how many times is destroy()called in servlet

how many times is destroy() called in servlet?

destroy() method is called :
1.) when on the whole, web application is undeployed from Servlet Container...
2.) When particular Servlet detail is deleted from web.xml...

Container calls only once , but you can call any number of time !

Arun Giridharan wrote:Container calls only once ...

That's generally true, but the container is free to take a servlet out of service and put it back into service at any time it chooses. So you can't rely on it only happening once.

...but you can call any number of time !

That's true, but app code should never call the lifecycle methods (like init and destroy); that's for the container to do.

Arun Giridharan wrote:Container calls only once , but you can call any number of time !

Repeated for emphasis: don't do this! Ever. Ever.

Ram Narayan.M wrote:2.) When particular Servlet detail is deleted from web.xml...

It has nothing at all to do with web.xml.

Tim Moores wrote:

Arun Giridharan wrote:Container calls only once ...

That's generally true, but the container is free to take a servlet out of service and put it back into service at any time it chooses. So you can't rely on it only happening once.

Can you explain on this , quite misleading.

Arun Giridharan wrote:

Tim Moores wrote:

Arun Giridharan wrote:Container calls only once ...

That's generally true, but the container is free to take a servlet out of service and put it back into service at any time it chooses. So you can't rely on it only happening once.

Can you explain on this , quite misleading.

It is not misleading at all. It is, in fact, quite accurate.

Essentially, it can happen up to once per servlet instance.

Bear Bibeault wrote:Essentially, it can happen up to once per servlet instance.

that's true.

Really a nice explanation. Thanks Tim and Bibeault.