why we need init method in servlet

every extended servlet having constructor for initialisation of resouces
then why we need init method servlet

1. The servlet container needs a no-args constructor to create an instance from the class named in web.xml - therefore constructors with arguments are never used in a real servlet container - if you want to make one for testing outside a servlet container, feel free.
2. A servlet instance needs to know the ServletConfig information before it can work in a servlet container therefore there must be an init(ServletConfig conf) method.

Bill

ok,
but we are having the init() method without arguments what about
that

There are two init methods.
The one you've listed is a convenience method that gets called by init(config).

This is why it's important to call:
super.init(config) if you override init(config).

see my conversation from first to last
there is not init() [with out arguments ] method what will happend
already we have constructor and init(ServletConfig con)

in place of not u assume no

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bear
JavaRanch Sheriff

Originally posted by kumar kotha:
in place of not u assume no

you can almost always able to edit your post. used the pencil-pad icon to do so.

Look at the Servlet interface in the JavaDocs - you will see that only one init method is required in a servlet, the one using ServletConfig. The servlet container ALWAYS calls this method after creating an instance and before any requests are processed.

NOW - look at the GenericServlet abstract class JavaDocs - you will see that this class has added the init() as "a convenience method" along with many other methods. The init( config ) method in GenericServlet calls the init() method - as described in the JavaDocs.

Anybody serious about servlet programming should become familiar with the JavaDocs for the servlet related packages and the formal specification of the API.

Bill

Good answers