IllegalArgumentException on remove

[quake4ialdaris]

Hey guys, I'm trying to remove an entity. here's the code

Entity class:

@Entity
public class NewsEntity implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String title;
private String body;

public NewsEntity() {
}
public Long getId() {
return this.id;
}
public void setId(Long id) {
this.id = id;
}
@Override
public int hashCode() {
int hash = 0;
hash += (this.getId() != null ? this.getId().hashCode() : 0);
return hash;
}
@Override
public boolean equals(Object object)
{
if (!(object instanceof NewsEntity)) {
return false;
}
NewsEntity other = (NewsEntity)object;
if (this.getId() != other.getId() && (this.getId() == null || !this.getId().equals(other.getId()))) return false;
return true;
}
public String getTitle()
{
return title;
}
public void setTitle(String title)
{
this.title = title;
}
public String getBody()
{
return body;
}
public void setBody(String body)
{
this.body = body;
}
}

Here's my facade interface:

@Stateless
public class NewsEntityFacade implements NewsEntityFacadeLocal
{
@PersistenceContext
private EntityManager em;
private Logger logger = Logger.getLogger (this.getClass ());
public NewsEntityFacade ()
{
}
public void create (NewsEntity newsEntity)
{
em.persist (newsEntity);
}
public void edit (NewsEntity newsEntity)
{
em.merge (newsEntity);
}
public void destroy (NewsEntity newsEntity)
{
em.merge (newsEntity);
if( em.contains (newsEntity))
logger.info ("The Entity is attached to current Persistence Context");
else
logger.error ("Entity is not attached!");
/* throws exception */
em.remove (newsEntity);
}
public NewsEntity find (Object pk)
{
return (NewsEntity) em.find (NewsEntity.class, pk);
}
public List findAll ()
{
return em.createQuery ("select object(o) from NewsEntity as o").getResultList ();
}
}

Here is the code that looks up the proxy and performs the delete operation:

NewsEntityFacadeLocal newsEntFacLocal = null;
try
{
InitialContext ctx = new InitialContext ();
newsEntFacLocal = (NewsEntityFacadeLocal)ctx.lookup
("NewsApp/NewsEntityFacade/local");
}
catch(Exception ex)
{
logger.error ("Error in looking up NewsEntityFacadeLocal through");
logger.error ("JDNI context " +JNDI_NEWS_ENTITY_EJB);
ex.printStackTrace ();
}

//this record exists in data store
NewsEntity ne = newsEntFacLocal.find (new Long(3));
logger.info ("the entity found is: " + ne.toString ());
nef.destroy (ne);

When I try this code I get an exception in the destroy method:

javax.ejb.EJBException: java.lang.IllegalArgumentException: Removing a detached instance ejb.NewsEntity#3
org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:69)
org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:83)
org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77)
org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:102)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:47)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:211)
org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:79)
$Proxy286.destroy(Unknown Source)
web.DeleteMessage.processRequest(DeleteMessage.java:59)
web.DeleteMessage.doGet(DeleteMessage.java:123)
javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

I can't see why it wouldn't be attached as the EntityManager javadocs say that merge attaches the entity in the PersistenceContext.

thanks

alessandro ferrucci :)

[waynebaylor]

try changing the snippet:

public void destroy (NewsEntity newsEntity)
{
 em.merge (newsEntity);
 if( em.contains (newsEntity))
 logger.info ("The Entity is attached to current Persistence Context");
 else
 logger.error ("Entity is not attached!");
 /* throws exception */
 em.remove (newsEntity);
}

to something like:

public void destroy (NewsEntity newsEntity)
{
 NewsEntity managedEntity = em.merge (newsEntity);

 if( em.contains (managedEntity))
 {
 logger.info ("The Entity is attached to current Persistence Context");
 }
 else
 {
 logger.error ("Entity is not attached!");
 }

 /* throws exception */
 em.remove (managedEntity);
}

the problem is that you should be using the managed object returned by the EntityManager.merge() method.