req.getParameter returns null

Question

Im trying to get values from my request but it return null. What is the problem?

This is my form:

    <form class="register-form">
        <input class="name" type="text" placeholder="name"/>
        <input class="password" type="password" placeholder="password"/>
        <button id="register">create</button>
    </form>

My post method:

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
        String name = req.getParameter("name"); 
        if (Objects.isNull(projectService.getByName(name))) {
            logger.info("Registration new project " + name); //NAME == NULL ???
            String password = req.getParameter("password");
            int budget = Integer.parseInt(req.getParameter("budget"));

         ...

        resp.setContentType("text/plain");
        resp.setCharacterEncoding("UTF-8");
        resp.getWriter().write("Success");
    }

And JS part:

$(document).ready(function () {
    $("button#register").click(function () {
        var name = $("form.register-form input.name").val();
        var password = $("form.register-form input.password").val();
        if (name == '' || password == '') {
            alert("Please fill all fields...!!!!!!");
        }  else {
            var projectRegistration = {
                projectName: name,
                projectPassword: password
            };
            $.post("registration", projectRegistration, function (data) {
                if (data === 'Success') {
                    $("form")[0].reset();
                }
            });
        }
    });
});

Im using Tomcat ver 8.5.56

There was a typo in your JS code. The if condition has an extra || operator. — Carlos Bazilio, Jul 02 '20 at 20:40

score 1 · Answer 1 · answered Jul 02 '20 at 20:45

1

The root cause of the problem is that you are not passing any parameter with the name, name because you do not have an input field with the name, name.

Replace

<input class="name" type="text" placeholder="name"/>

with

<input class="name" type="text" placeholder="name" name="name"/>

answered Jul 02 '20 at 20:45

Arvind Kumar Avinash

71,965
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I think that my answer and yours are together the cause, don't you think? The request is made by JS code, which passes the projectRegistration object. This object doesn't have a field name also. – Carlos Bazilio Jul 02 '20 at 21:41
@CarlosBazilio - You are right. Thanks for asking OP to consider this answer as well. – Arvind Kumar Avinash Jul 03 '20 at 08:33

score 0 · Accepted Answer · answered Jul 02 '20 at 20:39

0

At JS code you are building an object projectRegistration which is passed to post request. This object has keys projectName and projectPassword which should be used inside the servlet:

String name = req.getParameter("projectName");

Hope it helps.

answered Jul 02 '20 at 20:39

Carlos Bazilio

830
9
20

Thanks a lot! It works fo me! – Andrii Vytrykhovskyi Jul 02 '20 at 21:37
1

Great! But I think you should also consider the other answer too, since the name attribute in the inputs are also missing. – Carlos Bazilio Jul 02 '20 at 21:43
@CarlosBazilio - You have a heart of gold. – Arvind Kumar Avinash Jul 03 '20 at 08:32

req.getParameter returns null

2 Answers2