post、get請求一般出現在前端呼叫後端介面的時候，現在如果希望java程式碼去呼叫controller介面，比如在job定時器中，達到某一條件需要返回給前端一條提示訊息（如訂單30分鐘內未付款，已被自動取消），而前端只能調controler介面，所以這時可以用job去調controller介面，在這個controller接口裡面返回資訊給前端。

 * @param url:請求url 
     * @param content: 請求體(引數) 
     * @return errorStr:錯誤資訊;status:狀態碼，response：返回資料 
     */  
    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);  
            // 開啟和URL之間的連線  
            URLConnection conn = realUrl.openConnection();  
            HttpURLConnection httpUrlConnection = (HttpURLConnection) conn;  
            // 設定請求屬性  
            httpUrlConnection.setRequestProperty("Content-Type", "application/json");  
            httpUrlConnection.setRequestProperty("x-adviewrtb-version", "2.1");  
            // 傳送POST請求必須設定如下兩行  
            httpUrlConnection.setDoOutput(true);  
            httpUrlConnection.setDoInput(true);  
            // 獲取URLConnection物件對應的輸出流  
            out = new PrintWriter(httpUrlConnection.getOutputStream());  
            // 傳送請求引數  
            out.write(content);  
            // flush輸出流的緩衝  
            out.flush();  
            httpUrlConnection.connect();  
            // 定義BufferedReader輸入流來讀取URL的響應  
            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("傳送 POST 請求出現異常！" + e);  
            errorStr = e.getMessage();  
        }  
        // 使用finally塊來關閉輸出流、輸入流  
        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;  
  
    }