url-pattern in web.xml not recognising multiple url

Question

I have web.xml like this :

  <servlet>
    <servlet-name>MyDisplayCourse</servlet-name>
    <servlet-class>edu.itn.controller.MyDisplayCourse</servlet-class>
</servlet>

and servlet-mapping for the servlet is:

 <servlet-mapping>
    <servlet-name>MyDisplayCourse</servlet-name>
     <url-pattern>/admin/displaystudent</url-pattern>    
    <url-pattern>/displaystudent</url-pattern>    
 </servlet-mapping>

When i use :

 <url-pattern>/displaystudent</url-pattern>

It finds the servlet MyDisplayCourse, but when i use append /admin/

 <url-pattern>/admin/displaystudent</url-pattern>

This shows 404 error code in my web app. Can someone help me why doesn't support url like /admin/displaystudent but supports only single url like /displaystudent only.

Possible duplicate of [many url-pattern for the same servlet](http://stackoverflow.com/questions/8995353/many-url-pattern-for-the-same-servlet) — Jon Sampson, Feb 23 '17 at 04:02
this is not the question i am asking. i want to use /admin/displaystudent instead of /displaystudent only. — Bishal Gautam, Feb 23 '17 at 05:03
How do you access your application? Can you provide the URL as well? — N00b Pr0grammer, Feb 25 '17 at 03:51
Both the urls should work fine. Can you create a sample project which can recreate the issue ? — s7vr, Feb 25 '17 at 08:16
@N00bPr0grammer localhost:8080/practiceweb/admin/displaystudent — Bishal Gautam, Feb 25 '17 at 08:32
I don't think there is enough information in the post to tell what issue it is. May be it is something else that is causing this issue.Like I said please try to create a sample project demonstrating the issue. — s7vr, Feb 25 '17 at 08:35
I need a http://stackoverflow.com/help/mcve. Also any error you see in server logs — s7vr, Feb 25 '17 at 08:39
https://github.com/gautamvishal00/demoproject/tree/master/PracticeWeb see the project here. — Bishal Gautam, Feb 25 '17 at 09:01
Thanks for providing the project. I'm positive that `@WebServlet` annotation on your controller class is conflicting with `web.xml` url pattterns. Can you try removing the `@WebServlet` annotation and then try accessing the urls ?. — s7vr, Feb 25 '17 at 10:46
no it is not. @Veeram , it is mapping error. Checked those things like hundred times now. — Bishal Gautam, Feb 25 '17 at 10:49

score 1 · Accepted Answer · answered Feb 25 '17 at 19:22

There is no issue with url-pattern

the issue is with your code in DisplayStudent.java

replace

RequestDispatcher rd=request.getRequestDispatcher("StudentTable.jsp");

with

RequestDispatcher rd=request.getRequestDispatcher("/StudentTable.jsp");

ServletRequestSpec

If the path begins with a "/" it is interpreted as relative to the current context root

otherwise it will concatinate with relative path in your case '/admin/StudentTable.jsp'

following code is implementation of getRequestDispatcher

@Override
public RequestDispatcher getRequestDispatcher(final String path) {
String realPath;
 if (path.startsWith("/")) {
    realPath = path;
 } else {
    String current = exchange.getRelativePath();
    int lastSlash = current.lastIndexOf("/");
    if (lastSlash != -1) {
        current = current.substring(0, lastSlash + 1);
    }
    realPath = CanonicalPathUtils.canonicalize(current + path);
 }
 return new RequestDispatcherImpl(realPath, servletContext);
}

url-pattern in web.xml not recognising multiple url

1 Answers1