EntityManager.merge not doing anything

Question

I have a User entity:

@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
}

Where DataObjectAbstract is a simple @MappedSuperClass that has a jpa version and equals/hashcode definition.

I have a base dao class that looks like this

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.
}

I have defined the OpenEntityManagerInView filter in web.xml as follows

<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>

I recently upgrade to eclipselink 2.3.2 and Spring 3.1 and converted from CGLIB proxies to Load Time Weaving with aspectJ for Spring but I did not configure LTW for eclipselink.

The problem is in this code which lives in a spring ApplicationListener, see comments.

        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 just sets some fields and returns this I'm certain it's getting through the code because I get log statements around it and I can set a breakpoint and walk through it. My postgres log doesn't show any traffic getting to postgres for the merge.

I am saving other stuff all over the place without issue, including users in another location when they change their password, and I know this code used to work. Is there something obviously amiss here? Am I using the OpenEntityManagerInViewFilter incorrectly? Should I need to be in a @Transactional method in order for the entities to be considered managed? Any help is appreciated.

Update I tried the flush as suggested by prajeesh. Here's the code

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

in a class in com.bi.data. I have this in my spring app config file

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

In my spring configuration I have

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

with an aop.xml that looks like this:

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

and I got a

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

So something is obviously misconfigured, but what?

Update 2: I reverted my changes to enable load time weaving and now the merge goes through with or without the flush, but I still don't understand what the problem is with LTW...

Answer 1

Try the em.flush() also after the em.merge(). Sometimes the EntityManager just keeps the the changes for updating later.