How to resolve OptimisticLockingFailureException?

The code that triggers the OptimisticLockingFailureException:

@Test
public void shouldIncrementUserTotalLikesByOne() throws IllegalArgumentException, UserNotFoundException { databuilderService.createAll(); User user = userService.findByEmail("[email protected]"); long numberOfLikeCount = user.getLikeCount(); userService.incrementUserTotalLikesByOne(user.getId()); userService.save(user); long numberOfUpdatedUpdatedCount = user.getLikeCount(); Assert.assertNotNull(numberOfUpdatedUpdatedCount); Assert.assertEquals(numberOfUpdatedUpdatedCount, numberOfLikeCount+1);
}

The exception occurs when UserService.save() is called:

org.springframework.dao.OptimisticLockingFailureException: Optimistic lock exception on saving entity:

3 Answers

I had a problem with my model. I added @Version annotation but by mistake there was wrong type of the field and the conversion process occurred during writing to MongoDB throwing OptimisticLockingFailureException exception.

The change @Version annotated field form long type to Long class resolved my problem:

import org.springframework.data.annotation.Version
@Version
private Long version

This blog article gives more details:

Optimistic locking exception means the object being persisted have already changed it's state in the database (some other transaction saved the object).

So, this is a domain specific problem. You have to decide what should be done.

Basically two options:

1. Present the error to the user.

2. Read the object from database and merge the changes. With this you should assume that you may lose the modifications done by other transactions.

I resolved OptimisticLockingFailureException which occurred while writing test case, actually I committed mistake of saving entity twice, userService.save(user); this statement is already written inuserService.incrementUserTotalLikesByOne(user.getId());