Java 后台请求第三方系统接口详解

//调用第三方系统接口
            PrintWriter out = null;
            BufferedReader in = null;
            JSONObject jsonObject = null;
            CloseableHttpResponse response = null;
            String result = "";
            try {
                //请求地址
                URL realUrl = new URL("http://127.0.0.1:8081/services/trad/findBy");
                // 打开和URL之间的连接
                HttpURLConnection conn = (HttpURLConnection)realUrl.openConnection();
                // 设置通用的请求属性
                conn.setRequestMethod("POST");
                // 发送POST请求必须设置下面的属性
                conn.setDoOutput(true);
                conn.setDoInput(true);
                conn.setUseCaches(false);
                //设置请求属性
                conn.setRequestProperty("Content-Type", "application/json; charset=utf-8");

                conn.connect();
                // 获取URLConnection对象对应的输出流
                out = new PrintWriter(conn.getOutputStream());
                // 发送请求参数
                out.print(encrypt);
                // flush输出流的缓冲
                out.flush();
                // 定义BufferedReader输入流来读取URL的响应
                in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));
                String line = "";
                while ((line = in.readLine()) != null) {
                    result += line;
                }

                //将返回结果转换为json
                JSONArray jsonArray = JSONArray.fromObject(result);
                
                return jsonArray;

            } catch (Exception e) {
                e.printStackTrace();
            }
            // 使用finally块来关闭输出流、输入流
            finally {
                try {
                    if (out != null) {
                        out.close();
                    }
                    if (in != null) {
                        in.close();
                    }
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }