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Questions about ServletContext and ServletConfig

David Jones

Joined: Dec 26, 2003
Posts: 27
Hi all,

I have some questions about ServletContext and ServletConfig:

On HFSJ, page 151:
"By the time the servlet is running service methods, it's got a ServletConfig"

(Q1) Does this mean that ServletConfig can only be available in service() method (i.e. after init() method)?
(Q2) How about the ServletContext? Is ServletContext also ONLY be available in service() method (i.e. after init() method)?

On HFSJ, page 308:
"jspInit() called from the servlet's init() method, so by the time jspInit() runs there is a ServletConfig and ServletContext available to the servlet"

(Q3) As HFSJ mentioned, we can use ServletConfig and ServletContext in jspInit() method (i.e. can use them before _jspService() method, not like Servlet that only be avilable in service() method). Is this because the init() method of the generated servlet has already been executed and so ServletConfig and ServletContext are available in jspInit() method (since init() called jpsInit())?

singh santosh
Ranch Hand

Joined: Jan 13, 2006
Posts: 136
Let me try to clarify your doubts : there are two version init method:
1)init(ServletConfig config) in Servlet [life cycle method]
2)init() in GenericServlet (provide for u to override)

When the container intializes the servlet it calls init (1 version) .This init after successful initialization calls init (2 version).

So by the time init() is called ServletConfig is already avaialble.

ServletConfig holds the reference to ServletContext(offcource u can also get it through getServletContext() of GenericServlet class).

Same is true with the jsp also.

i hope i have clarified ur doubts.
Please let me know if i m wrong


I agree. Here's the link:
subject: Questions about ServletContext and ServletConfig
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