File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
The moose likes Tomcat and the fly likes Embedded Tomcat servlet can't forward  request to JSP Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of Meteor in Action this week in the JavaScript forum!
JavaRanch » Java Forums » Products » Tomcat
Bookmark "Embedded Tomcat servlet can Watch "Embedded Tomcat servlet can New topic

Embedded Tomcat servlet can't forward request to JSP

Yuhong Qian

Joined: Jan 18, 2010
Posts: 5
Hi all,

I am using Embedded Tomcat7, servlet and jsp work very well separately, for example, http://localhost:8091/index.jsp or http://localhost:8091/hello work fine.

but when I use servlet to forward request to JSP, it can not get dispather for the jsp and throws java.lang.NullPointerException.

here is my code snippets:

tomcat.setPort(port); //defaults to 8080 if not set.
File docBase = new File(".");
Context ctxt = tomcat.addContext("/", docBase.getAbsolutePath());
the home page
jsp files are located at /webapps/manage
tomcat.addWebapp("", docBase.getAbsolutePath()+"/webapps/manage");
catch (ServletException e)
* HelloServlet prints a message
Tomcat.addServlet(ctxt, "hello", new HelloServlet("Hello World!"));
ctxt.addServletMapping("/hello", "hello");

* TestingServlet forward request to index.jsp
TestingServlet testingServlet = new TestingServlet();
Tomcat.addServlet(ctxt, "test", testingServlet);
ctxt.addServletMapping("/test/*", "test");

the TestingServlet :

String forward = "/index.jsp";
RequestDispatcher dispatcher = this.getServletContext().getRequestDispatcher(forward);
dispatcher.forward(request, response);

the result throws java.lang.NullPointerException at dispatcher.forward(request, response);

I checked and found the dispatcher is null, it seems that the JSP is not at the same context as Servlet.

How to solve this problem?


William Brogden
Author and all-around good cowpoke

Joined: Mar 22, 2000
Posts: 12931
If this was my problem the first thing I would do is log or print the String this statement creates:

I suspect it is meaningless.

I agree. Here's the link:
subject: Embedded Tomcat servlet can't forward request to JSP