Is there an advantage to use a Synchronized Method instead of a Synchronized Block?

Question

Can any one tell me the advantage of synchronized method over synchronized block with an example?

Answer 1

Important note on using the synchronized block: careful what you use as lock object!

The code snippet from user2277816 above illustrates this point in that a reference to a string literal is used as locking object. Realize that string literals are automatically interned in Java and you should begin to see the problem: every piece of code that synchronizes on the literal "lock", shares the same lock! This can easily lead to deadlocks with completely unrelated pieces of code.

It is not just String objects that you need to be careful with. Boxed primitives are also a danger, since autoboxing and the valueOf methods can reuse the same objects, depending on the value.

For more information see: https://www.securecoding.cert.org/confluence/display/java/LCK01-J.+Do+not+synchronize+on+objects+that+may+be+reused