HttpServletRequest JSON parameter found null value in Servlet

Question

I'm using Servlet to handle request and response.

I have used following code to Servlet my request to sublet using webservice:

 JSONObject parans = new JSONObject();
    parans.put("commandid", "Enamu7l");
    System.out.println("parans = " + parans);        
    Client restClient = Client.create();
    WebResource webResource = restClient.resource("URL");
    ClientResponse resp = webResource.accept(MediaType.APPLICATION_JSON)
            .post(ClientResponse.class, parans.toJSONString());

Here is my servlet code to receive data.

 @Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    String commandid= request.getParameter("commandid");        
    System.out.println(commandid);       
}

commandid recieve null from webservice.

What to do in webservice to get data in servlet?

This is already answered https://stackoverflow.com/questions/14525982/getting-request-payload-from-post-request-in-java-servlet — ashok ankamreddy, May 15 '19 at 12:44

score 1 · Accepted Answer · edited May 15 '19 at 13:15

1

WebResource not sending the data as part of the url, so you can not use request.getParameter. The data is send as request body using the post method.Read the data using the reader.

       StringBuilder sb = new StringBuilder();
        while ((s = request.getReader().readLine()) != null) {
            sb.append(s);
        }
       JSONObject jSONObject = new JSONObject(sb.toString());

        System.out.println(jSONObject.getString("commandid"));

edited May 15 '19 at 13:15

star67

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answered May 15 '19 at 12:35

Srinivasan Sekar

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thanks for answer can you tell me sending the data as part of the url from WebResource – Enamul Haque May 15 '19 at 12:53
here https://stackoverflow.com/questions/2136119/using-the-jersey-client-to-do-a-post-operation – Srinivasan Sekar May 15 '19 at 12:55

Ori Marko · Answer 2 · 2019-05-15T12:44:20.370

0

You are sending JSON in request body, so you need to get it:

String json = request.getReader().lines().collect(Collectors.joining());

Convert to JSON:

JSONObject jsonObject = new JSONObject(json);

And get the value:

String value = jsonObject.getString("commandid");

edited May 15 '19 at 12:44

answered May 15 '19 at 12:39

Ori Marko

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HttpServletRequest JSON parameter found null value in Servlet

2 Answers2