Tomcat and sequence of events

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pvsnmp@yahoo.com - 04 Dec 2005 15:32 GMT

Hi,
I have a web application with a number of servlets. I am using Tomcat.
I have configured a filter for the web application in its web.xml file.
The url pattern which the filter will match is /*. The application
servlets are present in ROOT directory, the default web application
path. I have also enabled the invoker servlet. It matches the default
url pattern /servlet/*.
Can someone explain the sequence of events that happen as a request
arrives for a servlet , with URL /servlet/xyz ? How does the filter
know where to hand the request to when it reaches
chain.doFilter(req,res) ? There are no other filters and none of the
servlets are defined in the web.xml file, so its the invoker servlet
which hands the request to servlets i guess. But how to the various
components know what is to be done next???

rgds,
Prashant

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Hiran Chaudhuri - 04 Dec 2005 23:46 GMT

> I have a web application with a number of servlets. I am using Tomcat.
> I have configured a filter for the web application in its web.xml file.
> The url pattern which the filter will match is /*. The application
> servlets are present in ROOT directory, the default web application
> path. I have also enabled the invoker servlet. It matches the default
> url pattern /servlet/*.

What do you mean by 'The application servlets are present in ROOT directory?

> Can someone explain the sequence of events that happen as a request
> arrives for a servlet , with URL /servlet/xyz ? How does the filter
> know where to hand the request to when it reaches
> chain.doFilter(req,res) ?

Tomcat fist checks the first part of the url to find the correct web
application (context).
Then it executes all the registered listeners, if their URL pattern matches.
Then it executes the servlet whose URL pattern matches.
Then it returns the response through the filters back to the browser.

> There are no other filters and none of the
> servlets are defined in the web.xml file, so its the invoker servlet
> which hands the request to servlets i guess. But how to the various
> components know what is to be done next???

That is what you specified in your web.xml. There are some more components,
such as valves. They are Tomcat internal and probably not interesting for
you.

Hiran

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pvsnmp@yahoo.com - 05 Dec 2005 00:18 GMT

>Tomcat fist checks the first part of the url to find the correct web
>application (context).
>Then it executes all the registered listeners, if their URL pattern matches.
>Then it executes the servlet whose URL pattern matches.
>Then it returns the response through the filters back to the browser.
>Hiran

Hi,
what abt request going through filter?? How does the filter know where
handout the request once its job is done ?? In my case i am not
defining the servlets in the web.xml file.

rgds,
Prashant

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Tomcat and sequence of events

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