EJB relationship no working -- The collection is obtained by another transa

Question

Hi guys,
I have two entity beans, and defined 1:n relationship following the proper procedure. However when I call the getter, I got following execption:
com.sap.engine.services.ejb.exceptions.BaseIllegalStateException: The collection is obtained by another transaction.
My code is following:
try {
    TimeStatusPK pk = new TimeStatusPK();
    pk.employeeID = employeeID;
    TimeStatusEntityLocal ts = tsHome.findByPrimaryKey(pk);
    Collection distribution = ts.getDistributionByStatus();
    Iterator it = distribution.iterator();
} catch (Exception e) {
    throw new TES_Exception(e);
exception occurs when calling distribution.iterator();  Looks like the return collection ( from the 1:n relationship) can not be touched because it's used by other object. I have no idea why this happens, searched in sdn, didn't find hte right answer. Please give me hints.
Thanks
Jayson

Answer 1

Jayson, mark your bean`s transaction type as "Bean":
<session>
<transaction-type>Bean</transaction-type>
</session>
and modify code like this:
try {
_context.getUserTransaction().begin();
TimeStatusPK pk = new TimeStatusPK();
pk.employeeID = employeeID;
TimeStatusEntityLocal ts = tsHome.findByPrimaryKey(pk);
Collection distribution = ts.getDistributionByStatus();
Iterator it = distribution.iterator();
_context.getUserTransaction().commit(); //SessionContext _context . set it in setSessionContext method
} catch (Exception e) {
try{
_context.getUserTransaction().rollback();
}catch(Exception e)
throw new TES_Exception(e);