javax.jcr.lock.LockException: Precondition Failed

Solution: While connecting to the JCR we may use something like below.
Session session = repository.login(new SimpleCredentials("admin", "admin".toCharArray()));
This statement may sometimes lead to an error in applications like AEM.
To avoid this we need to mention the default environemnt we are logging into.

So we should USE THIS INSTEAD.
Session session = repository.login( new SimpleCredentials("admin", "admin".toCharArray()),"crx.default");