EntityManager在JBoss JSF bean中的merge()上引发TransactionRequiredException [英] EntityManager throws TransactionRequiredException on merge() in JBoss JSF bean

问题描述

我已经在JBoss 5.0.1GA上设置了一个JSF应用程序，以在表中显示用户列表，并允许通过每个用户旁边的按钮删除单个用户.

I've set up a JSF application on JBoss 5.0.1GA to present a list of Users in a table and allow deleting of individual users via a button next to each user.

调用deleteUser时，该调用将传递到UserDAOBean，该用户将从JBoss注入EntityManager.

When deleteUser is called, the call is passed to a UserDAOBean which gets an EntityManager injected from JBoss.

我正在使用代码

public void delete(E entity)
{
    em.remove(em.merge(entity));
}

删除用户(JPA教程中的代码为c& p).仅仅调用em.remove(entity)无效，仍然会导致相同的异常.

to delete the user (code was c&p from a JPA tutorial). Just calling em.remove(entity) has no effect and still causes the same exception.

到达此行时，我收到了TransactionRequiredException:

When this line is reached, I'm getting a TransactionRequiredException:

(跳过似乎不相关的stacktrace-stuff)

(skipping apparently irrelevant stacktrace-stuff)

...

...

20:38:06,406错误[[Faces Servlet]] Servlet Faces的Servlet.service() Servlet抛出异常 javax.persistence.TransactionRequiredException: EntityManager必须在 交易于 org.jboss.jpa.deployment.ManagedEntityManagerFactory.verifyInTx(ManagedEntityManagerFactory.java:155) 在 org.jboss.jpa.tx.TransactionScopedEntityManager.merge(TransactionScopedEntityManager.java:192) 在 at.fhj.itm.utils.DAOImplTemplate.delete(DAOImplTemplate.java:54) 在 at.fhj.itm.UserBean.delete(UserBean.java:53) 在 sun.reflect.NativeMethodAccessorImpl.invoke0(本机 方法)

20:38:06,406 ERROR [[Faces Servlet]] Servlet.service() for servlet Faces Servlet threw exception javax.persistence.TransactionRequiredException: EntityManager must be access within a transaction at org.jboss.jpa.deployment.ManagedEntityManagerFactory.verifyInTx(ManagedEntityManagerFactory.java:155) at org.jboss.jpa.tx.TransactionScopedEntityManager.merge(TransactionScopedEntityManager.java:192) at at.fhj.itm.utils.DAOImplTemplate.delete(DAOImplTemplate.java:54) at at.fhj.itm.UserBean.delete(UserBean.java:53) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

...

我已经尝试在其周围包装一个手动管理的事务(em.getTransaction().begin()+ .commit())，但这失败了，因为JBoss容器中不允许这样做.我也没有与UserTransaction成功.在网络上搜索此问题的情况也没有类似的情况和解决方案.

I already tried to wrap a manually managed transaction (em.getTransaction().begin() + .commit() ) around it, but this failed because it is not allowed within JBoss container. I had no success with UserTransaction either. Searches on the web for this issue also turned up no similar case and solution.

任何人以前都经历过类似的事情并找到了解决方案吗?

Has anyone experienced something similar before and found a solution to this?

推荐答案

找到了丢失的链接.

这确实是丢失的事务，但是解决方案不是使用EntityManager来处理它，而是添加注入的UserTransaction.

It was indeed a missing transaction but the solution was not to use the EntityManager to handle it but to add an injected UserTransaction.

@Resource
UserTransaction ut;
...
public void delete(E entity)
{
        ut.begin();
        em.remove(em.merge(entity));
        ut.commit();
}

感谢所有建议，这些建议以某种方式导致了100个弯道.

Thanks to all suggestions which somehow over 100 corners lead to this solution.

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