Thread Safety for Servlets

[rockies1]

I'm writing a servlet and I need to ensure it is thread safe.

How can I do that?

Thanks!

[CornedBee]

No generic way. Think about resources that one thread might access while another is modifying them. Make no assumptions about the order in which things happen. Then insert synchronization where necessary.

[Dillinger4]

Yes CornedBee is right. There is really no generic way to write multithreaded code that trys to tap single resource. What you want to be careful of though is miss-synchronization or deadlock.

But, synchronization is not always the best possible soultion to the problem of inconsistent behavior as a result of thread scheduling. One technique used ensure thread safety is to use local variables instead of fields wherever possible since they do not have synchronization problems. Every time a method is entered the JVM creates a completely new set of local variables. The variables are destroyed when the method exits. This means that there is no possible way for a local variable to be used in teo different threads. Every thread has its own set of local variables.