JAVA任务调度实现方法一
背景：目前因工作需要，要实现WEB项目设计动态加载XML文件的功能。这些XML文件的数据是动态从数据库中获取到的，其中数据库中数据每一小时更新一次。因此需要每一小时动态生成XML文件。这就要用到JAVA中得任务调度功能。
总的来说，分为两部分：1.项目启动时通过servlet调度任务；2.通过JAVA?QUARTS?每一小时进行一次任务调度。
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项目架构：SSH(struts2+spring+hibernate)
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言归正传，进入正题，开始讨论这两种方法的实现.
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一 servlet 任务调度
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1. web.xml 中servlet的配置
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<servlet><servlet-name>CreateXmlForCharts</servlet-name><servlet-class>cn.gov.cma.servlet.CreateXmlForCharts</servlet-class> <load-on-startup>3</load-on-startup></servlet><servlet-mapping><servlet-name>CreateXmlForCharts</servlet-name><url-pattern>/XmlTools/CreateXmlForCharts</url-pattern></servlet-mapping>
?2. servlet 的任务调度 方法
protected void service(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {String xpwd = request.getParameter("xpwd");if (xpwd == null || !xpwd.equals("administrator"))return;System.out.println("-------------CreateXmlForCharts------anytime ---------"+ new Date());// 获取SPRING中的<bean>节点的globalQueue队列对象。WebApplicationContext webapplicationcontext = WebApplicationContextUtils.getRequiredWebApplicationContext(this.getServletContext());ICreateXmlForChartsService createxmlforchartsservice = (CreateXmlForChartsServiceImpl) webapplicationcontext.getBean("createxmlforchartsservice");long starta = System.currentTimeMillis();List<Integer> list = createxmlforchartsservice.findAllStationID();// stationid// 的list// 之后按此list进行生成xml的动作.long startb = System.currentTimeMillis();System.out.println(startb - starta+ "========findAllStationID======time");System.out.println(list.size());String[] hours = DateUtils.getTimeString(24);// 指定时间段字符串数组.// for(String h:hours) System.out.println(h);System.out.println("_+_+_+_+_+_+_+_");String[] sbtime = DateUtils.getTimeBeginAndEndString(24);// for(String h:sbtime) System.out.println(h);long startc = System.currentTimeMillis();Map<String, EleAwstPublicvo> map = createxmlforchartsservice.findAllEleAwstPublic(sbtime[1], sbtime[0]);// 存放着指定时间段内,所有的stationid对应的实况信息.long startd = System.currentTimeMillis();System.out.println(startd - startc+ "========findAllEleAwstPublic======time");System.out.println(map.size());int listsize = list.size();Integer stationid;List<EleAwstPublicvo> listEleAwstPublicvo;PrintWriter out;//String filepath = "/usr/product/apache-tomcat-6.0.32/webapps/productdb_flex/demo/";String filepath = "D:/productdb/tomcat 6/webapps/productdb_flex/demo/";File filefolder = new File(filepath);if (!filefolder.exists())filefolder.mkdirs();for (int i = 0; i < listsize; i++) {stationid = list.get(i);listEleAwstPublicvo = CreateXml.getEleAwstPublicvolistByStationID(stationid, map, hours);if (stationid == 45011) {for (EleAwstPublicvo o : listEleAwstPublicvo) {System.out.println(o.getV01000() + "|" + o.getcBjtime()+ "|" + o.getV12001() + "|" + o.getV11043() + "|"+ o.getV11041() + "|" + o.getV13003() + "|"+ o.getV13019());}}out = new PrintWriter(filepath + stationid + "temperature.xml", "gb2312");CreateXml.createTemperatureXml(stationid, listEleAwstPublicvo, out);out = new PrintWriter(filepath + stationid + "humidity.xml", "gb2312");CreateXml.createHumidityXml(stationid, listEleAwstPublicvo, out);out = new PrintWriter(// //"out\"+ 需要就自己加上文件夹名称filepath + stationid + "wind.xml", "gb2312");CreateXml.createWindXml(stationid, listEleAwstPublicvo, out);out = new PrintWriter(filepath + stationid + "precipitation.xml", "gb2312");CreateXml.createPrecipitationXml(stationid, listEleAwstPublicvo,out);}long starte = System.currentTimeMillis();System.out.println(starte - startd+ "========compare and write xml======time");}?
