POST request send JSON data Java HttpUrlConnection

curl, httpurlconnection, java, json, post

Solution

Your JSON is not correct. Instead of

JSONObject cred = new JSONObject();
JSONObject auth=new JSONObject();
JSONObject parent=new JSONObject();
cred.put("username","adm");
cred.put("password", "pwd");
auth.put("tenantName", "adm");
auth.put("passwordCredentials", cred.toString()); // <-- toString()
parent.put("auth", auth.toString());              // <-- toString()

OutputStreamWriter wr= new OutputStreamWriter(con.getOutputStream());
wr.write(parent.toString());

write

JSONObject cred = new JSONObject();
JSONObject auth=new JSONObject();
JSONObject parent=new JSONObject();
cred.put("username","adm");
cred.put("password", "pwd");
auth.put("tenantName", "adm");
auth.put("passwordCredentials", cred);
parent.put("auth", auth);

OutputStreamWriter wr= new OutputStreamWriter(con.getOutputStream());
wr.write(parent.toString());

So, the JSONObject.toString() should be called only once for the outer object.

Another thing (most probably not your problem, but I'd like to mention it):

To be sure not to run into encoding problems, you should specify the encoding, if it is not `UTF-8`:

con.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
con.setRequestProperty("Accept", "application/json");

// ...

OutputStream os = con.getOutputStream();
os.write(parent.toString().getBytes("UTF-8"));
os.close();

Problem

I have developed a Java code that convert the following cURL to java code using URL and HttpUrlConnection. the cURL is : ``` curl -i 'http://url.com' -X POST -H "Content-Type: application/json" -H "Accept: application/json" -d '{"auth": { "passwordCredentials": {"username": "adm", "password": "pwd"},"tenantName":"adm"}}' ``` I have written this code but it always gives HTTP code 400 bad request. I couldn't find what is missing. ``` String url="http://url.com"; URL object=new URL(url); HttpURLConnection con = (HttpURLConnection) object.openConnection(); con.setDoOutput(true); con.setDoInput(true); con.setRequestProperty("Content-Type", "application/json"); con.setRequestProperty("Accept", "application/json"); con.setRequestMethod("POST"); JSONObject cred = new JSONObject(); JSONObject auth = new JSONObject(); JSONObject parent = new JSONObject(); cred.put("username","adm"); cred.put("password", "pwd"); auth.put("tenantName", "adm"); auth.put("passwordCredentials", cred.toString()); parent.put("auth", auth.toString()); OutputStreamWriter wr = new OutputStreamWriter(con.getOutputStream()); wr.write(parent.toString()); wr.flush(); //display what returns the POST request StringBuilder sb = new StringBuilder(); int HttpResult = con.getResponseCode(); if (HttpResult == HttpURLConnection.HTTP_OK) { BufferedReader br = new BufferedReader( new InputStreamReader(con.getInputStream(), "utf-8")); String line = null; while ((line = br.readLine()) != null) { sb.append(line + "\n"); } br.close(); System.out.println("" + sb.toString()); } else { System.out.println(con.getResponseMessage()); } ```

Original source