调用 context.lookup(“myJndiBeanName”) 返回 bean 实例？

Question

关于 EJB 3 无状态 bean jndi 从上下文查找的快速问题。 context.lookup("myBean") 是否返回 bean 的实例？我的 bean 不是单例。

我问这个问题的原因是因为我在 JBoss AS 6 上的插入和删除持久性 CRUD 服务不断出现事务超时。我有一个 Callable，其中注入了一个持久性 CRUD 无状态 bean，以便它在自己的事务中仅执行 5,000 次插入（因此存在关于返回新实例而不是每次调用返回相同实例的问题）。在 Callable.call() 方法中，我使用 context.lookup("myBean") 注入无状态 bean，因为我有大约 20 个 Callable 传递给 ExecutorService .submit(Callable)。

底线是我不明白为什么它在进程结束时超时（所有数据已成功插入：600,000 次插入），但在作业结束时，JBoss 抛出超时错误。

堆栈跟踪，“由”错误引起：

Caused by: javax.transaction.RollbackException: ARJUNA-16063 The transaction is not active!
        at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1148) [:6.0.0.Final]
        at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:119) [:6.0.0.Final]
        at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:75) [:6.0.0.Final]
        at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.endTransaction(CMTTxInterceptor.java:82) [:0.0.1]
        ... 70 more

完整堆栈跟踪：

    14:40:14,609 SEVERE [context] javax.ejb.EJBTransactionRolledbackException: Transaction rolled back: javax.faces.event.AbortProcessingException: javax.ejb.EJBTransactionRolledbackException: Transactio
 rolled back
        at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:178) [:2.0.3-]
        at javax.faces.event.ActionEvent.processListener(ActionEvent.java:84) [:2.0.3-]
        at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:773) [:2.0.3-]
        at javax.faces.component.UICommand.broadcast(UICommand.java:296) [:2.0.3-]
        at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781) [:2.0.3-]
        at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246) [:2.0.3-]
        at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77) [:2.0.3-]
        at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97) [:2.0.3-]
        at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114) [:2.0.3-]
        at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308) [:2.0.3-]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:324) [:6.0.0.Final]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:242) [:6.0.0.Final]
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [:6.0.0.Final]
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) [:6.0.0.Final]
        at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:181) [:6.0.0.Final]
        at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.event(CatalinaContext.java:285) [:1.1.0.Final]
        at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.invoke(CatalinaContext.java:261) [:1.1.0.Final]
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:88) [:6.0.0.Final]
        at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:100) [:6.0.0.Final]
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) [:6.0.0.Final]
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [:6.0.0.Final]
        at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158) [:6.0.0.Final]
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [:6.0.0.Final]
        at org.jboss.web.tomcat.service.request.ActiveRequestResponseCacheValve.invoke(ActiveRequestResponseCacheValve.java:53) [:6.0.0.Final]
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:362) [:6.0.0.Final]
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [:6.0.0.Final]
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:654) [:6.0.0.Final]
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:951) [:6.0.0.Final]
        at java.lang.Thread.run(Thread.java:619) [:1.6.0_20]
Caused by: javax.ejb.EJBTransactionRolledbackException: Transaction rolled back
        at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.handleEndTransactionException(CMTTxInterceptor.java:115) [:0.0.1]
        at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.endTransaction(CMTTxInterceptor.java:87) [:0.0.1]
        at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:255) [:0.0.1]
        at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.required(CMTTxInterceptor.java:349) [:0.0.1]
        at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.invoke(CMTTxInterceptor.java:209) [:0.0.1]
        at org.jboss.ejb3.tx2.aop.CMTTxInterceptorWrapper.invoke(CMTTxInterceptorWrapper.java:52) [:0.0.1]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76) [:1.0.0.GA]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.tx.NullInterceptor.invoke(NullInterceptor.java:42) [:1.0.3]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.security.Ejb3AuthenticationInterceptorv2.invoke(Ejb3AuthenticationInterceptorv2.java:182) [:1.7.17]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:41) [:1.7.17]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.BlockContainerShutdownInterceptor.invoke(BlockContainerShutdownInterceptor.java:67) [:1.7.17]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.core.context.CurrentInvocationContextInterceptor.invoke(CurrentInvocationContextInterceptor.java:47) [:1.7.17]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.aspects.currentinvocation.CurrentInvocationInterceptor.invoke(CurrentInvocationInterceptor.java:67) [:1.0.1]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.interceptor.EJB3TCCLInterceptor.invoke(EJB3TCCLInterceptor.java:86) [:1.7.17]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.session.SessionSpecContainer.invoke(SessionSpecContainer.java:323) [:1.7.17]
        at org.jboss.ejb3.session.SessionSpecContainer.invoke(SessionSpecContainer.java:380) [:1.7.17]
        at sun.reflect.GeneratedMethodAccessor335.invoke(Unknown Source) [:1.6.0_20]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [:1.6.0_20]
        at java.lang.reflect.Method.invoke(Method.java:597) [:1.6.0_20]
        at org.jboss.ejb3.proxy.impl.handler.session.SessionLocalProxyInvocationHandler$LocalContainerInvocation.invokeTarget(SessionLocalProxyInvocationHandler.java:184) [:1.0.11]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:111) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.async.impl.interceptor.AsynchronousClientInterceptor.invoke(AsynchronousClientInterceptor.java:143) [:1.7.17]
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102) [jboss-aop.jar:2.2.1.GA]
        at org.jboss.ejb3.proxy.impl.handler.session.SessionLocalProxyInvocationHandler$LocalInvokableContextHandler.invoke(SessionLocalProxyInvocationHandler.java:159) [:1.0.11]
        at $Proxy217.invoke(Unknown Source)     at org.jboss.ejb3.proxy.impl.handler.session.SessionProxyInvocationHandlerBase.invoke(SessionProxyInvocationHandlerBase.java:185) [:1.0.11]
        at $Proxy220.runEngine(Unknown Source)  at com.ls.forecast.web.beans.ExpectedReturnEngineBean.runEngine(ExpectedReturnEngineBean.java:20) [:]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [:1.6.0_20]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [:1.6.0_20]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [:1.6.0_20]
        at java.lang.reflect.Method.invoke(Method.java:597) [:1.6.0_20]
        at org.apache.el.parser.AstValue.invoke(AstValue.java:196) [:6.0.0.Final]
        at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276) [:6.0.0.Final]
        at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:149) [:2.0.3-]
        ... 28 more
Caused by: javax.transaction.RollbackException: ARJUNA-16063 The transaction is not active!
        at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1148) [:6.0.0.Final]
        at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:119) [:6.0.0.Final]
        at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:75) [:6.0.0.Final]
        at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.endTransaction(CMTTxInterceptor.java:82) [:0.0.1]
        ... 70 more

Answer 1

对于无状态会话 Bean，不能保证您始终获得相同的实例。这些 Bean 最常被池化，容器将仅使用池中的任何 Bean。

分布在 5k 批次中的 600k 插入在并行运行时会创建 120 个 slsb，所有这些都尝试并行访问数据库，所有尝试获取锁定等。我猜您“简单地”遇到了并行任务阻塞每个的情况其他的足以使整组事务超时并回滚。

您可以发布您的代码，因为到目前为止，这最终会读取水晶球。

Answer 2

我意识到我的设计不符合 EJB 规范，除非使用 EJB API，否则不应使用多线程。我重写了我的类，以便多线程代码位于 EJB 中并使用注释 @Asynchronous。不再需要与线程相关的代码（ExecutorService、Callable 等）。