配置能够在Seam 3中@Inject EntityManager

Question

在项目中,我使用Seam 3,我注射有问题EntityManager与@Inject注解.我很确定有某种配置可以确保EnityManager知道PersistenceUnit要使用哪种配置.例如,EJB你可以输入:

@PersistenceContext(unitName="MY_PERSISTENCE_UNIT_NAME")
private EntityManager eManager;

在persistence.xml文件中配置了哪个持久性单元.这是我的伪配置:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
    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_2_0.xsd">

    <persistence-unit name="MY_PERSISTENCE_UNIT_NAME" transaction-type="JTA">

        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <jta-data-source>java:jboss/TimeReportDS</jta-data-source>
        <mapping-file>META-INF/orm.xml</mapping-file> 

        <class>....</class>
        <class>....</class>
        <class>....</class>

        <properties>

            <property name="jboss.entity.manager.factory.jndi.name"
                value="java:/modelEntityManagerFactory" />

            <!-- PostgreSQL Configuration File -->
            <property name="hibernate.connection.driver_class" value="org.postgresql.Driver" />
            <property name="hibernate.connection.password" value="password" />
            <property name="hibernate.connection.url" value="jdbc:postgresql://192.168.2.125:5432/t_report" />
            <property name="hibernate.connection.username" value="username" />

            <!-- Specifying DB Driver, providing hibernate cfg lookup
                 and providing transaction manager configuration -->
            <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="hibernate.transaction.factory_class" value="org.hibernate.transaction.JTATransactionFactory"/>
            <property name="hibernate.transaction.manager_lookup_class"
                value="org.hibernate.transaction.JBossTransactionManagerLookup" />
            <property name="hibernate.archive.autodetection" value="class" />

            <!-- Useful configuration during development - developer can see structured SQL queries -->
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="false" />

        </properties>
    </persistence-unit>
</persistence>  

我已经阅读了一些关于Seam 2的文章,但是配置是components.xml通过添加以下内容在文件中进行的:

<persistence:managed-persistence-context
        name="entityManager" auto-create="true" persistence-unit-jndi-name="java:/modelEntityManagerFactory" />

在<components>标签内.Seam 2的下一步是添加:

<property name="jboss.entity.manager.factory.jndi.name"
                value="java:/modelEntityManagerFactory" />

在里面 persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence ...>
    <persistence-unit name="MY_PERSISTENCE_UNIT_NAME" ...>
        ...
        <properties>
            ...

            <property name="jboss.entity.manager.factory.jndi.name"
                value="java:/modelEntityManagerFactory" />

        </properties>
    </persistence-unit>
</persistence>

但它缝在Seam 3没有文件components.xml.此外unitName,@Inject注释中没有用于指定持久性单元的属性.

所以请帮我配置我的项目,以便我可以使用网络上的许多示例中显示的@Injectwith EntityManager.

我使用Postgres数据库和JBoss AS 7.

编辑:添加一个例子.我没有EntityManager在Entity课堂上使用.

@Named("validateReportAction")
@SessionScoped
public class ValidateReportAction extends ReportAction implements Serializable {

    private static final long serialVersionUID = -2456544897212149335L;

    @Inject
    private EntityManager em;
...
}  

在这里,@Inject我得到Eclipse" No bean is eligible for injection to the injection point [JSR-299 §5.2.1]"的 警告

如果我使用@Inject了一些豆子被标记为Entity的@Inject精品工程.

Answer 1

您可以在CDI bean上使用@PersistenceContext.它不一定是EJB.

如果由于某种原因你想使用@Inject,你必须做更多的工作.@Inject不知道EntityManager; 它只能注入其他托管bean.令人高兴的是,有一个简单的解决方法 - 使用一个充当简单蹦床的生产者方法.

@ApplicationScoped
public class EntityManagerProducer {

    @PersistenceContext
    private EntityManager entityManager;

    @Produces
    @RequestScoped
    public EntityManager getEntityManager {
        return entityManager;
    }

    public void closeEntityManager(@Disposes EntityManager em) {
        if (em != null && em.getTransaction().isActive()) {
            em.getTransaction().rollback();
        }
        if (em != null && em.isOpen()) {
            em.close();
        }
    }

}

您现在可以使用@Inject注入EntityManager.注入的EntityManager将是RequestScoped,而EntityManagerProducer是ApplicationScoped.此外,必须关闭entityManager.