questions

[Anne Sullivan]

I have a questions regarding the SCJP exam:

1.
Can a static method be synchronized? If so, what is being locked
since there is no this reference?

2.
I thought one object has only one lock. Is that
not true?

[Pooja Jindal]

1.) Yes static methods can be syncronised.
they are synchronized on the class
eg-syncronized(<class name>

2.)Yes each object has only one lock

[Raghavan Muthu]

Originally posted by Anne Sullivan:
I have a questions regarding the SCJP exam:

1.
Can a static method be synchronized? If so, what is being locked
since there is no this reference?

From Kathy Sierra's and Bert Bate's SCJP book,

Static
methods can be synchronized. There is only one copy of the static data you�re trying
to protect, so you only need one lock per class to synchronize static methods�a lock
for the whole class. There is such a lock; every class loaded in Java has a corresponding
instance of java.lang.Class representing that class. It�s that java.lang.Class instance
whose lock is used to protect the static methods of the class (if they�re synchronized).

Hope this clears!