server Error
09-05 22:29:36.104: ERROR/AndroidRuntime(602):     at com.google.web.bindery.requestfactory.shared.Receiver.onFailure(Receiver.java:44)
09-05 22:29:36.104: ERROR/AndroidRuntime(602):     at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext.fail(AbstractRequestContext.java:677)
09-05 22:29:36.104: ERROR/AndroidRuntime(602):     ... 13 more

在 Web 客户端上执行 RPC 工作完美，但在 Android 上我无法使其工作。