dispatcher.forward（）产生HTTP 500

Question

Consider the hierarchy :

I moved my JSPs from WEB-INF to the src folder .However when I try to dispatcher.forward() , I get :

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
    controller.LoginPage.doPost(LoginPage.java:214)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.50 logs.

Apache Tomcat/7.0.50

The specified exception occurs in the lines :

 String addressPath = "/../view/admin/adminPage.jsp";
 RequestDispatcher dispatcher = request.getRequestDispatcher(addressPath);
 dispatcher.forward(request, response);

How can I fix the path ?

Thanks

Answer 1

The fact that your JSP is in a source folder seems to indicate that it will be placed in

/WEB-INF/classes/view/admin/

Which is really not where

String addressPath = "/../view/admin/adminPage.jsp";

is pointing it to.

getRequestDispatcher returns null if the Servlet container cannot return a RequestDispatcher for the given path.

JSPs shouldn't really be under /WEB-INF/classes . Put them in a dedicated folder like /WEB-INF/jsp/view and access them there.

You could then access it with

String addressPath = "/WEB-INF/jsp/view/admin/adminPage.jsp";