Question/issue regarding querying for uncommited objects in Toplink...

Question

Hi, was hoping to get some insight into this problem we are encoutering…
We have this scenario were we are creating a folder hierarchy (using Toplink)
1. a parent folder is created
2. child elements are created (in the same transaction as step 1),
3. we need to lookup the parent folder and assign it as the parent
of these child elements
4. end the transaction and commit all data
In our system we control access to objects by appending a filter to the selection criteria, so we end up with SQL like this example
(The t2 stuff is the authorization lookup part of the query.) ;
SELECT t0.ID, t0.CLASS_NAME, t0.DESCRIPTION, t0.EDITABLE,
t0.DATE_MODIFIED, t0.DATE_CREATED,
t0.MODIFIED_BY, t0.ACL_ID, t0.NAME, t0.CREATED_BY,
t0.TYPE_ID, t0.WKSP_ID, t1.ID, t1.LINK_SRC_PATH,
t1.ABSOLUTE_PATH, t1.MIME_TYPE, t1.FSIZE,
t1.CONTENT_PATH, t1.PARENT_ID
FROM XDOOBJECT t0, ALL_OBJECT_PRIVILEGES t2,
ARCHIVEOBJECT t1
WHERE ((((t1.ABSOLUTE_PATH = '/favorites/twatson2')
AND ((t1.ID = t2.xdoobject_id)
AND ((t2.user_id = 'twatson2')
AND (bitand(t2.privilege, 2) = 2))))
AND (t1.ID = t0.ID))
AND (t0.CLASS_NAME = 'oracle.xdo.server.repository.model.Archivable'))
When creating new objects we also create the authorization lookup record (which is inserted into a different table.) I can see all the objects are registered in the UOW identity map.
Basically, the issue is that this scenario all occurs in a single transaction and when querying for the newly created parent folder, if the authorization filter is appended to the query, the parent is not found. If I remove the authorization filter then the parent is found correctly. Or if I break this up into separate transactions and commit after each insert, then the parent is found correctly.
I use the conformResultsInUnitOfWork attribute on the queries.
This is related to an earlier thread I have in this discussion forum;
Nested UnitOfWork and reading newly created objects...
Thanks for any help you can provide,
-Tim

Answer 1

Hi Doug, we add the authorization filter directly in the application code as the query is getting set up.
Here are some code examples; 1) the first is the code to create new object in the system, followed by 2) the code to create a new authorization lookup record (which also uses the first code to do the actual Toplink insert), then 3) an example of a read query where the authorization filter is appended to the Expression and after that 4) several helper methods.
I hope this is of some use as it's difficult to show the complete flow in a simple example.
1)
// create new object example
public Object DataAccess.createObject(....
Object result = null;
boolean inTx = true;
UnitOfWork uow = null;
try
SessionContext sc = mScm.getCurrentSessionContext();
uow = TLTransactionManager.getActiveTransaction(sc.getUserId());
if (uow == null)
Session session = TLSessionFactory.getSession();
uow = session.acquireUnitOfWork();
inTx = false;
Object oclone = (Object) uow.registerObject(object);
uow.assignSequenceNumbers();
if (oclone instanceof BaseObject)
BaseObject boclone = (BaseObject)oclone;
Date now = new Date();
boclone.setCreated(now);
boclone.setModified(now);
boclone.setModifiedBy(sc.getUserId());
boclone.setCreatedBy(sc.getUserId());
uow.printRegisteredObjects();
uow.validateObjectSpace();
if (inTx == false) uow.commit();
//just temp, see above
if (true == authorizer.requiresCheck(oclone))
authorizer.grantPrivilege(oclone);
result = oclone;
2)
// Authorizer.grantPrivilege method
public void grantPrivilege(Object object) throws DataAccessException
if (requiresCheck(object) == false)
throw new DataAccessException(
"Object does not implement Securable interface.");
Securable so = (Securable)object;
ModulePrivilege[] privs = so.getDefinedPrivileges();
BigInteger pmask = new BigInteger("0");
for (int i = 0; i < privs.length; i++)
BigInteger pv = PrivilegeManagerFactory.getPrivilegeValue(privs);
pmask = pmask.add(pv);
SessionContext sc = mScm.getCurrentSessionContext();
// the authorization lookup record
ObjectUserPrivilege oup = new ObjectUserPrivilege();
oup.setAclId(so.getAclId());
oup.setPrivileges(pmask);
oup.setUserId(sc.getUserId());
oup.setXdoObjectId(so.getId());
try
// this recurses back to the code snippet from above
mDataAccess.createObject(oup, this);
catch (DataAccessException dae) {
Object[] args = {dae.getClass().toString(), dae.getMessage()};
logger.severe(MessageFormat.format(EXCEPTION_MESSAGE, args));
throw new DataAccessException("Failed to grant object privilege.", dae);
3)
// example Query code
Object object = null;
ExpressionBuilder eb = new ExpressionBuilder();
Expression exp = eb.get(queryKeys[0]).equal(keyValues[0]);
for (int i = 1; i < queryKeys.length; i++)
exp = exp.and(eb.get(queryKeys[i]).equal(keyValues[i]));
// check if need to add authorization filter
if (authorizer.requiresCheck(domainClass) == true)
// this is where the authorization filter is appended to query
exp = exp.and(appendReadFilter());
ReadObjectQuery query = new ReadObjectQuery(domainClass, exp);
SessionContext sc = mScm.getCurrentSessionContext();
if (TLTransactionManager.isInTransaction(sc.getUserId()))
// part of a larger transaction scenario
query.conformResultsInUnitOfWork();
else
// not part of a transaction
query.refreshIdentityMapResult();
query.cascadePrivateParts();
Session session = getSession();
object = session.executeQuery(query);
4)
// builds the authorzation filter
private Expression appendReadFilter()
ExpressionBuilder eb = new ExpressionBuilder();
Expression exp1 = eb.getTable("ALL_OBJECT_PRIVILEGES").getField("xdoobject_id");
Expression exp2 = eb.getTable("ALL_OBJECT_PRIVILEGES").getField("user_id");
Expression exp3 = eb.getTable("ALL_OBJECT_PRIVILEGES").getField("privilege");
Vector args = new Vector();
args.add(READ_PRIVILEGE_VALUE);
Expression exp4 =
exp3.getFunctionWithArguments("bitand",args).equal(READ_PRIVILEGE_VALUE);
SessionContext sc = mScm.getCurrentSessionContext();
return eb.get("ID").equal(exp1).and(exp2.equal(sc.getUserId()).and(exp4));
// helper to get Toplink Session
private Session getSession() throws DataAccessException
SessionContext sc = mScm.getCurrentSessionContext();
Session session = TLTransactionManager.getActiveTransaction(sc.getUserId());
if (session == null)
session = TLSessionFactory.getSession();
return session;
// method of TLTransactionManager, provides easy access to TLSession
// which handles Toplink Sessions and is a singleton
public static UnitOfWork getActiveTransaction(String userId)
throws DataAccessException
TLSession tls = TLSession.getInstance();
return tls.getTransaction(userId);
// the TLSession method, returns the active transaction (UOW)
// or null if none
public UnitOfWork getTransaction(String uid) {
UnitOfWork uow = null;
UowWrapper uw = (UowWrapper)mTransactions.get(uid);
if (uw != null) {
uow = uw.getUow();
return uow;
Thanks!
-Tim