Contains

The contains() method can be used to determine whether an entity instance is managed in the current persistence context.

The contains method returns true:

• If the entity has been retrieved from the database or has been returned by getReference, and has not been removed or detached.
• If the entity instance is new, and the persist method has been called on the entity or the persist operation has been cascaded to it.

The contains method returns false:

• If the instance is detached.
• If the remove method has been called on the entity, or the remove operation has been cascaded to it.
• If the instance is new, and the persist method has not been called on the entity or the persist operation has not been cascaded to it.