Try to change your code like this:
conn.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded; charset: UTF-8");
byte[] output = data.getBytes("UTF-8");
conn.setFixedLengthStreamingMode(output.length);
os = conn.getOutputStream();
os.write(output);
os.flush();
os.close();
DisplayResponseHeaders(conn);
if (conn.getResponseCode() == 200) { // or other 2xx code like 204
s = readStream(conn.getInputStream());
Log.d("body", s);
}
else {
// handle error conditions like 404, 400, 500, ...
// now it may be necessary to read the error stream
InputStream errorStream = conn.getErrorStream();
// ...
}
AFAIK you should always close all streams you opened. I'm not sure whether conn.disconnect()
is doing that for you.
If you want to code your HTTP(S) requests more conveniently, you can have a look at DavidWebb where you have a list of libraries helping you to avoid using cumbersome HttpURLConnection.