/**
* Check if the item is accessible for the given User and session. It is if there is no lock or
* the user owns the lock.
*
* @param item
* @return
*/
public boolean canAccess(User u, String sessionId, Lockable item) {
boolean result = true;
StatelessSession s = getSession();
Transaction tx = s.beginTransaction();
try {
Lock example = createLock(item);
Lock lock =
(Lock)
s.createCriteria(Lock.class)
.add(
Example.create(example)
.excludeProperty("httpSessionId")
.excludeProperty("userLogin")
.excludeProperty("name"))
.uniqueResult();
tx.commit();
if (lock != null) {
if ((lock.getUserLogin().equals(u.getLogin()))
&& (lock.getHttpSessionId().equals(sessionId))) result = true;
else result = false;
}
} catch (HibernateException he) {
log.debug("Lock problem in canAccess");
tx.rollback();
}
return result;
}
/**
* Aquire lock for given item or check that you still have it. This should be done before database
* objects are updated, not just before they are made persistent. It should not be done (Cannot be
* done) with objects that don't have a dbID yet.
*
* @param u
* @param sessionId
* @param item
* @return
*/
public boolean aquireLock(User u, String sessionId, Lockable item) {
boolean result = false;
StatelessSession s = getSession();
Transaction tx = s.beginTransaction();
if ((item == null) || (item.getDbID() == null)) throw new Error("Unlockable item");
try {
Lock lock = createLock(item);
lock.setUserLogin(u.getLogin());
lock.setHttpSessionId(sessionId);
log.debug("Aquire Lock\n" + lock.toString());
List<Lock> l =
s.createQuery("from Lock where objectId = :id and objectType = :type")
.setLong("id", lock.getObjectId())
.setString("type", lock.getObjectType())
.list();
if (l.size() == 0) {
s.insert(lock);
tx.commit();
result = true;
} else {
Lock lock2 = l.get(0);
if (lock2.getUserLogin().equals(lock.getUserLogin())
&& lock2.getHttpSessionId().equals(lock.getHttpSessionId())) result = true;
else result = false;
tx.commit();
}
} catch (HibernateException he) {
log.debug("lock aquire failed");
StringWriter sw = new StringWriter();
he.printStackTrace(new PrintWriter(sw));
log.error(sw.toString());
tx.rollback();
}
return result;
}
/**
* Releases the lock on the item (only for given user and session). Returns false if the lock
* didn't exist (or was owned by somebody else)
*
* @param u
* @param sessionId
* @param item
* @return
*/
public boolean releaseLock(User u, String sessionId, Lockable item) {
boolean result = false;
StatelessSession s = getSession();
Transaction tx = s.beginTransaction();
try {
Lock example = createLock(item);
example.setHttpSessionId(sessionId);
example.setUserLogin(u.getLogin());
Lock lock =
(Lock)
s.createCriteria(Lock.class)
.add(Example.create(example).excludeProperty("name"))
.uniqueResult();
s.delete(lock);
tx.commit();
result = true;
} catch (HibernateException he) {
log.debug("lock not released");
tx.rollback();
}
return result;
}
public List<Lock> findByUser(User u) {
StatelessSession s = getSession();
List<Lock> l =
s.createQuery("from Lock where userLogin = :login").setString("login", u.getLogin()).list();
return l;
}
