開發一個簡單的web應用定時任務

１,先開發一下定時器

public class JobSqlTimer extends Timer { private static JobSqlTimer jpt = new JobSqlTimer(); public static void start() { Date date = new Date(); date.setHours(0); date.setMinutes(10); date.setSeconds(0); jpt.scheduleAtFixedRate(new JobSqlTimerTask(), date, 30 * 24 * 60 * 60 * 1000); System.out.println("New JobPlanTimer already started...."); } public static void stop() { } public static void main(String[] args) { start(); } } 

２,再寫一下定時任務

public class JobSqlTimerTask extends TimerTask { private static Logger logger = Logger.getLogger(JobSqlTimerTask.class); public void run() { logger.debug("清理超時掃描表任務開始......"); SqlTaskRun r = new SqlTaskRun(); r.clearDB(); logger.debug("清理超時掃描表任務結束"); } } 

３,寫一個自己要執行的任務，以便定時調用

public class SqlTaskRun { private static Logger logger = Logger.getLogger(SqlTaskRun.class); public void clearDB() { Connection con = null; Statement stmt = null; String sql1 = "delete tbl_nsp_schedule s where s.workitemid in(" + "select w.workitemindex from wf_tbl_workitem_nsp w where w.workitemstate=1)"; String sql2 = "delete tbl_nsp_schedule s where s.processid in(" + "select d.draftid from tbl_process_draft d where d.endtime is not null)"; try { con = getConnection(); stmt = con.createStatement(); stmt.execute(sql1); stmt.execute(sql2); } catch (SQLException ex) { logger.error(ex); throw new RuntimeException(ex); } finally { closeConnection(con); } } public static Connection getConnection() { try { return DBHelper.getConnection(); } catch (Exception e) { logger.error(e); throw new RuntimeException(e); } } public static void closeConnection(Connection con) { try { if (con != null) { con.close(); } } catch (Exception ex) { } } } 

４,編寫一下servlet的啓動類

public class JobSqlTimerServelt extends HttpServlet { public void init() throws ServletException { System.out.println("initial Sql timer ..."); JobSqlTimer.start(); System.out.println("Sql Timer started ..."); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { JobSqlTimer.start(); } public void destroy() { JobSqlTimer.stop(); } } 

５,在web.xml文件中進行配置啓動

<servlet> <servlet-name>JobSqlTimerServelt</servlet-name> <servlet-class>cn.com.xinli.common.task.JobSqlTimerServelt</servlet-class> <load-on-startup>1</load-on-startup> </servlet> 

６,然後啓動服務後，以後這個就任務就會按時運行了。