EntityManager.merge没有做任何事情

Question

我有一个用户实体:

@Entity
@Table( name = "bi_user" )
@SequenceGenerator( name = "USER_SEQ_GEN", sequenceName = "USER_SEQUENCE" )
public class User
        extends DataObjectAbstract<Long>
{
    private static final long serialVersionUID = -7870157016168718980L;

    /**
     * key for this instance. Should be managed by JPA provider.
     */
    @Id
    @GeneratedValue( strategy = GenerationType.SEQUENCE, generator = "USER_SEQ_GEN" )
    private Long key;

    /**
     * Username the user will use to login.  This should be an email address
     */
    @Column( nullable=false, unique=true)
    private String username;

    // etc. other columns and getters/setters
}

DataObjectAbstract是一个简单的@MappedSuperClass,具有jpa版本和equals/hashcode定义.

我有一个基本dao类,看起来像这样

public abstract class BaseDaoAbstract<T extends DataObject<K>, K extends Serializable>
        implements BaseDao<T, K>
{

    @PersistenceContext
    private EntityManager em;

    /**
     * Save a new entity. If the entity has already been persisted, then merge
     * should be called instead.
     * 
     * @param entity The transient entity to be saved.
     * @return The persisted transient entity.
     */
    @Transactional
    public T persist( T entity )
    {
        em.persist( entity );
        return entity;
    }

    /**
     * merge the changes in this detached object into the current persistent
     * context and write through to the database. This should be called to save
     * entities that already exist in the database.
     * 
     * @param entity The entity to be merged
     * @return The merged entity.
     */
    @Transactional
    public T merge( T entity )
    {
        return em.merge( entity );
    }

    // other methods like persist, delete, refresh, findByKey that all delegate to em.
}

我在web.xml中定义了OpenEntityManagerInView过滤器,如下所示

<filter>
    <filter-name>openEntityManagerInViewFilter</filter-name>
    <filter-class>
        org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter
    </filter-class>
    <init-param>
        <param-name>entityManagerFactoryBeanName</param-name>
        <param-value>biEmf</param-value>
    </init-param>
</filter>

<filter-mapping>
    <filter-name>openEntityManagerInViewFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

我最近升级到eclipselink 2.3.2和Spring 3.1,并使用aspectJ for Spring从CGLIB代理转换为Load Time Weaving,但我没有为eclipselink配置LTW.

问题出在这个代码中,它存在于Spring的ApplicationListener中,请参阅注释.

        User user = userService.findByKey(userDetails.getKey());

        // THIS MERGE NEVER WRITES THROUGH TO THE DATABASE.
        // THIS DOESN'T WORK AS PERSIST EITHER
        user = userService.merge( user.loginSuccess() );

user.loginSuccess只是设置了一些字段并返回this 我确定它正在通过代码,因为我得到了它周围的日志语句,我可以设置一个断点并遍历它.我的postgres日志没有显示任何流量进入合并的postgres.

我在没有问题的情况下保存其他所有内容,包括用户在更改密码时在其他位置,并且我知道此代码用于工作.这里有什么明显的错误吗？我是否错误地使用OpenEntityManagerInViewFilter？我是否需要使用@Transactional方法才能将实体视为托管？任何帮助表示赞赏.

更新 我按照prajeesh的建议尝试了冲洗.这是代码

@Transactional
public T merge( T entity )
{
    entity = em.merge( entity );
    em.flush();
    return entity;
}

在课堂上com.bi.data.我在我的春季app配置文件中有这个

<context:component-scan base-package="com.bi.controller,com.bi.data,com.bi.web" />

在我的弹簧配置中,我有

<context:load-time-weaver/>
<tx:annotation-driven mode="aspectj"/>    

使用如下所示的aop.xml:

<aspectj>
    <weaver>
        <!-- only weave classes in our application-specific packages -->
        <include within="com.bi..*"/>
    </weaver>
</aspectj>

我有一个

javax.persistence.TransactionRequiredException: 
Exception Description: No transaction is currently active

所以事情显然是错误的配置,但是什么？

更新2: 我恢复了我的更改以启用加载时间编织,现在合并通过有或没有刷新,但我仍然不明白LTW的问题是什么...

Answer 1

在尝试em.flush()后也em.merge().有时,EntityManager只是保留更改以便稍后更新.