spring - 无法让 OpenEntityManagerInViewFilter 在 JBoss 6.1 中工作

Question

我正在尝试将打开 session View 行为添加到现有的纯 JPA 应用程序。在服务层使用 Spring 不是一个选择。我想将 View 包装在 Spring 的 OpenEntityManagerInViewFilter 中，而不必修改 EJB 层。

我没有运气让 OpenEntityManagerInViewFilter (Spring 3.2.2) 在 JBoss 6.1 中工作。过滤器肯定被调用，但我仍然在 View 中收到 LazyInitializationException。

过滤器和 session bean 使用 EntityManager 的不同实例(和类)。过滤器获取 org.hibernate.ejb.EntityManagerImpl ，而 session bean 获取 org.jboss.jpa.tx.TransactionScopedEntityManager 。我不确定 Spring 配置是造成这种情况的。

这是相关的代码/配置:

war/WEB-INF/classes/test.web.servlet.TestServlet

public class TestServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

@EJB
private ServiceLocal service;

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {

    long parentId = Long.parseLong(req.getParameter("parentId"));
    Parent parent = service.retrieveParent(parentId);

    // this call throws a LazyInitializationException
    // because parent.children.session is NULL
    parent.getChildren().iterator().next().getName();

    req.setAttribute("parent", parent);
    RequestDispatcher requestDispatcher = this.getServletContext().getRequestDispatcher("/WEB-INF/jsp/view.jsp");
    requestDispatcher.forward(req, resp);
}
}

ejb/test.ejb.session.ServiceBean

@Stateless
@TransactionAttribute(TransactionAttributeType.REQUIRED)
public class ServiceBean implements ServiceLocal, Service {

    @PersistenceContext(name="test")
    private EntityManager entityManager;

    @Override
    public Parent retrieveParent(Long parentId) {
        return entityManager.find(Parent.class, parentId);
    }
}

war/WEB-INF/web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
    http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">

<display-name>test-war</display-name>

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/spring.xml</param-value>
</context-param>

<filter>
    <filter-name>osiv-filter</filter-name>
    <filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
    <init-param>
        <param-name>flushMode</param-name>
        <param-value>AUTO</param-value>
    </init-param>
</filter>

<servlet>
    <servlet-name>test-servlet</servlet-name>
    <servlet-class>test.web.servlet.TestServlet</servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>test-servlet</servlet-name>
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

<filter-mapping>
    <filter-name>osiv-filter</filter-name>
    <servlet-name>test-servlet</servlet-name>
</filter-mapping>

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<listener>
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>

</web-app>

war/WEB-INF/spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN"
"http://www.springframework.org/dtd/spring-beans-2.0.dtd">
<beans>
<bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
    </property>
    <property name="persistenceUnitName" value="test" />
    <property name="jpaProperties">
        <props>
            <prop key="hibernate.transaction.manager_lookup_class">
                org.hibernate.transaction.JBossTransactionManagerLookup
            </prop>
        </props>
    </property>
</bean>
</beans>

ejb/META-INF/persistence.xml

<persistence
    xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">   
   <persistence-unit name="test" transaction-type="JTA">
      <provider>org.hibernate.ejb.HibernatePersistence</provider>
      <jta-data-source>java:/MSSQLDS</jta-data-source>
      <properties>
         <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect"/>
         <property name="hibernate.show_sql" value="false" />
         <property name="hibernate.format_sql" value="true" />
         <property name="hibernate.use_sql_comments" value="true" />
         <property name="jboss.entity.manager.factory.jndi.name" value="java:/testEntityManagerFactory" />
         <property name="jboss.entity.manager.jndi.name" value="java:/testEntityManager" />
      </properties>
   </persistence-unit>
</persistence>

Answer 1

我认为没有必要使用自定义 EntityManagerFactory 通过 JDNI 查找 EntityManagerFactory，该元素应该处理这一点。

我对你的设置进行了更多的考虑，我认为 spring OpenEntityManagerInViewFilter 不会为你工作。它将一个实体管理器绑定(bind)到当前线程，以便spring的事务管理代码可以重用它。问题是 spring 不处理服务 bean 的事务管理，因为这是由应用程序服务器处理的。应用服务器没有检测到Spring绑定(bind)到线程的实体管理器，并创建了另一个；导致 2 个不同的实例。

要使其工作，您应该在 spring 中定义服务 bean，以便 spring 处理事务管理，或者使用 jboss seam ( JBoss Seam: How to Open jpa/hibernate session in view )