Question

1)My environment is web application, I develop servlet to receive request.

A) In some block/method i want to control concurrent to not greater than 5
B) if there are 5 request in that block , the new coming must wait up to 60 second then throws error
C) if there are sleep/waiting request more then 30, the 31th request will be throwed an error

How I do this?

2)(Optional Question) from above I have to distribute control logic to all clustered host.
I plan to use hazelcast to share the control logic (e.g. current counter)

I see they provide BlockingQueue & ExectorService but I have no idea how to use in my case.
Please recommend if you have idea.

Answer 1

For A take a look at this: http://java.sun.com/j2se/1.5.0/docs/api/java/util/concurrent/Semaphore.html

For B take a look at Object.wait() and Object.notify()

C should be easy if you have A and B.