[java] Pass Hidden parameters using response.sendRedirect()

How would I pass hidden parameters? I want to call a page (test.jsp) but also pass 2 hidden parameters like a post.

response.sendRedirect("/content/test.jsp");

Generally, you cannot send a POST request using sendRedirect() method. You can use RequestDispatcher to forward() requests with parameters within the same web application, same context.

RequestDispatcher dispatcher = servletContext().getRequestDispatcher("test.jsp");
dispatcher.forward(request, response);

The HTTP spec states that all redirects must be in the form of a GET (or HEAD). You can consider encrypting your query string parameters if security is an issue. Another way is you can POST to the target by having a hidden form with method POST and submitting it with javascript when the page is loaded.

To send a variable value through URL in response.sendRedirect(). I have used it for one variable, you can also use it for two variable by proper concatenation.

String value="xyz";

response.sendRedirect("/content/test.jsp?var="+value);

Using session, I successfully passed a parameter (name) from servlet #1 to servlet #2, using response.sendRedirect in servlet #1. Servlet #1 code:

protected void doPost(HttpServletRequest request, HttpServletResponse response) {
    String name = request.getParameter("name");
    String password = request.getParameter("password");
    ...
    request.getSession().setAttribute("name", name);
    response.sendRedirect("/todo.do");

In Servlet #2, you don't need to get name back. It's already connected to the session. You could do String name = (String) request.getSession().getAttribute("name"); ---but you don't need this.

If Servlet #2 calls a JSP, you can show name this way on the JSP webpage:

<h1>Welcome ${name}</h1>