what the difference between using synchronized keyword and lock

Question

Java 5 introduce the lock method. Any pros and cons using lock compared to synchronized keyword?

Answer 1

'synchronize' will lock any resources accessed within the method. 'lock' allows you more granularity, and control (e.g. only locking some resources, or locking only if a certain condition is met, for example).

There's a pretty good code sample near the top of this link: http://download.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/locks/Lock.html

Answer 2

The java.util.concurrent locks give you more control on what and when to lock. You can still use the synchronized keyword if it fits your needs (e.g. if you need per-instance / per-class synchronization)

Answer 3

See the difference between synchronized keyword and lock