Question

In Java an Object itself can act as a lock for guarding its own state . This convention is used in many built in classes like Vector and other synchronized collections where every method is synchronized and thus guarded by the intrinsic lock of the object itself . Is this good or bad ? Please give reasons also .

Answer 1

Pros

• It’s simple.
• You can control the lock externally.

Cons

• It breaks encapuslation.
• You can’t change its locking behaviour without changing its implied contract.

For the most part, it doesn’t matter unless you are developing an API which will be widely used. So while using synchronised(this) is not ideal, it is simple.