Cache Problem, Please

Question

I have two different type objects, one refer another, using one to one mapping.
At first, I get the parent object, and then I also get the child object, using session.executeQuery, as you know, toplink will get the child object from the cache, as my database is modified by another program, so I use session.refreshObject(chindObject) to refresh the child object, and then I modify the child object and succuess, but when i get the parent object again, i find the childobject didnot be modified, and the parent pointer to childobject is the old address, but the toplink cache address of childobject has been changed.
I cant use session.refreshObject(parentObject) to refresh the parentObject, because I have many parent object. and my database may be modified by another program. so what can do?

Answer 1

Thank your responses, the following function is my adding and modifying function, please help me check it whether or it is right, thx!!!
And I used SoftCacheWeakIdentityMap. and whether all the searching function must use roq.dontCheckCache() to insure that the searching result is the latest data? if so, my cache is dirt cheap.
public static PersistenceObject getObjectByOid(Session session, Class clazz, String oid)
throws DomainServiceException {
String funcName = "getObjectByOid()";
try {
ReadObjectQuery roq = new ReadObjectQuery();
roq.setReferenceClass(clazz);
roq.setSelectionCriteria((new ExpressionBuilder()).get("oid").equal(oid));
roq.dontCheckCache(); //Use the Statement instead of session.refreshObject
PersistenceObject pObj = (PersistenceObject)session.executeQuery(roq);
integrator.logDebug(funcName, "session.executeQuery(): clazz: "+clazz+", oid:"+oid);
session.printIdentityMap(ProcessingMethod.class);
if (pObj != null){
//session.removeFromIdentityMap(pObj);
session.printIdentityMap(ProcessingMethod.class);
return pObj;
} catch (Throwable e) {
integrator.logError(funcName, "Input: clazz: "+clazz);
integrator.logError(funcName, "Input: oid: "+oid);
throw new DomainServiceException(e);
public static String addOrUpdateObject(Session session,PersistenceObject pObj, String userId)
throws DomainServiceException {
String funcName = "addOrUpdateObject()";
String oid = null;
Produce produce1 = (Produce)session.executeQuery("SelectyByOid", Produce.class, "51");
session.printIdentityMap(Produce.class);
if (pObj != null) {
// try to retrieve the corresponding object from DB.
if (pObj != null) {
//session.removeFromIdentityMap(pObj); // remove the pObj from identity map to make sure the object we get in the next line is from DB.
integrator.logDebug(funcName, "removeFromIdentityMap is called");
session.printIdentityMap(ProcessingMethod.class);
PersistenceObject pObjFromDB = (PersistenceObject) this.getObjectByOid(session, pObj.getClass(), pObj.getOid());
integrator.logDebug(funcName, "QueryService.getObjectByOid() is called");
// pObjFromDB = (PersistenceObject)session.refreshObject(pObjFromDB);
session.printIdentityMap(ProcessingMethod.class);
try {
UnitOfWork uow = session.acquireUnitOfWork(); // acquire the unit of work.
integrator.logDebug(funcName, "session.acquireUnitOfWork() is called");
uow.registerObject(pObjFromDB);
integrator.logDebug(funcName, "uow.registerObject() is called");
session.printIdentityMap(ProcessingMethod.class);
// merge the changes from pObj.
PersistenceObject pObjClone = (PersistenceObject) uow.mergeCloneWithReferences(pObj);
integrator.logDebug(funcName, "uow.mergeCloneWithReferences() is called");
updateObjHistory(uow, pObjClone, userId); // update the changelog.
integrator.logDebug(funcName, "updateObjHistory() is called");
uow.commit();
integrator.logDebug(funcName, "uow.commit() is called");
Produce produce2 = (Produce)session.executeQuery("SelectyByOid", Produce.class, "51");
oid = pObj.getOid();
} catch (DatabaseException dbException){
integrator.logError(funcName, dbException.getMessage());
dbException.printStackTrace();
if (dbException.getCause() instanceof SQLException) {
SQLException sqlException = (SQLException)dbException.getCause();
if (sqlException.getErrorCode() == 1){  // unique constraint violated.
throw new DuplicateRecordException(dbException);
} else {
throw new DomainServiceException(dbException);
return oid;