Question

将JPA与EclipseLink实现一起使用。

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，交易是活跃的，但接下来发生的事情是不活动的错误。

修改 EntityManager Singleton： 公共类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

Answer 1

请注意，rollback()在catch块中抛出了最后一个异常。

因此，commit()会引发以下异常：

java.lang.IllegalStateException：在同步过程中，通过未标记为级联的关系找到了一个新对象PERSIST：com.maze.model.UserDetail@d52ea。

该异常导致隐式回滚，因此catch块中的手动rollback()会因非活动事务而引发另一个异常。

对于可靠的手动清理，您还需要在调用catch块中的rollback()之前检查事务是否处于活动状态。

Answer 2

根据您的日志判断，您正在使用GlassFish。我假设你也在使用JTA。也许您还可以提供获取EntityManager实例的代码？此外，使用System.out语句调试是过去的事情，使用调试器，否则您的代码很难阅读。另外，你的缩进是错误的。

首先，如果您使用的是JTA，请查看以下问题：

EJBException when calling entityManager.getTransaction()

从接受的答案中引用：

获取对Java EE托管上下文中与EntityManager关联的EntityTransaction实例的引用是非法的。从   EntityManager.getTransaction（）的Java EE API文档：

返回资源级EntityTransaction对象。该   可以串行使用EntityTransaction实例来开始和提交   多笔交易。

Returns:
    EntityTransaction instance  Throws:
    IllegalStateException - if invoked on a JTA entity manager

这就是为什么如果您期望任何帮助，提供有关获取实体管理器的代码/注入的信息非常重要。

此外，为了代码可读性，您不应该多次调用em.getTransaction（）; 您应该将第一次调用分配给Transaction对象并重用它，如下所示：

//GOOD cause readable
EntityTransaction tx = em.getTransaction();
tx.begin();
em.persist(someObject);
tx.commit();

而不是

 //BAD cause hard to read
 em.getTransaction().begin();
 em.persist(someObject);
 em.getTransaction().commit(); //NO!

Answer 3

嗯，你的日志解释说，在提交过程中，Eclipselink得到了一个异常并回滚你的事务。这就是为什么你的翻译不再活跃了..

信息：[EL警告]：2012-01-06 14：45：59.221 - 的UnitOfWork（12492659） - java.lang.IllegalStateException：在同步期间，通过关系找到了新对象没有标记为级联PERSIST：com.maze.model.UserDetail@d52ea。

Answer 4

如果查看最后一个堆栈跟踪，我会看到

    at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.rollback(EntityTransactionImpl.java:122)

回滚过程中出错，而不是在提交过程中出错。我想知道这是否与关于非主体对象的警告有关;在提交结束时出现问题，以至于您的框架尝试在这样做的时候进行回滚。我敢打赌，如果你正确地注册了UserDetail个对象，问题就会清除。

JPA当前没有交易活动

4 个答案: