java项目启动时执行指定方法

想到的就是监听步骤如下：

1.配置web.xml

 <listener>
    <listener-class>com.listener.InitListener</listener-class>
</listener> 

2.编写InitListener类

 package com.listener;

 import java.io.File;

 import javax.servlet.ServletContextEvent;
 import javax.servlet.ServletContextListener;

 import com.seegot.util.PropertyUtil;

 public class InitListener implements ServletContextListener {

     @Override
     public void contextDestroyed(ServletContextEvent arg0) {
         // TODO Auto-generated method stub

     }

     @Override
     public void contextInitialized(ServletContextEvent arg0) {
         // TODO Auto-generated method stub
         System.out.println("================>[ServletContextListener]自动加载启动开始.");
         String resourceFilesPath = PropertyUtil.getProperty("tempZipPath");
         clearFiles(resourceFilesPath);
     }
     // 删除文件和目录
     private static boolean clearFiles(String workspaceRootPath) {
         File file = new File(workspaceRootPath);
         if (file.exists()) {
             deleteFile(file);
         }
         // resources 文件夹被删除后需新建
         if (!file.exists() && workspaceRootPath.endsWith("resources")) {
             return file.mkdir();
         } else if (!file.exists()) {
             return true;
         }
             return false;
         }

     private static boolean deleteFile(File file) {
         if (file.isDirectory()) {
             File[] files = file.listFiles();
             for (int i = 0; i < files.length; i++) {
                 deleteFile(files[i]);
             }
         }
             return file.delete();
     }
 }