在tomcat中使用生产者注入EntityManager

Question

我在tomcat 7上使用Hibernate和Weld CDI运行一个项目.我已经编写了一个ServletContextListener来在应用程序启动期间创建EntityManagerFactory和EntityManager.

public class PersistenceListener implements ServletContextListener {

     private static EntityManagerFactory entityManagerFactory;

     public void contextInitialized(ServletContextEvent sce){
     ServletContext context = sce.getServletContext();
     entityManagerFactory = Persistence.createEntityManagerFactory("hibernate-test");
     }

     public void contextDestroyed(ServletContextEvent sce) {
     entityManagerFactory.close();
     }


     public static EntityManager createEntityManager() {
            if (entityManagerFactory == null) {
                throw new IllegalStateException("Context is not initialized yet.");
            }

            return entityManagerFactory.createEntityManager();
        }

}

我可以通过以下代码创建它,在我的测试类(它是一个arquillian测试类)中使用我的entityManager

EntityManager em = PersistenceListener.createEntityManager();
               em.getTransaction().begin();
                   em.createQuery("delete from Game").executeUpdate();
                   em.getTransaction().commit();

这是我的测试类的完整代码

    @RunWith(Arquillian.class)
    public class HibernateTestSample {

           @Deployment
           public static WebArchive createTestArchive()
           {
               MavenDependencyResolver resolver = DependencyResolvers.use(
                        MavenDependencyResolver.class).loadMetadataFromPom("pom.xml");

               WebArchive webArchive=  ShrinkWrap
                    .create(WebArchive.class, "ROOT.war")
                    .addClasses(CdiTestBean.class,HibernateListener.class,PersistenceListener.class)
                    .addAsLibraries(
                                resolver.artifact("org.jboss.weld.servlet:weld-servlet")
//                              .artifact("org.hibernate.javax.persistence:hibernate-jpa-2.0-api")
                                .artifact("org.apache.tomcat:tomcat-dbcp")
                                .artifact("org.hibernate:hibernate-entitymanager")
                                .artifact("org.hibernate:hibernate-validator")
                                .artifact("org.hibernate:hibernate-core")   
                                .artifact("com.h2database:h2")
                                .artifact("mysql:mysql-connector-java")
                                .resolveAs(GenericArchive.class))

                    .addAsWebInfResource(EmptyAsset.INSTANCE, "beans.xml")
                    .addAsWebInfResource("test-persistence.xml", "classes/META-INF/persistence.xml")
                    .addAsWebInfResource("hibernate.cfg.xml", "classes/hibernate.cfg.xml") 
//                  .addAsWebInfResource("context.xml", "classes/META-INF/context.xml")
                    .addAsManifestResource("context.xml", "context.xml")
                    .setWebXML("hibernate-web.xml");
              System.out.println(webArchive.toString(true));

              return webArchive;
           }


           @Test
           public void myTest()
                   throws Exception {                                                      

               EntityManager em = PersistenceListener.createEntityManager();
               em.getTransaction().begin();
                       em.createQuery("delete from Game").executeUpdate();
                   em.getTransaction().commit();
                  ...............
                      .......
                      ...


           }
    }

但我想将我的entityManager注入我的班级.我在另一篇文章 中读到我不能在我的班级中使用@PersistenceContext,因此我决定使用生产者注入我的实体管理器.但它对我不起作用,请告诉我这里我做错了什么(我是CDI的新手)

这是我的新ServletContextListener

public class PersistenceListener implements ServletContextListener {

     private static EntityManagerFactory entityManagerFactory;

     @Produces
     private EntityManager entityManager;

     public void contextInitialized(ServletContextEvent sce){
     ServletContext context = sce.getServletContext();
     entityManagerFactory = Persistence.createEntityManagerFactory("hibernate-test");
     createEntityManager();
     }

     public void contextDestroyed(ServletContextEvent sce) {
     entityManagerFactory.close();
     }


     public void createEntityManager() {
            if (entityManagerFactory == null) {
                throw new IllegalStateException("Context is not initialized yet.");
            }

            this.entityManager =  entityManagerFactory.createEntityManager();
        }

而且我正在我的测试类中注入

@Inject
private EntityManager em;

它是null

Answer 1

你需要@Produces的是你的createEntityManager方法，而不是字段。