private String streamToString(InputStream inputStream, String charset) {

    try {
        //轉換流,將位元組流轉字串,並轉換編碼
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, charset);
        //字元緩衝流
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
        //字串緩衝區
StringBuilder stringBuilder = new 
 
StringBuilder();
        //
String len = null;
        //按行讀
while((len=bufferedReader.readLine())!=null){
            //追加到字串緩衝區存放
stringBuilder.append(len);
        }
        //將字串返回
return stringBuilder.toString();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}