java USES WatchService to monitor the folder example

Through WatchService API provided by java7 to achieve the monitoring of folders

package service;

import config.Config;
import java.io.IOException;
import java.nio.file.*;
import java.util.List;
import java.util.concurrent.TimeUnit;

public class WatchDirService {
  private WatchService watchService;
  private boolean notDone = true;

  public WatchDirService(String dirPath){
    init(dirPath);
  }

  private void init(String dirPath) {
    Path path = Paths.get(dirPath);
    try {
      watchService = FileSystems.getDefault().newWatchService(); // create watchService
      path.register(watchService, 
      StandardWatchEventKinds.ENTRY_CREATE,
      StandardWatchEventKinds.ENTRY_MODIFY,
      StandardWatchEventKinds.ENTRY_DELETE); // Register the events that need to be monitored ,ENTRY_CREATE  File creation ,ENTRY_MODIFY  File modification ,ENTRY_MODIFY  File deletion 
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  public void start(){
    System.out.print("watch...");
    while (notDone){
      try {
        WatchKey watchKey = watchService.poll(Config.POLL_TIME_OUT, TimeUnit.SECONDS); // This will be in a wait state , Wait to detect a change in the file under the folder , return WatchKey object 
        if(watchKey != null){
          List<WatchEvent<?>> events = watchKey.pollEvents(); // Gets all of the events 
          for (WatchEvent event : events){
            WatchEvent.Kind<?> kind = event.kind(); 
            if (kind == StandardWatchEventKinds.OVERFLOW){
              // The current disk is not available 
              continue;
            }
            WatchEvent<Path> ev = event;
            Path path = ev.context();
            if(kind == StandardWatchEventKinds.ENTRY_CREATE){
              System.out.println("create " + path.getFileName());
            }else if(kind == StandardWatchEventKinds.ENTRY_MODIFY){
              System.out.println("modify " + path.getFileName());
            }else if(kind == StandardWatchEventKinds.ENTRY_DELETE){
              System.out.println("delete " + path.getFileName());
            }
          }
          if(!watchKey.reset()){ 
            // The process has been closed 
            System.out.println("exit watch server");
            break;
          }
        }
      } catch (InterruptedException e) {
        e.printStackTrace();
        return;
      }
    }
  }
}

That's all it takes to monitor 1 folder.

Full code address: WatchServerDemo_jb51.rar