public static String sendPost(String url, String param) {      PrintWriter out = null;      BufferedReader in = null;      String result = "";      try {        URL realUrl = new URL(url);        // 打開和URL之間的連接        URLConnection conn = realUrl.openConnection();        // 設置通用的請求屬性        conn.setRequestProperty("accept", "*/*");        conn.setRequestProperty("connection", "Keep-Alive");        conn.setRequestProperty("user-agent",            "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");        conn.setConnectTimeout(4000);        conn.setReadTimeout(4000);        // 發送POST請求必須設置如下兩行        conn.setDoOutput(true);        conn.setDoInput(true);        // 獲取URLConnection對象對應的輸出流        out = new PrintWriter(conn.getOutputStream());        // 發送請求參數        out.print(param);        // flush輸出流的緩沖        out.flush();        // 定義BufferedReader輸入流來讀取URL的響應        in = new BufferedReader(            new InputStreamReader(conn.getInputStream()));        String line;        while ((line = in.readLine()) != null) {          result += line;        }      } catch (Exception e) {        System.out.println("發送 POST 請求出現異常！");        //e.printStackTrace();      }      //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(IOException ex){          //ex.printStackTrace();        }      }      return result;    }