我正在尝试在GlassFish项目中设置JMS。
我遵循书中的指导原则：“使用GlassFish 3 Application Server的Java EE 6”。
我将连接器资源设置为“jms / GlassFishWebDevConnectionFactory”，并将队列设置为“jms / GlassFishWebDevQueue”。
以下代码是从Singleton Bean执行的：
public class MessageSender {
@Resource(mappedName = "jms/GlassFishWebDevConnectionFactory")
private ConnectionFactory connectionFactory;
@Resource(mappedName = "jms/GlassFishWebDevQueue")
private Queue queue;
public void postMessages() {
try {
Connection con = connectionFactory.createConnection();
}catch (JMSException ex) {
Logger.getLogger(MessageSender.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
应用程序的初始化在“Connection con = connectionFactory.createConnection（）;”处失败。使用NullPointerException。
这是完整的堆栈跟踪：
javax.ejb.CreateException: Initialization failed for Singleton WorldBean
at com.sun.ejb.containers.AbstractSingletonContainer.createSingletonEJB(AbstractSingletonContainer.java:547)
at com.sun.ejb.containers.AbstractSingletonContainer.access$100(AbstractSingletonContainer.java:79)
at com.sun.ejb.containers.AbstractSingletonContainer$SingletonContextFactory.create(AbstractSingletonContainer.java:719)
at com.sun.ejb.containers.AbstractSingletonContainer.instantiateSingletonInstance(AbstractSingletonContainer.java:451)
at org.glassfish.ejb.startup.SingletonLifeCycleManager.initializeSingleton(SingletonLifeCycleManager.java:216)
at org.glassfish.ejb.startup.SingletonLifeCycleManager.initializeSingleton(SingletonLifeCycleManager.java:210)
at org.glassfish.ejb.startup.SingletonLifeCycleManager.initializeSingleton(SingletonLifeCycleManager.java:177)
at org.glassfish.ejb.startup.SingletonLifeCycleManager.doStartup(SingletonLifeCycleManager.java:155)
at org.glassfish.ejb.startup.EjbApplication.start(EjbApplication.java:177)
at org.glassfish.internal.data.EngineRef.start(EngineRef.java:130)
at org.glassfish.internal.data.ModuleInfo.start(ModuleInfo.java:269)
at org.glassfish.internal.data.ApplicationInfo.start(ApplicationInfo.java:301)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:461)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:240)
at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:389)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$1.execute(CommandRunnerImpl.java:348)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:363)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1085)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1200(CommandRunnerImpl.java:95)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1291)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1259)
at com.sun.enterprise.v3.admin.AdminAdapter.doCommand(AdminAdapter.java:461)
at com.sun.enterprise.v3.admin.AdminAdapter.service(AdminAdapter.java:212)
at com.sun.grizzly.tcp.http11.GrizzlyAdapter.service(GrizzlyAdapter.java:179)
at com.sun.enterprise.v3.server.HK2Dispatcher.dispath(HK2Dispatcher.java:117)
at com.sun.enterprise.v3.services.impl.ContainerMapper$Hk2DispatcherCallable.call(ContainerMapper.java:354)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:849)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:746)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1045)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:228)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:636)
Caused by: java.lang.NullPointerException
at tier_controller.MessageSender.postMessages(MessageSender.java:31)
at tier_controller.WorldBean.init(WorldBean.java:28)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.sun.ejb.containers.interceptors.BeanCallbackInterceptor.intercept(InterceptorManager.java:1009)
at com.sun.ejb.containers.interceptors.CallbackChainImpl.invokeNext(CallbackChainImpl.java:65)
at com.sun.ejb.containers.interceptors.CallbackInvocationContext.proceed(CallbackInvocationContext.java:113)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCallback(SystemInterceptorProxy.java:138)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.init(SystemInterceptorProxy.java:120)
at sun.reflect.GeneratedMethodAccessor106.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at com.sun.ejb.containers.interceptors.CallbackInterceptor.intercept(InterceptorManager.java:964)
at com.sun.ejb.containers.interceptors.CallbackChainImpl.invokeNext(CallbackChainImpl.java:65)
at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:393)
at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:376)
at com.sun.ejb.containers.AbstractSingletonContainer.createSingletonEJB(AbstractSingletonContainer.java:538)
... 40 more<code>
我现在干了好几个小时，我检查了我发现的两次tipp。所需资源正在运行，@ Resource Syntax也应该有效。
我完全不知道如何追踪或修复此错误。
答案 0 :(得分：0)
你想调试它以找出问题所在 - 你可以在jpda选项中设置suspend标志，这样你就可以在 app开始初始化之前连接到debug 。
另外，如果需要，您可以在IDE中为NPE设置断点异常（运行 - >在Intellij Idea中查看断点 - > ..）。