站想要让搜索引擎搜到，必须设置好keywords，description，title，做好SEO优化，同时sitemap.xml也是不可缺少的
通过Google，得到一些帮助，把自己做的整理一下：
第一、对文件进行查找：
 
    public class FileDemo {
      File myDir;
      File[] contents;
      List fileList;
      Iterator currentFileIt;
      File currentFile;
      String path;
     
      /**
       * 无参的构造函数
       * */
      public FileDemo() {
        path = new String("");
        fileList = new ArrayList();
      }
     
      /**
       * 有参的构造函数
       * */
      public FileDemo(String path) {
        this.path = path;
        fileList = new ArrayList();
      }
     
      /**
       * 设置要查看的文件路径
       */
      public void setPath(String path) {
        this.path = path;
      }
     
      /***************************************************************************
       * 返回当前目录的路径
       */
      public String getDirectory() {
        return myDir.getPath();
      }
     
      public void refreshList() {
        if (this.path.equals(""))
          path = "c:\\";
        myDir = new File(path);
     
        fileList.clear();
        contents = myDir.listFiles();
        // 重新装入路径下文件
        for (int i = 0; i < contents.length; i++) {
          fileList.add(contents[i]);
        }
        currentFileIt = fileList.iterator();
      }
     
      /**
       * 指到下一个条目
       */
      public boolean nextFile() {
        while (currentFileIt.hasNext()) {
          currentFile = (File) currentFileIt.next();
          
          return true;
        }
        return false;
      }
     
      /**
       * 返回当前指向的文件对象的文件名称
       */
      public String getFileName() {
        return currentFile.getName();
      }
     
      /**
       * 返回当前指向的文件对象的文件尺寸
       */
      public String getFileSize() {
        return convertFileSize(currentFile.length());
      }
     
      /**
       * 转换文件尺寸为指定格式。
       */
      private String convertFileSize(long size) {
        int divisor = 1;
        String unit = "bytes";
        if (size >= 1024 * 1024) {
          divisor = 1024 * 1024;
          unit = "MB";
        } else if (size >= 1024) {
          divisor = 1024;
          unit = "KB";
        }
        if (divisor == 1)
          return size / divisor + " " + unit;
        String aftercomma = "" + 100 * (size % divisor) / divisor;
        if (aftercomma.length() == 1)
          aftercomma = "0" + aftercomma;
        return size / divisor + "." + aftercomma + " " + unit;
      }
     
      /**
       * 返回文件的最后修改日期
       */
      public String getFileTimeStamp() {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String dateString = sdf.format(new Date(currentFile.lastModified()));
     
        return dateString;
      }
     
      /**
       * 返回文件是不是一个目录
       */
      public boolean isDirectory() {
        return currentFile.isDirectory();
      }
     
    }
 
第二、创建一个任务类,继承TimerTask
    public class XMLParese extends TimerTask{
      
      private ServletContext context;
      
      public XMLParese(ServletContext context){
        this.context=context;
      }
      
      @Override
      public void run() {
        // TODO Auto-generated method stub
        createSiteMap();
        
      }
      public void createSiteMap() {
     
        String priority = "0.75";// 级 别
        String changefreq = "daily";// "weekly";//频 率
        String xmlpath = "e:/sitemap.xml";// sitemap名称以及位置    
        String homeurl = "http://www.jsedu114.com"; // 栏目首页
        String []directory={"promotion","news","brand","goods","services","shop","winelive"};
        FileDemo fp = new FileDemo();
        try {
          Document document = DocumentHelper.createDocument();
          Element urlsetElement = document.addElement("urlset");
          urlsetElement.addAttribute("xmlns ",
              "http://www.sitemaps.org/schemas/sitemap/0.9"); // "xmlns
                                      // "必须要有空格,否则会报错
          urlsetElement.addAttribute("xmlns",
              "http://www.sitemaps.org/schemas/sitemap/0.9");
     
          urlsetElement.addAttribute("xmlns:xsi",
              "http://www.w3.org/2001/XMLSchema-instance");
     
          urlsetElement.addAttribute("xsi:schemaLocation",
              "http://www.sitemaps.org/schemas/sitemap/0.9 " +
     
              "http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd");
          
