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Article:
  Java Web Applications
Subject:   HTTP Status 404 - /onjava/servlet/com.onjava.login
Date:   2007-09-25 03:00:06
From:   vikaschablani
Response to: HTTP Status 404 - /onjava/servlet/com.onjava.login

Below is the complete correct web.xml.
Do not forget <web-app> tag.
Restart the server.


The meaning of this is that in our login.jsp we have written action=servlet/com.onjava.login.
This same string "servlet/com.onjava.login" has to appear in web.xml in url-pattern. You can write any string but has to be same in jsp and in xml e.g. you can have string "Good", no problem.


The string between <servlet-mapping> and between
<servlet-name> has to be same, here it is login.
Then finally :) the string between <servlet-class> is the actual class part for your FILE login.class i.e. com.onjava.login. :)
web.xml->
-----------------------------------
<web-app>
<servlet>


<servlet-name>login</servlet-name>
<servlet-class>com.onjava.login</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>login</servlet-name>
<url-pattern>servlet/com.onjava.login</url-pattern>
</servlet-mapping>

</web-app>
-------------------------------------

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Showing messages 1 through 2 of 2.

  • HTTP Status 404 - /onjava/servlet/com.onjava.login
    2007-09-25 04:14:45  vikaschablani [View]

    One correction. In url patern there is a forward slash prefixed before the string. So if in jsp string was: action="servlet/com.onjava.login", in xml it will be
    <url-pattern>/servlet/com.onjava.login</url-pattern>

    web.xml->
    -----------------------------------
    <web-app>
    <servlet>


    <servlet-name>login</servlet-name>
    <servlet-class>com.onjava.login</servlet-class>
    </servlet>
    <servlet-mapping>
    <servlet-name>login</servlet-name>
    <url-pattern>/servlet/com.onjava.login</url-pattern>
    </servlet-mapping>

    </web-app>
    -------------------------------------
    • HTTP Status 404 - /onjava/servlet/com.onjava.login
      2009-12-09 06:12:59  BriGuyHcri [View]

      I just became a member today. And the truth is, it's because of you.

      I felt it was necessary so I could post a thank you for the post you made way back in 2007-09-25 at 4:14:45.

      You answered a question I had been grappling with regarding the O'Reilly OnJava Login example.

      You gave a FULL explanation and a SIMPLE way to remember the rule.

      Part of the problem with learning web programming is there is a lot of false starts, blind alleys and misdirections given because of out-dated examples and it's hard for newbies to wade through this muck. It's easy to get discouraged.

      JDK's change, as do 3rd party plugins with their unending versions, which makes some of the examples no longer applicable or unable to function without some modifications.

      Such is the case with the 2001 version of the O'Reilly's OnJava Login example, but you answered my question, and it now works. I can now continue my learning because of you.

      So thanks again.

      It matches the way I like to look at things using the KISS rule, so even 2 years later, you receive this Thanks.