检索servlet中的上一个页面路径？

Question

I am trying to keep the user trace if he has no privileges then return him back to page from where he request (previous page path) with message. In doGet() when I try to get request url by using request.getPathInfo() it gives null in jboss console.

My doGet source is following from servlet:

protected void doGet(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException {
    if (!validateUserSession(request, response)) {
        return;
    }

    String pathTrace = request.getPathInfo();
    System.out.println("Request is comming from : " + pathTrace); // null

    loadNavigation(request, response);

    ServletContext context = getServletContext();
    RequestDispatcher rd = context
            .getRequestDispatcher("/jsp/admin_account/InviteUser.jsp");
    rd.forward(request, response);
}

Answer 1

Get it from the request headers.

String pathTrace = request.getHeader("referer");
System.out.println("Request is comming from : " + pathTrace);

Answer 2

From JavaDocs , getPathInfo may return NULL

public java.lang.String getPathInfo()

Returns any extra path information associated with the URL the client sent when it made this request. The extra path information follows the servlet path but precedes the query string. This method returns null if there was no extra path information.

Use below API

public java.lang.String getServletPath()

Returns the part of this request's URL that calls the servlet. This includes either the servlet name or a path to the servlet, but does not include any extra path information or a query string. Same as the value of the CGI variable SCRIPT_NAME. Returns: a String containing the name or path of the servlet being called, as specified in the request URL, decoded.

EDIT: Since you need passing servlet URL

Add referrer_url as one more param in the passing servlet and pass the value to other servlet where you are trying to get the path