关键点：
WebApplicationContext webapplicationcontext = WebApplicationContextUtils
????.getRequiredWebApplicationContext(this.getServletContext());
??ICreateXmlForChartsService createxmlforchartsservice = (CreateXmlForChartsServiceImpl) webapplicationcontext
????.getBean("createxmlforchartsservice");
首先：通过SPRING提供的WebApplicationContextUtils 类方法得到WebApplicationContext的对象；
然后：通过WebApplicationContext对象得到service bean 对象；
之后就可以调用service方法，即业务方法。
很简单，是不是，（：-：）
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二 QUARTS任务调度实现
1. 首先介绍一下QUARTS, Quartz是OpenSymphony提供的任务调度库类。借助一SPRING对QUARTS的很好的支持，可以很方便的使用这套任务调度库类。
以下是SPRING中QUARTS得配置：
<?xml version="1.0" encoding="UTF-8"?><beansxmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:jee="http://www.springframework.org/schema/jee"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsdhttp://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.0.xsd"> <!-- 要调用的工作类 --> <bean id="quartzJob" ref="createxmlforchartsservice"></property> </bean> <!-- 定义调用对象和调用对象的方法 --> <bean id="jobtask" lazy-init="false" autowire="no" name="code">public void createXml() {System.out.println("-------------CreateXmlForCharts------quartzs ---------"+ new Date());long starta = System.currentTimeMillis();List<Integer> list = createxmlforchartsservice.findAllStationID();// stationid// 的list// 之后按此list进行生成xml的动作.long startb = System.currentTimeMillis();System.out.println(startb - starta+ "========findAllStationID======time");System.out.println(list.size());String[] hours = DateUtils.getTimeString(24);// 指定时间段字符串数组.// for(String h:hours) System.out.println(h);System.out.println("_+_+_+_+_+_+_+_");String[] sbtime = DateUtils.getTimeBeginAndEndString(24);// for(String h:sbtime) System.out.println(h);long startc = System.currentTimeMillis();Map<String, EleAwstPublicvo> map = createxmlforchartsservice.findAllEleAwstPublic(sbtime[1], sbtime[0]);// 存放着指定时间段内,所有的stationid对应的实况信息.long startd = System.currentTimeMillis();System.out.println(startd - startc+ "========findAllEleAwstPublic======time");System.out.println(map.size());int listsize = list.size();Integer stationid;List<EleAwstPublicvo> listEleAwstPublicvo;PrintWriter out;//String filepath = "/usr/product/apache-tomcat-6.0.32/webapps/productdb_flex/demo/";String filepath = "D:/productdb/tomcat 6/webapps/productdb_flex/demo/";File filefolder = new File(filepath);if (!filefolder.exists())filefolder.mkdirs();try {for (int i = 0; i < listsize; i++) {stationid = list.get(i);listEleAwstPublicvo = CreateXml.getEleAwstPublicvolistByStationID(stationid, map,hours);/* * if(i==500){ for(EleAwstPublicvo o:listEleAwstPublicvo ) { * System * .out.println(o.getV01000()+"|"+o.getcBjtime()+"|"+o.getV12001 * ( * )+"|"+o.getV11043()+"|"+o.getV11041()+"|"+o.getV13003()+"|"+o * .getV13019()); } } */out = new PrintWriter(filepath + stationid + "temperature.xml", "gb2312");CreateXml.createTemperatureXml(stationid, listEleAwstPublicvo,out);out = new PrintWriter(filepath + stationid + "humidity.xml", "gb2312");CreateXml.createHumidityXml(stationid, listEleAwstPublicvo, out);out = new PrintWriter(// //"out\"+ 需要就自己加上文件夹名称filepath + stationid + "wind.xml", "gb2312");CreateXml.createWindXml(stationid, listEleAwstPublicvo, out);out = new PrintWriter(filepath + stationid + "precipitation.xml", "gb2312");CreateXml.createPrecipitationXml(stationid,listEleAwstPublicvo, out);}} catch (IOException e) {e.printStackTrace();}long starte = System.currentTimeMillis();System.out.println(starte - startd+ "========compare and write xml======time");}?Over....
后续要补充一下java.util.Timer任务调度实现。
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