java项目启动时执行指定方法 java怎样实现项目启动时执行指定方法

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

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();
 } 
}