使用ScheduledExecutorService接口实现Web轮询项目

web.xml：

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"><web-app><display-name>Schedule Application</display-name> <context-param><param-name>webAppRootKey</param-name><param-value>schedule.root</param-value></context-param>  <!-- 生产环境设为0 --><context-param><param-name>log4jRefreshInterval</param-name><param-value>0</param-value></context-param><context-param><param-name>log4jConfigLocation</param-name><param-value>/WEB-INF/classes/log4j.properties</param-value></context-param><context-param><param-name>contextConfigLocation</param-name><param-value>/WEB-INF/classes/*Context.xml</param-value><!-- classpath:applicationContext.xml,classpath*:*Context.xml --></context-param><servlet><servlet-name>SecheduleServlet</servlet-name><servlet-class>com.wonders.schedule.servlet.ScheduleServlet</servlet-class><load-on-startup>1</load-on-startup></servlet><filter><filter-name>struts2</filter-name><description>Struts2 Filter</description><filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class></filter><filter><filter-name>struts2-cleanup</filter-name><description>Struts2 CleanUp Filter</description><filter-class>org.apache.struts2.dispatcher.ActionContextCleanUp</filter-class></filter><filter><filter-name>EncodingFilter</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class><init-param><param-name>encoding</param-name><param-value>utf-8</param-value></init-param></filter><filter-mapping><filter-name>struts2-cleanup</filter-name><url-pattern>/*</url-pattern></filter-mapping><filter-mapping><filter-name>struts2</filter-name><url-pattern>/*</url-pattern></filter-mapping><filter-mapping><filter-name>EncodingFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping> <listener><listener-class>org.springframework.web.util.Log4jConfigListener</listener-class></listener><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener><welcome-file-list><welcome-file>login.jsp</welcome-file></welcome-file-list><!-- session失效时间 分钟<session-config>      <session-timeout>-1</session-timeout>  </session-config>  --></web-app>

servlet：

/**   *    * 项目名称：schedule   * 类名称：ScheduleServlet   * 类描述：   * 创建人：zhoushun   * 创建时间：2012-11-27 下午06:45:17   * 修改人：zhoushun   * 修改时间：2012-11-27 下午06:45:17   * 修改备注：   * @version    *    */package com.wonders.schedule.servlet;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.wonders.schedule.common.util.SimpleLogger;import com.wonders.schedule.main.ScheduleMain;/**  * @ClassName: ScheduleServlet  * @Description: TODO(计划任务)  * @author zhoushun * @date 2012-11-27 下午06:45:17  *   */public class ScheduleServlet extends HttpServlet {SimpleLogger log = new SimpleLogger(this.getClass());/** *  */private static final long serialVersionUID = -1600327747212116607L;@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {// TODO Auto-generated method stubsuper.doPost(req, resp);}@Overridepublic void destroy() {// TODO Auto-generated method stubsuper.destroy();}/** * @Title: init * @Description: TODO(这里用一句话描述这个方法的作用) * @param @throws ServletException    设定文件 * @throws */@Overridepublic void init() throws ServletException {// TODO Auto-generated method stubsuper.init();log.debug("计划任务启动");ScheduleMain.start();}}

main：

/** *  */package com.wonders.schedule.main;import java.util.List;import java.util.concurrent.Executors;import java.util.concurrent.ScheduledExecutorService;import java.util.concurrent.TimeUnit;import org.apache.log4j.Logger;import com.wonders.schedule.common.util.SimpleLogger;import com.wonders.schedule.manage.ScheduleTask;import com.wonders.schedule.model.bo.TScheduleConfig;import com.wonders.schedule.service.ScheduleService;import com.wonders.schedule.util.TimeUtil;/** * @ClassName: ScheduleMain * @Description: TODO(这里用一句话描述这个类的作用) * @author zhoushun * @date 2012-12-4 上午10:26:48 *  */public class ScheduleMain {static Logger log = SimpleLogger.getLogger(ScheduleMain.class);private ScheduleMain() {}/** * 定时执行 */private static ScheduledExecutorService scheduler = null;/** * @Title: addTask * @Description: TODO(增加计划任务) * @param @param config 设定文件 * @return void 返回类型 * @throws */public static void addTask(TScheduleConfig t) {long delay = TimeUtil.getDelay(t.getTime(), t.getInterval());long period = TimeUtil.getIntervalSec(t.getInterval());log.debug(t.getName() + " 模块正在启动" + " 延迟为：" + delay + " 周期为：" + period);ScheduleTask task = new ScheduleTask(t);//若之前执行失败，强制执行一次if(!TimeUtil.isExec(t.getLastTime(), t.getTime(), t.getInterval())){scheduler.schedule(task,0,TimeUnit.SECONDS);}scheduler.scheduleAtFixedRate(task, delay, period,TimeUnit.SECONDS);}/** * @Title: start * @Description: TODO(计划任务启动) * @param 设定文件 * @return void 返回类型 * @throws */public static void start() {if (scheduler == null) {scheduler = Executors.newScheduledThreadPool(20);synchronized (scheduler) {List<TScheduleConfig> list = ScheduleService.getSvcConfig();for (TScheduleConfig t : list) {addTask(t);}}} else {log.warn("定时器正在运行!");}}/** * @Title: stop * @Description: TODO(停止) * @param 设定文件 * @return void 返回类型 * @throws */public static void stop() {synchronized (scheduler) {if (scheduler != null && !scheduler.isShutdown()) {scheduler.shutdown();scheduler = null;log.debug("关闭定时器!");}}}/** * @Title: restart * @Description: TODO(重启) * @param 设定文件 * @return void 返回类型 * @throws */public static void restart() {stop();start();}/** * @Title: trigger * @Description: TODO(手动触发 用于交互) * @param 设定文件 * @return void 返回类型 * @throws */public static void trigger() {}}

task：需要继承runnable接口

/** *  */package com.wonders.schedule.manage;import java.util.concurrent.Semaphore;import com.wonders.schedule.model.bo.TScheduleConfig;/** * @ClassName: ScheduleTask * @Description: TODO(这里用一句话描述这个类的作用) * @author zhoushun * @date 2012-12-4 下午02:52:19 *  */public class ScheduleTask implements Runnable {private TScheduleConfig t;/** * 同步信号量 */private final Semaphore semaphore = new Semaphore(1);public ScheduleTask(TScheduleConfig t) {this.t = t;}/** * @Title: run * @Description: TODO(这里用一句话描述这个方法的作用) * @param 设定文件 * @throws */@Overridepublic void run() {try {semaphore.acquire();ScheduleManager.operate(t);} catch (InterruptedException e) {e.printStackTrace();} finally {semaphore.release();}}}