Hi Ballu, Servlet chaining is a process of sending the output of one servlet to another servlet which is its input.i.e. the request from the client browser is send to the first servlet in the chain and the response from the last servlet in the chain is returned to the browser.In between the output from each servlet is piped to the next servlet and in the process u can midify the content to be sent at any given point of time till the response has not been sent back to the browser. Some of the uses of servlet chaining are: 1)One can quickly change the appearance of a page,a group mof pages,or a type of content. 2)Can embed custom tags in your page and have a servlet replace them with the Html content. 3)Can serve unsupported image types by converting them to the standard jpeg or gif type. I hope this might satisfy your query to some extent.bye.
Servlet Chaining was an old technique, implemented in Sun's Java Web Server, but not part of the Servlet Specification. Although it is theoretically useful, in practice the complications usually outweigh the advantages. The upcoming version 2.3 of the Servlet specification now supports "filters" which are a much mors powerful, flexible and controllable version of the same basic concept.