如何开始调试此JDO异常？ [英] How do I start debugging this JDO exception?
本文介绍了如何开始调试此JDO异常？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
在Eclipse中以托管模式运行我的应用程序时，我会不时收到这组异常。奇怪的是，它不会一直发生。重新编译并重新启动应用程序后，会偶尔发生。重新启动Eclipse通常会清除它（没有代码更改）。有没有人有什么想法可能在这里发生什么？或者甚至我会开始寻找？
I get this set of exceptions from time to time when running my application in hosted mode in Eclipse. What's strange about it, is that it doesn't happen consistently. It will happen occasionally after recompiling and restarting the application. Restarting Eclipse will often clear it up (without a code change). does anyone have any thoughts on what might be going on here? Or even where I'd start looking?
[ERROR] javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract com.grgcomponents.coatl.client.auth.TwitterUser com.grgcomponents.coatl.client.auth.TwitterLoginService.getLoggedInUser(java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: java.lang.UnsupportedOperationException
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:378)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:581)
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$ApiProxyHandler.handle(JettyContainerService.java:349)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$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)
Caused by: java.lang.UnsupportedOperationException
at org.datanucleus.store.appengine.EntityUtils.getPropertyName(EntityUtils.java:62)
at org.datanucleus.store.appengine.DatastoreFieldManager.getPropertyName(DatastoreFieldManager.java:1073)
at org.datanucleus.store.appengine.DatastoreFieldManager.fetchObjectField(DatastoreFieldManager.java:309)
at org.datanucleus.store.appengine.DatastoreFieldManager.fetchLongField(DatastoreFieldManager.java:429)
at org.datanucleus.state.AbstractStateManager.replacingLongField(AbstractStateManager.java:1148)
at com.grgcomponents.coatl.server.persisted.TwitterOAuthTokens.jdoReplaceField(TwitterOAuthTokens.java)
at com.grgcomponents.coatl.server.persisted.TwitterOAuthTokens.jdoReplaceFields(TwitterOAuthTokens.java)
at org.datanucleus.state.JDOStateManagerImpl.replaceFields(JDOStateManagerImpl.java:2772)
at org.datanucleus.state.JDOStateManagerImpl.replaceFields(JDOStateManagerImpl.java:2791)
at org.datanucleus.store.appengine.DatastorePersistenceHandler.fetchObject(DatastorePersistenceHandler.java:480)
at org.datanucleus.state.JDOStateManagerImpl.validate(JDOStateManagerImpl.java:4263)
at org.datanucleus.ObjectManagerImpl.findObject(ObjectManagerImpl.java:2444)
at org.datanucleus.jpa.EntityManagerImpl.find(EntityManagerImpl.java:234)
at org.datanucleus.store.appengine.jpa.DatastoreEntityManager.find(DatastoreEntityManager.java:56)
at com.grgcomponents.coatl.server.auth.TwitterLoginServiceImpl.getCurrentUser(TwitterLoginServiceImpl.java:45)
at com.grgcomponents.coatl.server.auth.TwitterLoginServiceImpl.getLoggedInUser(TwitterLoginServiceImpl.java:30)
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:562)
... 30 more
[ERROR] javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String com.grgcomponents.coatl.client.preferences.UserSettingsService.getSetting(java.lang.String,java.lang.String)' threw an unexpected exception: java.lang.UnsupportedOperationException
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:378)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:581)
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:349)
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.QueuedThreacom.google.gwt.user.client.rpc.StatusCodeException: 500 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.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(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
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:157)
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:126)
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.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.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:157)
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(Thread.java:680)
dPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.UnsupportedOperationException
at org.datanucleus.store.appengine.EntityUtils.getPropertyName(EntityUtils.java:62)
at org.datanucleus.store.appengine.DatastoreFieldManager.getPropertyName(DatastoreFieldManager.java:1073)
at org.datanucleus.store.appengine.DatastoreFieldManager.fetchObjectField(DatastoreFieldManager.java:309)
