将 JPA 与 EclipseLink 实现结合使用。

代码:

try{
    if(!em.getTransaction().isActive())
        em.getTransaction().begin(); 
    System.out.println(2);
    em.persist(currentUser);
    System.out.println(3);
    if (em.getTransaction().isActive()){
        System.out.println("IS ACTIVE");
    } else {
        System.out.println("NO ACTIVE");
    }
    em.getTransaction().commit();
    System.out.println(4);
    } catch (Exception e){
    completed = false;
    em.getTransaction().rollback();
    System.out.println("ERROR: " + e.getMessage());
}

错误:

INFO: persistOne - Enter
INFO: 2
INFO: 3
INFO: IS ACTIVE
INFO: [EL Warning]: 2012-01-06 14:45:59.221--UnitOfWork(12492659)--java.lang.IllegalStateException: During synchronization a new object was found through a relationship that was not marked cascade PERSIST: com.maze.model.UserDetail@d52ea.

WARNING: #{accountController.performRegister}: java.lang.IllegalStateException: 
Exception Description: No transaction is currently active
javax.faces.FacesException: #{accountController.performRegister}: java.lang.IllegalStateException: 
Exception Description: No transaction is currently active
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:118)
    at javax.faces.component.UICommand.broadcast(UICommand.java:315)
    at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
    at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
    at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
    at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:330)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:174)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:828)
    at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:725)
    at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1019)
    at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
    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:662)
Caused by: javax.faces.el.EvaluationException: java.lang.IllegalStateException: 
Exception Description: No transaction is currently active
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
    at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
    ... 32 more
Caused by: java.lang.IllegalStateException: 
Exception Description: No transaction is currently active
    at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.rollback(EntityTransactionImpl.java:122)
    at com.maze.service.UserService.persistOne(UserService.java:63)
    at com.maze.controller.request.AccountController.performRegister(AccountController.java:62)
    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.sun.el.parser.AstValue.invoke(AstValue.java:234)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:297)
    at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
    at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
    ... 33 more

奇怪的是事务处于 Activity 状态，但接下来发生的是不活动错误。

编辑 EntityManager 单例: 公共(public)类 EntityManagerSingleton {

private EntityManagerSingleton(){
}

private static class EMSingletonHolder{
    private static final EntityManagerFactory emf = Persistence.createEntityManagerFactory("Maze");
    private static final EntityManager em = emf.createEntityManager();
}

public static EntityManager getInstance(){
    return EMSingletonHolder.em;
}

*获取em实例:*

public abstract class AbstractService {
protected EntityManager em;

public AbstractService(){
    em = EntityManagerSingleton.getInstance();
}
}

所有其他服务都扩展了 AbstractService

最佳答案

请注意，最后一个异常是由 catch block 中的 rollback() 抛出的。

因此，commit() 抛出以下异常:

java.lang.IllegalStateException: During synchronization a new object was found through a relationship that was not marked cascade PERSIST: com.maze.model.UserDetail@d52ea.

该异常会导致隐式回滚，因此 catch block 中的手动 rollback() 会因非 Activity 事务而引发另一个异常。

为了可靠的手动清理，您还需要在 catch block 中调用 rollback() 之前检查事务是否处于 Activity 状态。

关于java - JPA 当前没有交易 Activity ，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/8758166/