Why does GenericServlet implements ServletConfig?

[Faisal Ahmad]

I've beginner level of Servlet/JSP knowledge.

Is it right to say, a servlet that we write IS-A ServletConfig? Further, why a servlet has to implement ServletConfig interface? It gets an object of ServletConfig through its init method. Which means, a servlet HAS-A ServletConfig. In spite of this, why it implements ServletConfig interface?

[bhanu chowdary]

Faisal,

why a servlet has to implement ServletConfig interface?

Servlet Please go through the Servlet interface. I dont think there is any hard coded rule saying that a servlet has to implement ServletConfig. Moreover the servletConfig object is made by the container and passed to the init(servletConfig) in your servlet.

[Faisal Ahmad]

Servlet interface doesn't implement ServletConfig. But, why does GenericServlet? Already it HAS-A ServletConfig! In spite of this, what is the purpose of implementing a ServletConfig? I find it difficult to agree with this sentence: "A servlet IS-A ServletConfig". It's confusing.

[Faisal Ahmad]

Moderators!

I want to rename the title of this thread to "Why does GenericServlet implements ServletConfig?"

Could you please help? Thanks!

[Milan Sutaria]

Even I am preparing for SCWCD and am curious to know. If a servlet IS-A servletConfig why does the container has to pass a servletConfig to servlet:init(ServletConfig)?
(this is altogether a different question from the original)
Thanks for your thoughts

[Ulf Dittmer]

You need to differentiate between Servlet and GenericServlet. Servlet (which is an interface) does not implement ServletConfig, whereas GenericServlet (an actual class) does. It's perfectly possible (although very uncommon) for a servlet to implement Servlet instead of extending GenericServlet or HttpServlet.

As a bit of a history lesson (for those who have not been using the Servlet API for a dozen years or so...), GenericServlet originally did not implement ServletConfig; that was something that got added later as a convenience. So the ServletConfig object passed in via the init method was the one you had to use.

[Milan Sutaria]

Thanks Ulf