为什么这个request.getParameter（）不起作用？

Question

I have a simple login page (login.jsp) and I'm checking it against a database to verify user credentials. This is just for testing, not for making an actual site.

In the verification servlet where the values are checked against the DB values, if there is not a match I do a

response.getRedirect("login.jsp?loginfailed=true");

This, obviously, sends me to

localhost:8080/blahblahblahblah/login.jsp?loginfailed=true

which is what I want. But then, in the jsp file, I do

<%
    if(request.getParameter("loginfailed") == "true")
    {
        out.println("login failed");
    }
%>

I'm well aware that I should replace this with JSTL , it's just easier for me to use scriptlets at first for control flow and I change them out once the logic works.

I just don't know why it is not working right now. What am I doing wrong?

Basically when credentials DO match DB values, it redirects to a success page. But if they don't, it redirects back to login.jsp with a URL param, and I want to print some text that says the login failed so the user doesn't have to look at the url to see that.

Answer 1

your redirection should be in this way. response.sendRedirect(request.getContextPath()+"/login.jsp?loginfailed=true");