at org.datanucleus.store.appengine.DatastoreFieldManager.fetchLongField(DatastoreFieldManager.java:429)
at org.datanucleus.state.AbstractStateManager.replacingLongField(AbstractStateManager.java:1148)
at com.grgcomponents.coatl.server.persisted.TwitterOAuthTokens.jdoReplaceField(TwitterOAuthTokens.java)
at com.grgcomponents.coatl.server.persisted.TwitterOAuthTokens.jdoReplaceFields(TwitterOAuthTokens.java)
at org.datanucleus.state.JDOStateManagerImpl.replaceFields(JDOStateManagerImpl.java:2772)
at org.datanucleus.state.JDOStateManagerImpl.replaceFields(JDOStateManagerImpl.java:2791)
at org.datanucleus.store.appengine.DatastorePersistenceHandler.fetchObject(DatastorePersistenceHandler.java:480)
at org.datanucleus.state.JDOStateManagerImpl.validate(JDOStateManagerImpl.java:4263)
at org.datanucleus.ObjectManagerImpl.findObject(ObjectManagerImpl.java:2444)
at org.datanucleus.jpa.EntityManagerImpl.find(EntityManagerImpl.java:234)
at org.datanucleus.store.appengine.jpa.DatastoreEntityManager.find(DatastoreEntityManager.java:56)
at com.grgcomponents.coatl.server.UserUtil.getTwitter(UserUtil.java:40)
at com.grgcomponents.coatl.server.UserUtil.getUserSetting(UserUtil.java:62)
at com.grgcomponents.coatl.server.preferences.UserSettingsServiceImpl.getSetting(UserSettingsServiceImpl.java:14)
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:562)
... 30 more
这是我试图坚持的课程：
Here's the class that I'm trying to persist:
package com.grgcomponents.coatl.server.persisted;
import javax.persistence.Entity;
import javax.persistence.Id;
@Entity
public class TwitterOAuthTokens {
@Id
private String loginManagerCookie;
private String requestTokenKey;
private String requestTokenSecret;
private String userToken;
private String userTokenSecret;
private long lastUsed;
public String getLoginManagerCookie() {
return loginManagerCookie;
}
public void setLoginManagerCookie(String loginManagerCookie) {
this.loginManagerCookie = loginManagerCookie;
}
public String getUserToken() {
return userToken;
}
public void setUserToken(String userToken) {
this.userToken = userToken;
}
public String getUserTokenSecret() {
return userTokenSecret;
}
public void setUserTokenSecret(String userTokenSecret) {
this.userTokenSecret = userTokenSecret;
}
public String getRequestTokenKey() {
return requestTokenKey;
}
public void setRequestTokenKey(String requestTokenKey) {
this.requestTokenKey = requestTokenKey;
}
public String getRequestTokenSecret() {
return requestTokenSecret;
}
public void setRequestTokenSecret(String requestTokenSecret) {
this.requestTokenSecret = requestTokenSecret;
}
public long getLastUsed() {
return lastUsed;
}
public void setLastUsed(long lastUsed) {
this.lastUsed = lastUsed;
}
}
以下是实际显示为失败（我们输入getTwitter（String），最后一行发生失败：
Here's the call that actually appears to be failing (We enter in getTwitter( String ), and the failure occurs on the last line:
public static Twitter getTwitter( String loginManagerId )
{
if( loginManagerId == null )
return null;
EntityManager em = CoatlEntityManagerFactory.getDefault()
.createEntityManager();
return getTwitter( loginManagerId, em );
}
public static Twitter getTwitter( String loginManagerId, EntityManager em )
{
if( loginManagerId == null )
return null;
TwitterOAuthTokens storedTokens = em.find( TwitterOAuthTokens.class,
loginManagerId );
推荐答案
这是一个零星的错误，不时发生在任何持久化的类上，但是moreso并行使用了很多附加在JDO和JPA中，似乎本地数据存储锁锁定一个特定的表/实体组，并忘记释放它;从而导致对ds操作的所有后续调用失败。我一般不必重新启动eclipse;只是停止然后启动服务器倾向于解决问题，如果没有，完全刷新/清理构建将做的伎俩。
This is a sporadic error that happens from time to time on any persistable class, but moreso on ones that are used a lot in parallel. It happens in JDO and JPA, and it seems as though the local datastore locks a particular table / entity group and forgets to release it; thus causing all subsequent calls to ds operations to fail. I generally don't have to restart eclipse; just stopping then starting the server tends to fix the problem, if not, a full refresh/clean build will do the trick.
唯一真正的解决方案似乎在get（）或put（）调用内部的同步代码块，这在理论上确保一次只有一个线程访问您的实体。 http://code.google.com/p/datanucleus-appengine / issues / detail？id = 203
The only real solution seems to be putting the get() or put() calls inside of a synchronized code block, which, in theory, ensures that only one thread at a time is accessing your entities. http://code.google.com/p/datanucleus-appengine/issues/detail?id=203
这篇关于如何开始调试此JDO异常？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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