监听器ServletContextListener小记

最新推荐文章于 2025-04-30 18:06:50 发布

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最新推荐文章于 2025-04-30 18:06:50 发布

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分类专栏： Java知识文章标签： exception string timer tomcat file class

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文章分类:Java编程
   今天奉命写一个监听器监听tomcat，在tomcat启动后隔半个小时生成一些要求的静态页面，因为没写过监听器，所以在网上看了一些资料后觉得不是很难就很兴奋地开始动手，
   用了ServletContextListener,可没想到监听是监听到了，但是搞得tomcat启动的时候一路在监听，以为是这个监听器不适合就换成了session的，以为快成功的
   时候老大又说不行（后来一想也确实不行），所以又换回ServletContextListener来继续搞，后来上网看来看去原来用这个监听器才是符合要求的，一开始那种
   只不过是因为我把定时器Timer定义在了ServletContextListener的初始化函数里面了，搞得tomcat启动时老是在监听而启动不了，后来我把定时器Timer定义在
   另外一个类里面，再在ServletContextListener的初始化函数里面调用就搞定了。还是没经验啊。

不过这里还有个问题：如何在这个初始化函数里面获得tomcat的IP和端口呢？也许很难，也许很easy,还不知道！

   Listener:
   Java代码：
public class GenPagesListener implements ServletContextListener
{
        private DoSomething ds = null;

    public void contextInitialized(ServletContextEvent sce) {

            String rootPath = new File(sce.getServletContext().getRealPath("/")).getParentFile().toString();
                if(rootPath.contains("//"))
                {
                        rootPath = rootPath.replace("//", "/")+"/ROOT";
                }
                String hostPath = AppPropertyUtil.getProperty("webUrl");


                GlobeContext.setRootPath(rootPath);
                GlobeContext.setHostPath(hostPath);

            ds = new DoSomething(1000,1800000);
    }

    public void contextDestroyed(ServletContextEvent sce) {
       ds.destoryTimer();
    }

}
==============
中间类：
public class DoSomething {

        private java.util.Timer timer;
        public DoSomething(int a,int b)
        {
                timer = new Timer();
                timer.schedule(new GenPageTask(), a,b);
        }

        public void destoryTimer(){
            timer.cancel();
            }
}

==========
要执行的任务：
public class GenPageTask extends TimerTask{

        public void run()
        {
                ApplicationContext context = GlobeContext.getApplicationContext();
                IChannelManager channelManager = (IChannelManager)context.getBean("channelManager");
                List<Channel> list = channelManager.getObjectList(Restrictions.eq("type", 1));

                for(Channel ch : list)
                {
                        Long lid = ch.getId();
                        try{
                        publishChannel(lid);
                        }
                        catch(Exception e)
                        {
                           e.printStackTrace();
                        }
                }
        }

        public void publishChannel(Long lid) throws Exception
        {

                String root = GlobeContext.getRootPath();
                String rootpath = GlobeContext.getHostPath();
                ApplicationContext context = GlobeContext.getApplicationContext();
                IChannelManager channelManager = (IChannelManager)context.getBean("channelManager");
                ChannelView chan = channelManager.getView(lid);
                String puppath = root + chan.getFullPath();
                File file = new File(puppath);
                if (!file.exists()) {
                        file.mkdirs();
                }

                int pageSize = Integer.valueOf(AppPropertyUtil
                                .getProperty("listPageSize"));
                if (chan.getPageSize() != null) {
                        pageSize = chan.getPageSize();
                }
                try {
                        List<Criterion> cris = new ArrayList<Criterion>();
                        cris.add(Restrictions.eq("channelId", chan.getId()));
                        cris.add(Restrictions.eq("struts", 1));
                        IDocumentManager documentManager = (IDocumentManager)context.getBean("documentManager");
                        int totalPage = documentManager.getPageObject(0, pageSize, cris)
                                        .getTotalPage();

                        for (int page = 1; page <= totalPage; page++) {
                                String index = "";
                                if (page == 1) {
                                        index = "index";
                                } else {
                                        index = "list_" + page + "";
                                }
                                String url = rootpath
                                                + "admin/channel/docList.htm?data.channelId="
                                                + chan.getId() + "&data.page=" + page;
                                HtmlGenUtil.writeHtml(puppath + index + ".shtml", HtmlGenUtil
                                                .getHtmlCode(url), "YES");
                        }
                } catch (Exception e) {
                        e.printStackTrace();
                }
        }
}