json接口远程调用

String content=""; 
          try {
            URL url = new URL(urlStr);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url
                    .openConnection(); //获取连接 
            httpURLConnection.setRequestMethod("GET"); //设置请求方法为POST, 也可以为GET 
            httpURLConnection.setDoOutput(true);
            InputStream is = httpURLConnection.getInputStream();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            StringBuilder sb = new StringBuilder();
            while (br.read() != -1) {
                sb.append(br.readLine());
            }
            content = new String(sb);
            content = new String(content.getBytes("GB2312"), "ISO-8859-1");
            br.close();
        } catch (Exception e) {
            throw new Exception("付款接口调用失败！");
        }

// 以上为调用的远程接口，数据传输格式为JSON


JSONObject jsonObject = JSONObject.fromObject("{" + content);
  String expenseCode = jsonObject.getString("expense_code");