| [eclipselink-users] Recovering from optimistic lock exception |
I would like to automatically handle optimistic lock exceptions through user defined merge policies however while testing my logic in a simple test case I encounter an exception when committing the transaction. If a merge fails are you not able to attempt to merge again in the same transaction? javax.persistence.RollbackException: Transaction rolled back because transaction was set to RollbackOnly. at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commitInternal(EntityTransactionImpl.java:92) at org.eclipse.persistence.internal.jpa.transaction.EntityTransactionImpl.commit(EntityTransactionImpl.java:63) EntityManager em = createEntityManager(); try { em.getTransaction().begin(); mergeInstance(em, entity_b); em.getTransaction().commit(); } catch (Exception p) { Assert.fail(p.getMessage()); } finally { if (em.isOpen()) { em.close(); } } private void mergeInstance(EntityManager em, InstanceImpl entity) { int retryCount = 2; int cnt = 0; InstanceImpl localEntity = entity; while (cnt < retryCount) { try { localEntity = em.merge(localEntity); return; } catch (OptimisticLockException e) { cnt++; System.out.println("\n>>> Optimistic Lock Exception encountered, retry number "+cnt); String sql = "SELECT e FROM InstanceImpl e WHERE e.uuid IN ('" //$NON-NLS-1$ + localEntity.getUUID().toString() + "')"; //$NON-NLS-1$ Query query = em.createQuery(sql); query.setHint(QueryHints.CACHE_USAGE, CacheUsage.DoNotCheckCache); // Merge local data with latest repository data InstanceImpl repoEntity = (InstanceImpl)query.getSingleResult(); localEntity.setOptLock(repoEntity.getOptLock()); } } } --
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