JSP Servlet不执行doPost方法

Question

I have recently started programming in java and have been trying out some JSP development. I am trying to make a login page which uses the POST method to transfer data to the servlet. Here is my code:

<form method="POST" name ="loginForm"  action="userAuth">
            <input type="hidden" name="userAction" value="login">
            Username: <input type="text" name="txtUsername"> <br>
            Password    : <input type="password" name="txtPassword">
            <br><input type="submit"  value="Login">

</form>

The above code is from the initial login page.

The code below is from the userAuth.java file.

protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    processRequest(request, response);
    String userAction = request.getParameter("userAction");
    if (userAction.equals("Login")) {
    String userName = request.getParameter("txtUsername");
    String passWord = request.getParameter("txtPassword");

    if (userName.equals("hello") && passWord.equals("hello")) {
    response.sendRedirect("Homepage.jsp");
    }
    }
}

The problem I have is that when I input the correct username and password, the doPost method is not executed, so none of the redirects take place. Rather only the ProcessRequest method is executed which just displays the initial template to the web browser.

Thank you in advance.

PS I am using Apache Tomcat 8.0.27.0

Answer 1

I have solved the issue...

The issue was with the following line

<input type="hidden" name="userAction" value="**login**">

and the subsequent processing in the second block:

if (userAction.equals("**Login**")) {}

The login value didnt have an uppercase L.

Just changed this.

Answer 2

What does the processRequest() method do? If executes as you say then the server gives a response to the client and the remaining block of code does not execute. Have you tried to run without this function?

Answer 3

Hide the process request method.

Like this:

protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    //processRequest(request, response);
    String userAction = request.getParameter("userAction");
    if (userAction.equals("Login")) {
        String userName = request.getParameter("txtUsername");
        String passWord = request.getParameter("txtPassword");
    }
}