How to configure welcome file list in web.xml

38
votes

I have this in my web.xml document. I am trying to have a welcome list so I dont need to type the path for the home page anymore. But everytime a clicked the application in my tomcat page it displays The requested resource is not available.

<listener>
    <listener-class>web.Init</listener-class>
</listener>

<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<servlet>
    <servlet-name>index</servlet-name>
    <servlet-class>web.IndexServlet</servlet-class>
</servlet>

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

My servlet for the jsp page 

package web;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;

public class IndexServlet extends HttpServlet
{
    private Logger logger = Logger.getLogger(this.getClass());
    private RequestDispatcher jsp;

    public void init(ServletConfig config) throws ServletException
    {
        ServletContext context = config.getServletContext();
        jsp = context.getRequestDispatcher("/WEB-INF/jsp/index.jsp");
    }

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
    {
        logger.debug("doGet()");
        jsp.forward(req, resp); 
    }
}

Why is that it is still not working?I still need to type the /index in my url...How to do this correctly?

6
jspservletsweb.xmlwelcome-file
what exactly are you entering in your URL , do you have an index.html page existing ?? - Hussain Akhtar Wahid 'Ghouri'
For example I clicked my webapp in tomcat manager. It will display the url localhost:8080/myProj at the very first. So I still need to type the index after that url to open my welcome page. What wring with this? - PeterJohn
your welcome file is [context root]/index.jsp The servlet will not be called for the welcome page. - DwB
well @BalusC has given the complete answer , just follow it - Hussain Akhtar Wahid 'Ghouri'

6 Answers

60
votes

You need to put the JSP file in /index.jsp instead of in /WEB-INF/jsp/index.jsp. This way the whole servlet is superflous by the way.

WebContent
 |-- META-INF
 |-- WEB-INF
 |    `-- web.xml
 `-- index.jsp

If you're absolutely positive that you need to invoke a servlet this strange way, then you should map it on an URL pattern of /index.jsp instead of /index. You only need to change it to get the request dispatcher from request instead of from config and get rid of the whole init() method.

In case you actually intend to have a "home page servlet" (and thus not a welcome file — which has an entirely different purpose; namely the default file which sould be served when a folder is being requested, which is thus not specifically the root folder), then you should be mapping the servlet on the empty string URL pattern.

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

See also Difference between / and /* in servlet mapping url pattern.

24
votes

I guess what you want is your index servlet to act as the welcome page, so change to:

<welcome-file-list>
   <welcome-file>index</welcome-file>
</welcome-file-list>

So that the index servlet will be used. Note, you'll need a servlet spec 2.4 container to be able to do this.

Note also, @BalusC gets my vote, for your index servlet on its own is superfluous.

4
votes

I saw a nice solution in this stackoverflow link that may help the readers of the defulat servlet handling issue by using the empty string URL pattern "" : 

@WebServlet("")

or

<servlet-mapping>
    <servlet-name>yourHomeServlet</servlet-name>
    <url-pattern></url-pattern> <!-- Yes, empty string! -->
</servlet-mapping>
2
votes

This is my way to setup Servlet as welcome page.

I share for whom concern.

web.xml

  <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    <servlet>
        <servlet-name>Demo</servlet-name>
        <servlet-class>servlet.Demo</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>Demo</servlet-name>
        <url-pattern></url-pattern>
    </servlet-mapping>

Servlet class

@WebServlet(name = "/demo")
public class Demo extends HttpServlet {
   public void doGet(HttpServletRequest req, HttpServletResponse res)
     throws ServletException, IOException  {
       RequestDispatcher rd = req.getRequestDispatcher("index.jsp");
   }
}
0
votes

I simply declared as below in web.xml file and Its working for me :

 <welcome-file-list>
    <welcome-file>/WEB-INF/jsps/index.jsp</welcome-file>
</welcome-file-list>

And NO html/jsp pages present in public directory except static resources(css, js, images). Now I can access my index page with URL like : http://localhost:8080/app/ Its calling /WEB-INF/jsps/index.jsp page. When hosted live in production the final URL looks like https://eisdigital.com/

-2
votes

Its based on from which file you are trying to access those files.

If it is in the same folder where your working project file is, then you can use just the file name. no need of path.

If it is in the another folder which is under the same parent folder of your working project file then you can use location like in the following /javascript/sample.js

In your example if you are trying to access your js file from your html file you can use the following location

../javascript/sample.js

the prefix../ will go to the parent folder of the file(Folder upward journey)