Java_监听器监听文件夹变动

package demo4;

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;

public class Demo4 {
 public static void main(String[] args){
  try {
   WatchService service =FileSystems.getDefault().newWatchService();
   Path path=Paths.get("E:/demo");
   //注册监听器
   path.register(service, StandardWatchEventKinds.ENTRY_CREATE,StandardWatchEventKinds.ENTRY_DELETE,StandardWatchEventKinds.ENTRY_MODIFY);
   WatchKey watchkey = null;
   //获取到一个watchkey
   do{
    try {
     watchkey=service.take();
    } catch (InterruptedException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
    for(WatchEvent<?>event:watchkey.pollEvents()){
     //如果时间列表不为空，打印事件内容
     WatchEvent.Kind<?> kind=event.kind();
     Path eventPath=(Path)event.context();
     if(kind.toString().equals("ENTRY_MODIFY")){
      System.out.println("<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>");
     }
     System.out.println(eventPath+":"+kind+":"+eventPath);
     

    }
   
   System.out.println("目录内容发生改变");

  }while(watchkey.reset());
   
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

}