When to use ThreadLocal

[Ashish]

When should i use ThreadLocal? What would I acheive from that? Is there any scenerios where I should use ThreadLocal?

[oregon]

You usually use a ThreadLocal when you have several threads that needs to have its own local data.

[ingle.anil]

let suppose you program is system and there may be may subsystems, how can you pass message between these subsystems ..lots of way in which you can do this ..one way is global variable.
think as subsystems is thread and that thread calls/calls lots of new threads ( sub subsystems ) in this sort of scenario you create ThreadLocal variable in parent class and use that in sub sub systems.

[danielstoner]

Sorry ingle.anil but that doesn't make sense. ThreadLocal is not global variable at all. It is storage for a specificthread. Another thread cannot access that data. ThreadLocal can help you write code that is concurrency aware and needs to associate data with each execution thread. Managing DB statements can be a good example.