cannot post parameter using httpurlconnection

Question

I use this tutorial to use HttpRULConnection to post info to server. Following is my code:

    String urlParameters = "username=" + username + "&regid=" + uuid;
    byte[] postData = urlParameters.getBytes( StandardCharsets.UTF_8 );

    try {
        URL url = new URL(server_uri);

        try {
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setRequestMethod("POST");
            conn.setRequestProperty("X-latitude", "40.7439905");
            conn.setRequestProperty("X-longitude", "-74.0323626");
            conn.setRequestProperty("charset", "utf-8");
            conn.setRequestProperty( "Content-Length", Integer.toString( postData.length ));
            conn.setUseCaches(false);

            int responseCode = conn.getResponseCode();
            Log.d("responseCode", responseCode + "");

            //send register request
            OutputStream wr = conn.getOutputStream();
            wr.write(postData);
            wr.flush();
            wr.close();

            //get response
            .........

            Log.d("registration_id", registerResponse.registration_id+"");

        } catch (IOException e) {
            e.printStackTrace();
        }
    } catch (MalformedURLException e) {
        e.printStackTrace();
    }

However, the LogCat said: content-length promised 54 bytes, but received 0 . It means that the parameters did not post successfully. And in my server, it also display: username=null, uuid=null

thanks in advance.

I would recommend to use Volley. If you want I can give you help. — Mikheil Zhghenti, Mar 13 '16 at 00:10
@greenapps No. after post, the server will return a json stream — sydridgm, Mar 13 '16 at 02:15
Man, look at your code. You request the response code before writing the post data. — greenapps, Mar 13 '16 at 07:06
@greenapps you mean `int responseCode = conn.getResponseCode();` request the response? could you write a answer for this question. thanks — sydridgm, Mar 13 '16 at 14:46

Mikheil Zhghenti · Answer 1 · 2016-03-13T22:45:31.213

This is how to send data to the server by Volley.

First go to Gradle and import library. Paste this into dependencies
`compile 'me.neavo:volley:2014.12.09'

    private Map<String, String> data;

`

 StringRequest stringRequest = new StringRequest(Request.Method.POST, SERVER_URL,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(context, error.toString(), Toast.LENGTH_LONG).show();
                }
            }) {
        @Override
        protected Map<String, String> getParams() {
            // puts the data (which goes to server)
            data.put("name",user_name);
            data.put("gender",user_gender);

            data.toString();
            return data;
        }
    };
    RequestQueue requestQueue = Volley.newRequestQueue(context);
    requestQueue.add(stringRequest);

This example sends POST, but you can change it and use Request.Method.GET. SERVER_URLis where you send your data. data is a Map where you can put your parameters.

cannot post parameter using httpurlconnection

1 Answers1