public class HttpRequest {
    /**
     * 向指定URL傳送GET方法的請求
     * 
     * @param url
     *            傳送請求的URL
     * @param param
     *            請求引數，請求引數應該是 name1=value1&name2=value2 的形式。
     * @return URL 所代表遠端資源的響應結果
     */
    public static String sendGet(String url, String param) {
        String result = ""
 
;
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            // 開啟和URL之間的連線
            URLConnection connection = realUrl.openConnection();
            // 設定通用的請求屬性
            connection.setRequestProperty("accept"
 
, "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立實際的連線
            connection.connect();
            // 獲取所有響應頭欄位
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍歷所有的響應頭欄位
 

            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }
            // 定義 BufferedReader輸入流來讀取URL的響應
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("傳送GET請求出現異常！" + e);
            e.printStackTrace();
        }
        // 使用finally塊來關閉輸入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }

    /**
     * 向指定 URL 傳送POST方法的請求
     * 
     * @param url
     *            傳送請求的 URL
     * @param param
     *            請求引數，請求引數應該是 name1=value1&name2=value2 的形式。
     * @return 所代表遠端資源的響應結果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 開啟和URL之間的連線
            URLConnection conn = realUrl.openConnection();
            // 設定通用的請求屬性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 傳送POST請求必須設定如下兩行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 獲取URLConnection物件對應的輸出流
            out = new PrintWriter(conn.getOutputStream());
            // 傳送請求引數
            out.print(param);
            // flush輸出流的緩衝
            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("傳送 POST 請求出現異常！"+e);
            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;
    }    
}

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimerTask;

public class MyTask extends TimerTask{
    private int i= 0;
    @Override
    public void run() {
        Calendar c= Calendar.getInstance();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
//      System.out.println("當前時間："+sdf.format(c.getTime()));
        if(c.get(Calendar.DAY_OF_MONTH)==1){
            i++;
            System.out.println("當前時間："+sdf.format(c.getTime()));
            System.out.println("第"+i+"次執行任務開始");
            String s=HttpRequest.sendGet("http://localhost:8080/taizhoushopping/test1", "key=555&v=456");
            System.out.println("應答資訊："+s);
            System.out.println("第"+i+"次執行任務結束");
        }

    }

}

public class Run {
    public static void main(String[] args) {
//        //傳送 GET 請求
//        String s=HttpRequest.sendGet("http://localhost:8080/taizhoushopping/test1", "key=555&v=456");
//        System.out.println(s);

        //傳送 POST 請求
//        String sr=HttpRequest.sendPost("http://localhost:8080/taizhoushopping/test1", "key=123&v=456");
//        System.out.println(sr);

        Run r = new Run();
        r.runtask();
    }




    public void runtask(){

        Calendar c1 = Calendar.getInstance();
        c1.setTime(new Date());

        Timer t = new Timer();


        Calendar c2 = Calendar.getInstance();
        c2.set(Calendar.DAY_OF_MONTH, c1.get(Calendar.DAY_OF_MONTH)+1);
        c2.set(Calendar.HOUR_OF_DAY, 0);
        c2.set(Calendar.SECOND, 0);
        c2.set(Calendar.MINUTE, 0);

        long diffs = c2.getTimeInMillis()-c1.getTimeInMillis();


        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        MyTask task = new MyTask();
        t.scheduleAtFixedRate(task, diffs, 24*60*60*1000);

    }
}

任務執行：從啟動計時，第二天凌晨第一次執行任務，之後每隔24小時執行一次，若當天時間為每月1號，則傳送http請求