          //创建url根元素
          Element urlElement ;
          //为url根元素创建loc网页地址，lastmod更新时间，changefreq更改频率和priority级别
          Element locElement ;
          Element lastmodElement;
          Element changefreqElement;
          Element priorityElement;
          fp.setPath("D:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\webapps\\ROOT\\");
          fp.refreshList();
          while (fp.nextFile()) {
            if (!fp.isDirectory()) {
              homeurl="http://www.jsedu114.com/";
              String f=fp.getFileName();
              String fname=f.substring(f.lastIndexOf("."));
              if((fname.equals(".html")||fname.equals(".htm")) && !f.equals("login.html")){
                urlElement = urlsetElement.addElement("url");
                locElement = urlElement.addElement("loc");
                lastmodElement = urlElement.addElement("lastmod");
                changefreqElement = urlElement.addElement("changefreq");
                priorityElement = urlElement.addElement("priority");
                
                //导航赋值
                homeurl = homeurl + fp.getFileName();
                locElement.setText(homeurl);
                lastmodElement.setText(fp.getFileTimeStamp());// 这里时间是你更新时间，这里暂时统一
                changefreqElement.setText(changefreq);
                priorityElement.setText(priority);
              }
            }
          }
          
                //各个目录下的文件
          for(int i=0;i<directory.length;i++){
            fp.setPath("D:\\Program Files\\Apache Software Foundation\\Tomcat 6.0\\webapps\\ROOT\\"+directory[i]+"\\");
            fp.refreshList();
            while (fp.nextFile()) {
              homeurl="http://www.jsedu114.com/"+directory[i]+"/";              
              urlElement = urlsetElement.addElement("url");
              locElement = urlElement.addElement("loc");
              lastmodElement = urlElement.addElement("lastmod");
              changefreqElement = urlElement.addElement("changefreq");
              priorityElement = urlElement.addElement("priority");              
              
              homeurl = homeurl + fp.getFileName();
              locElement.setText(homeurl);
              lastmodElement.setText(fp.getFileTimeStamp());// 这里时间是你更新时间，这里暂时统一
              changefreqElement.setText(changefreq);
              priorityElement.setText(priority);
            }
          }
     
          XMLWriter writer = new XMLWriter(new FileOutputStream(new File(
              xmlpath)));
          writer.write(document);
          writer.close();
          document = null;
          // 格式化
          formatXMLFile(xmlpath, "UTF-8");
        } catch (Exception ex) {
          ex.printStackTrace();
     
        }
     
      }
     
      /**
       * 格式化XML文档,并解决中文问题
       * @param xmlpath：xml文件路径
       * @param charSet:格式化的字符集
       * @return
       */
      public static boolean formatXMLFile(String xmlpath, String charSet) {
     
        boolean returnValue = false;
        try {
     
          SAXReader saxReader = new SAXReader();
          Document document = saxReader.read(new File(xmlpath));
          XMLWriter output = null;
          OutputFormat format = OutputFormat.createPrettyPrint();
          format.setEncoding(charSet);
          output = new XMLWriter(new FileWriter(new File(xmlpath)), format);
          output.write(document);
          output.close();
          document = null;
          saxReader = null;
          returnValue = true;
        } catch (Exception ex) {
          ex.printStackTrace();
        }
        return returnValue;
      }
     
    }
 
 第三、创建一个任务监听类，实现ServletContextListener 接口
 
    public class TimerListener implements ServletContextListener {
      // 设置启动时间为23点;
      private static final int hours = 23;
      private static final int minutes = 0;
      private static final int seconds = 0;
      private Timer timer = null;
     
      public void contextDestroyed(ServletContextEvent event) {
        timer.cancel();
        event.getServletContext().log("定时器销毁");
      }
     
      public void contextInitialized(ServletContextEvent event) {
            timer=new Timer(true);
            event.getServletContext().log("定时器已启动");
            Calendar calendar = Calendar.getInstance();
            calendar.set(Calendar.HOUR_OF_DAY, hours);
            calendar.set(Calendar.MINUTE, minutes);
            calendar.set(Calendar.SECOND, seconds);
            
            //SiteMap生成
            //间隔时间1天生成一次
            timer.schedule(new XMLParese(event.getServletContext()),calendar.getTime(),
                1*24*60*60*1000);
      }
    }
 
第四、在web中添加一个监听器
       web.xml里的配置
 
<!-- 定时器 -->
<listener>
  <listener-class>timer.TimerListener</listener-class>
</listener>