perperyu

2009/6/22： gwt项目运行时遇到的两个异常

GWT---Google Web Toolkit

2009/6/22

今天使用gwt做bbs的分类版面遇到了许多问题，从上午到现在都在调试错误，遇到了一个又一个从来没遇到过的异常

异常一：

2009-6-22 10:48:28 com.google.apphosting.utils.jetty.JettyLogger warn

警告: Nested in java.lang.ExceptionInInitializerError:

java.security.AccessControlException: access denied (java.lang.RuntimePermission modifyThreadGroup)

at java.security.AccessControlContext.checkPermission(Unknown Source)

at java.security.AccessController.checkPermission(Unknown Source)

at java.lang.SecurityManager.checkPermission(Unknown Source)

at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkPermission(DevAppServerFactory.java:122)

at com.google.appengine.tools.development.DevAppServerFactory$CustomSecurityManager.checkAccess(DevAppServerFactory.java:149)

at java.lang.ThreadGroup.checkAccess(Unknown Source)

at java.lang.Thread.init(Unknown Source)

at java.lang.Thread.(Unknown Source)

at java.util.TimerThread.(Unknown Source)

at java.util.Timer.(Unknown Source)

at com.mysql.jdbc.Connection.(Connection.java:1087)

at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)

at java.sql.DriverManager.getConnection(Unknown Source)

at org.hibernate.connection.DriverManagerConnectionProvider.getConnection(DriverManagerConnectionProvider.java:110)

at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:84)

at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2073)

at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1298)

at com.perperyu.bbs.utils.HibernateSessionUtil.(HibernateSessionUtil.java:15)

at com.perperyu.bbs.filters.SessionTranxFilter.doFilter(SessionTranxFilter.java:39)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)

at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)

at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)

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:712)

at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)

at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:54)

at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)

at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:306)

at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)

at org.mortbay.jetty.Server.handle(Server.java:313)

at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:506)

at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:830)

at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)

at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)

at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)

at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)

at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)

这个异常。。太牛了，简直不是拿给我这种新手折腾的，想了几个小时也未果，然后按异常的关键词上google搜索，有让改java jre的配置文件的，grant几个permission.我尝试了修改，但是依然不行。于是上google的gwt论坛上寻求答案，

论坛中一共有四个帖子发布了这个问题的求助，我期盼着能从中找到答案。结果，有个人给了个解决方案，这个方案能成功解决这个异常，但这个异常究竟是什么意思，我还是搞不懂，涉及到安全控制这种底层的东西，我的java之路还很长啊。！解决办法很简单：不要使用goole的app engine就可以了。具体如下：

在eclipse3.4中，选中项目名，右键选择à属性àGoogleàApp Engineàuse Google App Engine(取消选中状态！)à确定,即可！

本来可以用这个方法迅速解决问题的，但是按网上提供的方法找不到这个选项：

选择Windowàpreferenceà GoogleàApp Engineàuse Google App Engine(取消选中状态！)………….但是我按这种方法怎么也找不到那个checkbox!用text 搜索也没找到，真晕！于是就以为那个方法不行！多次运行，尝试之后，我偶然的终于用右键的方式找到了。。。。果然可以不报这个异常了！

这个异常过后，又一个异常耗费了我大量时间：

异常二：

com.google.gwt.user.client.rpc.StatusCodeException: The call failed on the server; see server log for details

at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.onResponseReceived(RequestCallbackAdapter.java:192)

at com.google.gwt.http.client.Request.fireOnResponseReceivedImpl(Request.java:264)

at com.google.gwt.http.client.Request.fireOnResponseReceivedAndCatch(Request.java:236)

at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:227)

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.ie.IDispatchImpl.callMethod(IDispatchImpl.java:126)

at com.google.gwt.dev.shell.ie.IDispatchProxy.invoke(IDispatchProxy.java:155)

at com.google.gwt.dev.shell.ie.IDispatchImpl.Invoke(IDispatchImpl.java:294)

at com.google.gwt.dev.shell.ie.IDispatchImpl.method6(IDispatchImpl.java:194)

at org.eclipse.swt.internal.ole.win32.COMObject.callback6(COMObject.java:117)

at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)

at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:1925)

at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2966)

at com.google.gwt.dev.SwtHostedModeBase.processEvents(SwtHostedModeBase.java:235)

at com.google.gwt.dev.HostedModeBase.pumpEventLoop(HostedModeBase.java:558)

at com.google.gwt.dev.HostedModeBase.run(HostedModeBase.java:405)

at com.google.gwt.dev.HostedMode.main(HostedMode.java:232)

同因

com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException: This application is out of date, please click the refresh button on your browser.

at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.onResponseReceived(RequestCallbackAdapter.java:204)