BufferedReader UTF-8 BOM - php

Question

I have a method in Java where I try to get one integer (user id) through a POST json request, this is the method:
public static Integer getUserIdOwnerOfMsg(Message msg) {
Integer idUser = null;
try {
JSONObject jsonObject = new JSONObject();
jsonObject.put("textMsg", msg.getTextMsg());
jsonObject.put("hourMsg", msg.getHourMsg());
List list = new LinkedList();
list.addAll(Arrays.asList(jsonObject));
String jsonString = list.toString();
String urlStr = SERVER_PATH + "getUserIdOwnerOfMsgJSON.php";
URL url = new URL(urlStr);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", "your user agent");
con.setRequestProperty("Accept-Language", "sp,SP;q=0.5");
//con.setRequestProperty("Content-Type", "text/html; charset=UTF-8");
String urlParameters = "json=" + jsonString;
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
InputStream instream;
int status = con.getResponseCode();
if (status != HttpURLConnection.HTTP_OK)
instream = con.getErrorStream();
else
instream = con.getInputStream();
BufferedReader in = new BufferedReader(new InputStreamReader(instream, "UTF-8")); // ISO-8859-1
in.mark(1);
if(in.read() != 0xFEFF)
in.reset();
String inputLine;
StringBuilder response = new StringBuilder();
while((inputLine = in.readLine()) != null)
response.append(inputLine);
in.close();
JSONObject object = new JSONObject(response.toString());
Boolean correct = object.getBoolean("correct");
if (correct) {
idUser = object.getInt("id");
}
} catch (Exception e) {
e.printStackTrace();
}
return idUser;
}
The problem is that the response contains a UTF-8 BOM character, on postman the result it's ok and I can see the id: ({"id":"7","correct":true})
But debugging on android studio I got the value "" or null for idUser, I don't know why, I've tried so many ways to resolve this problem without succeed.
Also on the php server side I've executed echo mb_detect_encoding($idUsuario); and I got ASCII encoding in case that could help to find the solution.
Any help will be apreciated, thank you!

Answer 1

So finally I got the solution, I post it here in case someone have the same issue as me, the problem was with the parameters of the JSON, because they included UTF-8 characters like €, so instead of reading the parameters like this:
wr.writeBytes (urlParameters);
I have to do this:
byte[] buf = urlParameters.getBytes("UTF-8");
wr.write(buf, 0, buf.length);
I post also the complete function in case someone needs it:
public static Integer getUserIdOwnerOfMsg(Message msg) {
Integer idUser = null;
try {
JSONObject jsonObject = new JSONObject();
jsonObject.put("textMsg", msg.getTextMsg());
jsonObject.put("hourMsg", msg.getHourMsg());
List list = new LinkedList();
list.addAll(Arrays.asList(jsonObject));
String jsonString = list.toString();
String urlStr = SERVER_PATH + "getUserIdOwnerOfMsgJSON.php";
URL url = new URL(urlStr);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", "your user agent");
con.setRequestProperty("Accept-Language", "sp,SP;q=0.5");
String urlParameters = "json=" + jsonString;
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream (con.getOutputStream());
byte[] buf = urlParameters.getBytes("UTF-8");
wr.write(buf, 0, buf.length);
wr.flush();
wr.close();
InputStream instream;
int status = con.getResponseCode();
if (status != HttpURLConnection.HTTP_OK)
instream = con.getErrorStream();
else
instream = con.getInputStream();
BufferedReader in = new BufferedReader(new InputStreamReader(instream, Charset.forName("UTF-8")),8192);
String inputLine;
StringBuilder response = new StringBuilder();
while((inputLine = in.readLine()) != null)
response.append(inputLine);
JSONObject object = new JSONObject(response.toString());
Boolean correct = object.getBoolean("correct");
if (correct) {
try {
String idUserText = object.getString("id");
idUser = Integer.valueOf(idUserText);
} catch (NumberFormatException e) {
e.printStackTrace();
}
}
in.close();
} catch (Exception e) {
e.printStackTrace();
}
return idUser;
}
That's all, happy coding!