Proxy issue ?

[sgodbert]

Hi,

I am not sure if this the correct thread for my post. Please redirect me if I'm wrong.

I have the following piece of code, which does not give the result I expected :

...
 
GlobalStatus newGlobalStatus  = currentStatusService.computeGlobalStatus(xxx, yyy);
		
GlobalStatus previousGlobalStatus = currentStatusService.getGlobalStatus(zzz);

LOGGER.warn("1 newGlobalStatus.getId(): " + newGlobalStatus.getId());
LOGGER.warn("1 previousGlobalStatus.getId(): " + previousGlobalStatus.getId());

if(previousGlobalStatus==null || (previousGlobalStatus.getId()!=newGlobalStatus.getId()))
{
  if(previousGlobalStatus==null ){LOGGER.warn("previousGlobalStatus : null " );}
  if(previousGlobalStatus!=null && previousGlobalStatus.getId()!=newGlobalStatus.getId())
  {
      LOGGER.warn("previousGlobalStatus.getId()!=newGlobalStatus.getId()" );
  }

LOGGER.warn("2 previousGlobalStatus.getId() : " + previousGlobalStatus.getId() );
LOGGER.warn("2 newGlobalStatus.getId() : " + newGlobalStatus.getId() );
....
}

GlobalStatus is an hibernate bean that looks like this :

@Entity
@Table(name="GLOBAL_STATUS")
public class GlobalStatus {

  private Integer id;
  ...

  @Id
  @GeneratedValue(strategy=GenerationType.AUTO)
  public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
  
  ...
}

The methods currentStatusService.computeGlobalStatus() and currentStatusService.getGlobalStatus() request objects from the database using HQL. Like this :

public GlobalStatus getByKnownCardholderCurrentStatus(
			KnownCardholderCurrentStatus knownCardholderCurrentStatus) {
		
	StringBuilder stringQuery = new StringBuilder("");
	stringQuery.append(" SELECT globalStatus ");
	stringQuery.append(" FROM KnownCardholderCurrentStatus knownCardholderCurrentStatus ");
	stringQuery.append(" JOIN knownCardholderCurrentStatus.globalStatus globalStatus ");
	stringQuery.append(" WHERE knownCardholderCurrentStatus = :knownCardholderCurrentStatus ");
		
	Query query = sessionFactory.getCurrentSession().createQuery(stringQuery.toString());
	query.setParameter("knownCardholderCurrentStatus", knownCardholderCurrentStatus);
				
	return (GlobalStatus) query.uniqueResult();
}

When I execute the piece of code I get :

1 newGlobalStatus.getId(): 130
1 previousGlobalStatus.getId(): 130 
previousGlobalStatus.getId()!=newGlobalStatus.getId()
2 previousGlobalStatus.getId() : 130 
2 newGlobalStatus.getId() : 130

This shouldn't be happening...

Am I really tired and I am missing something obvious ? I still don't understand why is this happening. I am suspecting that it is caused by the proxy mechanism of Spring.

Any idea ?

Sylvain

[Marten Deinum]

You are comparing Integer objects and not int objects... new iNteger(30) = new integer(30) will return false... You need to use equals instead of = (or switch to int instead of Integer).

[sgodbert]

Thanks Marten, you are right.

I have always thought that auto-unboxing would occur when comparing 2 Integer objects. In fact it does not, it still compares the object references. The tricky thing is that the reference is the same if you create the Integer from the same boxed primitive :

Integer a = 20;
Integer b = 20;

System.out.println(a == b); //gives true

Integer c = new Integer(20);
Integer d = new Integer(20);

System.out.println(c == d); //gives false

I wonder how come I've never come across this beginner issue before.

That is funny when something is unexplained, we always go looking at the wrong place...

My post was really out-of-scope for this thread, as I was suspecting.

Thanks again for your help

Sylvain