How can I modify the 404 Error page, or other java exceptions

[Dan Agarlita]

You can modify the web.xml <error-page> directive:
<error-page>
            <error-code>404</error-code>
            <location>/error404.jsp</location>
</error-page>
.....
<error-page>
    <exception-type>java.lang.Exception</exception-type>
    <location>/error500.html</location>
</error-page>
....
The <error-page> tag is contained by <web-app> tags.
 
The order of tags in the web.xml is very important.
 
Best regards,
ADan