Spring data mongodb optimistic lock

Spring data provides an optimistic lock implementation for mongodb:

The @Version annotation provides Syntax similar to that of JPA in the context of MongoDB and makes sure updates are only applied to documents with a matching version. Therefore,the actual value of the version property is added to the update query in such a way that the update does not have any effect if another operation altered the document in the meantime. In that case,an OptimisticLockingFailureException is thrown. The following example shows these features:

The @ version annotation is provided to identify the version. Saving, deleting and other operations will verify the version. If there is inconsistency, an optisticlockingfailureexception will be thrown

Let's take an example:

@Document
class Person {

  @Id String id;
  String firstname;
  String lastname;
  @Version Long version;
}

Person daenerys = template.insert(new Person("Daenerys"));                            (1)

Person tmp = template.findOne(query(where("id").is(daenerys.getId())),Person.class); (2)

daenerys.setLastname("Targaryen");
template.save(daenerys);                                                              (3)

template.save(tmp); // throws OptimisticLockingFailureException                       (4)

be careful: