Object disappear

[phantom]

Good day,

Let me show you a real magic! But I don't know the secret... If you know it - please describe me! It's real problem for me...

1 Class:

package xxx.finders;

import org.jboss.seam.framework.EntityController;
import org.jboss.seam.log.Log;
import org.jboss.seam.annotations.Logger;
import org.jboss.seam.annotations.Transactional;
import xxx.Lecture;

import java.util.List;
import java.util.ArrayList;

public class AbstractFinder<K>
{
 private String query;

 private List<K> result;


 public final String getQuery()
 {
 return query;
 }

 public final void setQuery(String query)
 {
 this.query = query;
 }

 @Transactional
 public void search()
 {
 System.out.println("start search. This:"+this);
 this.result = searchResult();
 System.out.println("Cal result: "+result+" This:"+this);
 }

 @Transactional
 protected List<K> searchResult()
 {
 return new ArrayList<K>();
 }

 @Transactional
 public final List<K> getResult()
 {
 System.out.println("Start getResult. this:"+this);
 if(result==null)
 {
 System.out.println("searching"+this);
 search();
 System.out.println("Cal result: "+result+" This:"+this);
 }
 System.out.println("result: "+result+"this:"+this);
 return result;
 }
}

2 class

package xxx.finders;

import xxx.testtree.Test;

import java.util.List;
import java.util.ArrayList;

import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Logger;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Scope;
import org.jboss.seam.log.Log;
import org.jboss.seam.ScopeType;

import javax.persistence.EntityManager;

@Name("testFinder")
public class TestFinder extends AbstractFinder<Test>
{
 @In
 private EntityManager entityManager;

 @Logger
 private Log log;

 protected List<Test> searchResult()
 {
 log.info("Invoked!!!");
 String query = getQuery();
 if(query==null || query.equals(""))
 {
 List<Test> tests = (List<Test>)entityManager.createQuery("select object(t) from Test t order by t.title").getResultList();
 log.info("Tests: "+tests);
 return tests;
 }
 else
 {
 List<Test> ret = new ArrayList<Test>();
 String sql = "select object(t) from Test t where t.title like :query order by t.title";
 ret.addAll(entityManager.createQuery(sql).setParameter("query", "%"+query+"%").getResultList());
 sql = "select object(t) from Test t, Domain d where t.domain=d and d.title like :query order by t.title";
 ret.addAll(entityManager.createQuery(sql).setParameter("query", "%"+query+"%").getResultList());
 return ret;
 }
 }
}

Now the magic!

Externaly from JSF page I'm trying to get result property from 'testfinder' bean. And there I recieve null! But look to the logs:

2007-10-31 14:43:09,921 INFO [STDOUT] start search. This:xxx.finders.TestFinder@f09d3d
2007-10-31 14:43:09,921 INFO [xxx.finders.TestFinder] Invoked!!!
2007-10-31 14:43:09,921 DEBUG [org.hibernate.jdbc.AbstractBatcher] about to open PreparedStatement (open PreparedStatements: 0, globally: 0)
2007-10-31 14:43:09,921 DEBUG [org.hibernate.jdbc.ConnectionManager] opening JDBC connection
2007-10-31 14:43:09,921 DEBUG [org.hibernate.SQL] select test0_.test_id as test1_74_, test0_.title as title74_, test0_.content as content74_, test0_.author_id as author5_74_, test0_.domain_id as domain4_74_ from tests test0_ order by test0_.title
2007-10-31 14:43:09,921 DEBUG [org.hibernate.jdbc.AbstractBatcher] about to open ResultSet (open ResultSets: 0, globally: 0)
2007-10-31 14:43:09,921 DEBUG [org.hibernate.loader.Loader] result row: EntityKey[xxx.testtree.Test#1]
2007-10-31 14:43:09,921 DEBUG [org.hibernate.jdbc.AbstractBatcher] about to close ResultSet (open ResultSets: 1, globally: 1)
2007-10-31 14:43:09,921 DEBUG [org.hibernate.jdbc.AbstractBatcher] about to close PreparedStatement (open PreparedStatements: 1, globally: 1)
2007-10-31 14:43:09,921 DEBUG [org.hibernate.jdbc.ConnectionManager] aggressively releasing JDBC connection
2007-10-31 14:43:09,921 DEBUG [org.hibernate.jdbc.ConnectionManager] releasing JDBC connection [ (open PreparedStatements: 0, globally: 0) (open ResultSets: 0, globally: 0)]
2007-10-31 14:43:09,921 DEBUG [org.hibernate.engine.StatefulPersistenceContext] initializing non-lazy collections
2007-10-31 14:43:09,921 INFO [xxx.finders.TestFinder] Tests: [xxx.testtree.Test@1]
2007-10-31 14:43:09,921 INFO [STDOUT] Cal result: [xxx.testtree.Test@1] This:xxx.finders.TestFinder@f09d3d
2007-10-31 14:43:09,921 DEBUG [org.hibernate.ejb.AbstractEntityManagerImpl] Looking for a JTA transaction to join
2007-10-31 14:43:09,921 DEBUG [org.hibernate.ejb.AbstractEntityManagerImpl] Transaction already joined
2007-10-31 14:43:09,921 INFO [STDOUT] Cal result: null This:xxx.finders.TestFinder@f09d3d
2007-10-31 14:43:09,921 DEBUG [org.hibernate.ejb.AbstractEntityManagerImpl] Looking for a JTA transaction to join
2007-10-31 14:43:09,921 DEBUG [org.hibernate.ejb.AbstractEntityManagerImpl] Transaction already joined
2007-10-31 14:43:09,921 INFO [STDOUT] result: nullthis:xxx.finders.TestFinder@f09d3d

Most interesting (the first and the last line):

2007-10-31 14:43:09,921 INFO [STDOUT] Cal result: [xxx.testtree.Test@1] This:xxx.finders.TestFinder@f09d3d
2007-10-31 14:43:09,921 DEBUG [org.hibernate.ejb.AbstractEntityManagerImpl] Looking for a JTA transaction to join
2007-10-31 14:43:09,921 DEBUG [org.hibernate.ejb.AbstractEntityManagerImpl] Transaction already joined
2007-10-31 14:43:09,921 INFO [STDOUT] Cal result: null This:xxx.finders.TestFinder@f09d3d

That's mean that object disapear somewhere between method invokation! But where and why???

Please, help me!

[phantom]

Anser: Do not user FINAL methods!

In this case, the behavior is unpredictable.

[igx89]

I would conjecture that final methods would cause issues with all the proxying that Seam/EJB3 does; I remember that being a problem with Hibernate entities and all the proxying Hibernate does.

[igx89]

I wonder how easy it would be to make Seam throw an exception if it finds a Seam component with a final method...

[pmuir]

Fairly easy

for (java.lang.reflect.Method m : getClass().getMethods())
 {
 if (Modifier.isFinal(m.getModifiers()))
 {
 // throw exception
 }
 }

It just requires iterating over all methods of all components at startup. File a jira issue.