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

Can anyone tell me the advantage of the synchronized method over the synchronized block with an example? Thanks.

There is not a clear advantage of using synchronized method over the block.

Perhaps the only one ( but I wouldn't call it an advantage ) is you don't need to include the object reference this.

Method:

public synchronized void method() { // blocks "this" from here.... 
    ...
    ...
    ...
} // to here

Block:

public void method() { 
    synchronized( this ) { // blocks "this" from here .... 
        ....
        ....
        ....
    }  // to here...
}

See? No advantage at all.

Blocks do have advantages over methods though, mostly in flexibility because you can use another object as lock whereas syncing the method would lock the entire object.

Compare:

// locks the whole object
... 
private synchronized void someInputRelatedWork() {
    ... 
}
private synchronized void someOutputRelatedWork() {
    ... 
}

vs.

// Using specific locks
Object inputLock = new Object();
Object outputLock = new Object();

private void someInputRelatedWork() {
    synchronized(inputLock) { 
        ... 
    } 
}
private void someOutputRelatedWork() {
    synchronized(outputLock) { 
        ... 
    }
}

Also if the method grows you can still keep the synchronized section separated:

 private void method() {
     ... code here
     ... code here
     ... code here
    synchronized( lock ) { 
        ... very few lines of code here
    }
     ... code here
     ... code here
     ... code here
     ... code here
}