Java Servlet doPost() returning null from Postman

Question

I am doing a simple Java Servlet POST request without using any HTML and only using Postman. And the response from getParameter() is always null.

Here is the servlet:

@WebServlet("/api/form")
public class FormServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        String orderNumber = req.getParameter("testString");
        System.out.println(orderNumber);
        resp.getWriter().print(orderNumber);
    }
}

And a picture with responses and how I am doing it:

EDIT

As was commented by Mukesh Verma.

All I had to do was add @MultipartConfig Annotation and I got the data.

@npinti How would that help? That's not what's sent in a form request. — Dave Newton, Sep 28 '18 at 15:21
Try using @MultipartConfig Annotation. It handles form-data mime type. — Mukesh Verma, Sep 28 '18 at 15:34

score 1 · Answer 1 · answered Sep 28 '18 at 15:19

1

This is not how method getParameter works. As stated in this question, you should call the servlet with the following URL:

http://localhost:8080/api/form?testString=test

answered Sep 28 '18 at 15:19

Lorelorelore

3,335
8
29
40

It does return "test", but is there no way to get it working with Postman's form-data? – Richard Sep 28 '18 at 15:20
1

Try changing Postman's radiobutton from `form-data` to `x-www-form-urlencoded` – Lorelorelore Sep 28 '18 at 15:24
It doesn't have to be `getParameter()` but is there a way to get the data from the request? – Richard Sep 28 '18 at 15:24
It still returns null – Richard Sep 28 '18 at 15:24
@kataroty Try `getParameterMap()` to see if you get anything – Andreas Sep 28 '18 at 15:26
Take a look here: https://stackoverflow.com/questions/5222/accessing-post-variables-using-java-servlets set Postman to `form-data` and access the using `getParametersMap` – Lorelorelore Sep 28 '18 at 15:27
Try using @MultipartConfig. – Mukesh Verma Sep 28 '18 at 15:35

score 1 · Answer 2 · answered Sep 28 '18 at 15:54

1

Try using @MultipartConfig Annotation. It handles form-data mime type.

answered Sep 28 '18 at 15:54

Mukesh Verma

524
5
9

score 0 · Answer 3 · answered Jan 21 '19 at 11:39

0

Changing Postman's radiobutton from form-data to x-www-form-urlencoded also does the trick and I am able to get the data.

answered Jan 21 '19 at 11:39

Siva

170
1
3
11

Java Servlet doPost() returning null from Postman

3 Answers3