about path prefix mappings, default mappings

[rick collette]

Hi,
Could anyone explain path prefix mappings and default mappings by giving some examples? Thanks in advance.

[Madhav Lakkapragada]

Could you please specify a context in which you encountered this. Would make it easy for me to come up with an example, to relate to what you are looking for.
regds.
- madhav

[rick collette]

<servlet-mapping>
  <servlet-name>myServlet</servlet-name>
  <url-pattern>/sth.html</url-pattern>
</servlet-mapping>

For the above case, now we can use: http://localhost/sth.html
to map to myServlet.
If we want to use path prefix mapping, we
have to do sth like this:

<servlet-mapping>
  <servlet-name>myServlet</servlet-name>
  <url-pattern>/sth/*</url-pattern>
</servlet-mapping>

Does that mean we can map to myServlet like this now?
http://localhost/sth/whatever
If we want to use default mapping, we have to do sth like this:

<servlet-mapping>
  <servlet-name>myServlet</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

The above code will ID the default servlet for web-app. How do we define our default servlet? and how to use url to locate myServlet in this case?
Thanks in advance.
rick
[ April 11, 2002: Message edited by: Peter den Haan ]

[Peter den Haan]

<servlet-mapping>
  <servlet-name>myServlet</servlet-name>
  <url-pattern>/sth/*</url-pattern>
</servlet-mapping>

Does that mean we can map to myServlet like this now?
http://localhost/sth/whatever

Yes. This facility is used a lot to implement virtual directories: e.g. a request for http://localhost/sth/secret/mydocument.doc would fire the "sth" servlet. This servlet then examines the extra path info ("/secret/mydocument.doc") and can for example retrieve the document from a database. That way, you can make the contents of a database (or a JNDI tree or an XML file or...) look like a set of directories and documents on a web server.

<servlet-mapping>
  <servlet-name>myServlet</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

[...] How do we define our default servlet? and how to use url to locate myServlet in this case?

I don't quite understand the question? You define the default servlet as usual - by defining a servlet called "myServlet". Any request to the server will invoke the default servlet, unless there is a more specific servlet mapping for that request.
- Peter
[Yuk. I don't know what happened to the quoting - hopefully this will be better]
[ April 11, 2002: Message edited by: Peter den Haan ]

[rick collette]

Gracias, Peter:
We depend on gurus like Peter, Clark, Carl, Alex, madhav, etc (sorry that I cannot remember all).
Folks, never take it for granted. I have not passed the exam yet, but I know these good folks have saved my time in my slow world. Merci.
[ April 11, 2002: Message edited by: rick collette ]

[Axel Janssen]

Originally posted by Peter den Haan:
Yes. This facility is used a lot to implement virtual directories: e.g. a request for http://localhost/sth/secret/mydocument.doc would fire the "sth" servlet. This servlet then examines the extra path info ("/secret/mydocument.doc") and can for example retrieve the document from a database. That way, you can make the contents of a database (or a JNDI tree or an XML file or...) look like a set of directories and documents on a web server.
[/qb]

Don't miss this one.
[ April 11, 2002: Message edited by: Axel Janssen ]