streamToString

private String streamToString(InputStream inputStream,String charset) {    try {        InputStreamReader inputStreamReader = new InputStreamReader(inputStream,charset);        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);        String s = null;        StringBuilder builder = new StringBuilder();        while ((s = bufferedReader.readLine()) != null){            builder.append(s);        }        bufferedReader.close();        return builder.toString();    } catch (Exception e) {        e.printStackTrace();    }    return  null;}