java网络编程（四）java实现发送post请求

野性酷女 2022-05-14 02:00 1546阅读 0赞

post、get请求一般出现在前端调用后端接口的时候，现在如果希望java代码去调用controller接口，比如在job定时器中，达到某一条件需要返回给前端一条提示消息（如订单30分钟内未付款，已被自动取消），而前端只能调controler接口，所以这时可以用job去调controller接口，在这个controller接口里面返回信息给前端。

* @param url:请求url 
         * @param content: 请求体(参数) 
         * @return errorStr:错误信息;status:状态码，response：返回数据 
         */  
        public Map<String, Object> request(String url, String content) {  
            Map<String, Object> result = new HashMap<String, Object>();  
            String errorStr = "";  
            String status = "";  
            String response = "";  
            PrintWriter out = null;  
            BufferedReader in = null;  
            try {  
                URL realUrl = new URL(url);  
                // 打开和URL之间的连接  
                URLConnection conn = realUrl.openConnection();  
                HttpURLConnection httpUrlConnection = (HttpURLConnection) conn;  
                // 设置请求属性  
                httpUrlConnection.setRequestProperty("Content-Type", "application/json");  
                httpUrlConnection.setRequestProperty("x-adviewrtb-version", "2.1");  
                // 发送POST请求必须设置如下两行  
                httpUrlConnection.setDoOutput(true);  
                httpUrlConnection.setDoInput(true);  
                // 获取URLConnection对象对应的输出流  
                out = new PrintWriter(httpUrlConnection.getOutputStream());  
                // 发送请求参数  
                out.write(content);  
                // flush输出流的缓冲  
                out.flush();  
                httpUrlConnection.connect();  
                // 定义BufferedReader输入流来读取URL的响应  
                in = new BufferedReader(new InputStreamReader(httpUrlConnection.getInputStream()));  
                String line;  
                while ((line = in.readLine()) != null) {  
                    response += line;  
                }  
                status = new Integer(httpUrlConnection.getResponseCode()).toString();  
            } catch (Exception e) {  
                System.out.println("发送 POST 请求出现异常！" + e);  
                errorStr = e.getMessage();  
            }  
            // 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 (Exception ex) {  
                    ex.printStackTrace();  
                }  
            }  
             
            result.put("errorStr", errorStr);  
            result.put("response", response);  
            result.put("status", status);  
            return result;  
      
        }