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static variable in a servlet

 
Ranch Hand
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Defining a static variable in a servlet can be useful in any scenerio?

Static variable are shared between instances but servlet has only one instance at a time (except clustered environment).

So I guess, except clustered environment, no body will use static member in servlet.

Is it right?

Thanks.
 
Greenhorn
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A very good question.I agree with your expalnation.Because only one instance will be created in servlet.So there is no use os Static varibales.
 
Ranch Hand
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Not always some J2EE server allows you to create pool for SingleThreadedServlet. For example in WebLogic you can configure to have more than one instance of the same servlet.
 
Sheriff
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You can also create multiple servlet instances from the same class by adding new servlet entries in your deployment descriptor.
I this case both servlets (even though they have different names) will share the same static variables.
 
ankur rathi
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Thanks All.
Nice answers.
 
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Also even with one servlet instance running a static variable is fine if it is thread safe.
 
Sheriff
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I use static variables in servlets all the time -- mostly for "constants".
 
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