Mock Question about thread-safe

[Nicky Eng]

Web .com developers choose to avoid using SingleThreadModel, but wants to ensure data is updated in thread-safe manner.
which 2 support this design goal..? (choose 2)

A. Store the data in the local variable
B. store the data in an instance variable
C. store the data in the ServletContext object
D. Store the data in the ServletRequest object

what's the answer you think???

Store the data in local variable would make sense...then how about another one???

[Rizwan Mohammad]

Only local variables and request scope attributes are thread safe in servlet life cycle.
so my answers are
1)local variables &
2)request scoped attributes

[Vishnu Prakash]

Thread safe

* local variables
* request attributes

Not Thread safe

* instance variables
* class variables
* session attributes
* context attributes

Hope this is useful

[erwin jeffrey]

are static variables thread safe?