Shared instance variable

[Ron Miller]

Can someone explain how multi-threading works in a container when there are multiple http requests all happening at the same time?

I want to save the servletConfig object in a private variable declared in HttpServlet but I am worried about whether one request can see the servletConfig of another request.

Thanks.

[Michael Angstadt]

Only one ServletConfig instance exists per servlet. So, because multiple threads run through a servlet (one thread per HTTP request), each thread will be accessing the same ServletConfig instance. Given ServletConfig's methods, do you think this will be a problem?

[Bear Bibeault]

Ron Miller wrote:I want to save the servletConfig object in a private variable declared in HttpServlet

Why? For what possible purpose?

[Ron Miller]

Bear Bibeault wrote:

Ron Miller wrote:I want to save the servletConfig object in a private variable declared in HttpServlet

Why? For what possible purpose?

I am studying for SCWCD that's why.

so if I declare a variable at servlet level the variable will be shared among all Http Requests? (and therefore not a good way to save info specific to that user, session, or request)

[Bear Bibeault]

Snippy is not a winning attitude. Knowing why someone wants to do something is usually key to figuring out the best way to accomplish something.

Moved to the SCWCD forum.

[Michael Angstadt]

Bear Bibeault wrote:

Ron Miller wrote:I want to save the servletConfig object in a private variable declared in HttpServlet

Why? For what possible purpose?

I think what Bear was getting at was that you don't need to store the ServletConfig in a variable. You can retrieve it anytime by calling getServletConfig().

Ron Miller wrote:so if I declare a variable at servlet level the variable will be shared among all Http Requests? (and therefore not a good way to save info specific to that user, session, or request)

Yes, you have to make sure your servlets are thread safe.

[Ron Miller]

Understood. Thanks.