java 实现监控某目录文件变化

commons-io-2.3.jar 中，有实现文件监控的类，在org.apache.commons.io.monitor包下，

主要包括 observer ，listener，monitor 含义你懂得滴，典型观察者模式，直接上代码：

listener:

public class ZJPFileListener implements FileAlterationListener{

	
	ZJPFileMonitor monitor = null;
	@Override
	public void onStart(FileAlterationObserver observer) {
		//System.out.println("onStart");
	}
	@Override
	public void onDirectoryCreate(File directory) {
		System.out.println("onDirectoryCreate:" +  directory.getName());
	}

	@Override
	public void onDirectoryChange(File directory) {
		System.out.println("onDirectoryChange:" + directory.getName());
	}

	@Override
	public void onDirectoryDelete(File directory) {
		System.out.println("onDirectoryDelete:" + directory.getName());
	}

	@Override
	public void onFileCreate(File file) {
		System.out.println("onFileCreate:" + file.getName());
	}

	@Override
	public void onFileChange(File file) {
		System.out.println("onFileCreate : " + file.getName());
	}

	@Override
	public void onFileDelete(File file) {
		System.out.println("onFileDelete :" + file.getName());
	}

	@Override
	public void onStop(FileAlterationObserver observer) {
		//System.out.println("onStop");
	}

}

monitor

public class ZJPFileMonitor {
	
	FileAlterationMonitor monitor = null;
	public ZJPFileMonitor(long interval) throws Exception {
		monitor = new FileAlterationMonitor(interval);
	}

	public void monitor(String path, FileAlterationListener listener) {
		FileAlterationObserver observer = new FileAlterationObserver(new File(path));
		monitor.addObserver(observer);
		observer.addListener(listener);
	}
	public void stop() throws Exception{
		monitor.stop();
	}
	public void start() throws Exception {
		monitor.start();
	}
	public static void main(String[] args) throws Exception {
		ZJPFileMonitor m = new ZJPFileMonitor(5000);
		m.monitor("E:\\filepath",new ZJPFileListener());
		m.start();
	}

启动后，每5秒扫描指定路径下文件的变化，很方便