@Transactional 在 CDI Bean 的基类中被忽略

Question

拥有以下相当简单的代码和正确配置的基于 JTA 的持久性上下文：

abstract class AbstractRepository<E> {
    @PersistenceContext
    protected EntityManager em;

    @Transactional
    public synchronized void persist(E entity) {
        em.persist(entity);
        em.flush();
    }
}

@ApplicationScoped
class MyEntityRepository extends AbstractRepository<MyEntity> {

}

我在调用MyEntityRepository.persist() 时遇到以下异常：

2015-06-23T12:34:55.233+0200|Severe: javax.persistence.TransactionRequiredException
    at com.sun.enterprise.container.common.impl.EntityManagerWrapper.doTxRequiredCheck(EntityManagerWrapper.java:161)
    at com.sun.enterprise.container.common.impl.EntityManagerWrapper.doTransactionScopedTxCheck(EntityManagerWrapper.java:151)
    at com.sun.enterprise.container.common.impl.EntityManagerWrapper.persist(EntityManagerWrapper.java:281)
    at my.project.AbstractRepository.persist(AbstractRepository.java:28)
    at my.project.QuestionnaireRepository.persist(QuestionnaireRepository.java:1)
    at my.project.QuestionnaireRepository$Proxy$_$$_WeldClientProxy.persist(Unknown Source)
    at my.project.QuestionnaireForm.save(QuestionnaireForm.java:29)
    at my.project.QuestionnaireForm.lambda$0(QuestionnaireForm.java:1)
    at my.project.QuestionnaireForm$$Lambda$56/1079229220.buttonClick(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:508)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:198)
    at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:161)
    at com.vaadin.server.AbstractClientConnector.fireEvent(AbstractClientConnector.java:977)
    at com.vaadin.ui.Button.fireClick(Button.java:393)
    at com.vaadin.ui.Button$1.click(Button.java:61)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:168)
    at com.vaadin.server.ServerRpcManager.applyInvocation(ServerRpcManager.java:118)
    at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:291)
    at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:184)
    at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:92)
    at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1408)
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:350)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.glassfish.tyrus.servlet.TyrusServletFilter.doFilter(TyrusServletFilter.java:295)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
    at java.lang.Thread.run(Thread.java:745)

为了修复它，我必须添加：

@Override
@Transactional
public void persist(Entity e) {
    super.persist(e);
}

什么可能导致这种异常？ @Transactional 注解标记为@Inherited。

Answer 1

这是因为容器在本地方法中看不到注解：在AbstractRepository 中，方法被注解但相对于MyEntityRepository 是本地的。这使得不会启动任何事务的 Glassfish 无法看到它，因此是您的例外。

QuestionnaireRepository 应该注入 MyEntityRepository 并且应该启动事务本身。

带回家的结论是：@Transactional 注释仅在业务方法上使用，它们是由“注入器”类调用的公共方法。

另见an example in which the method is in the same instance

我在考虑如何在不实现 persist 的具体类中做同样的事情，但我认为这是不可能的，因为容器必须实例化一个抽象类（这很荒谬，因为它们没有构造函数通过反射调用）。

也许您可以使用 Java 8 和接口默认方法做一些事情，这些方法作为默认行为添加到具体类中。

// UNTESTED!
public interface Repository<E> {
    @Transactional
    synchronized default void persist(E entity) {
        em.persist(entity);
    }
}

Answer 2

感谢您添加 beans.xml 文件。如果我不得不猜测，GF4 会遇到一个 CDI 1.1 错误，其中拦截器不是 bean 定义的，并且在您的应用程序中使用了错误的发现模式。如果您将 beans.xml 文件更改为使用

<beans xmlns="http://xmlns.jcp.org/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
        http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
       bean-discovery-mode="all">
</beans>

这将强制它找到所有 bean。问题是您的基类没有被发现，因此没有将事务状态应用于方法。