Apache Commons IO File Monitoring Example

Here is another example from the archives of the mythical archana on File monitoring using Apache Commons I/O for file monitoring. I remember working on this to see if we could come up with a solution since we could not upgrade the application to Java SE 7. So this proof of concept was to try out a couple of different file monitoring options.

This example uses a FileAlterationListener to monitor file changes. It is simple to implement.

The code for the project can be found here: file-monitor

	package com.bluelotussoftware.commons.io;
	import java.io.File;
	import java.util.Date;
	import org.apache.commons.io.monitor.FileAlterationListener;
	import org.apache.commons.io.monitor.FileAlterationObserver;
	/**
	*
	* @author John Yeary
	* @version 1.0
	*/
	public class FileAlterationListenerImpl implements FileAlterationListener {
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onStart(final FileAlterationObserver observer) {
	System.out.println("The WindowsFileListener has started on " + observer.getDirectory().getAbsolutePath());
	}
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onDirectoryCreate(final File directory) {
	System.out.println(directory.getAbsolutePath() + " was created.");
	}
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onDirectoryChange(final File directory) {
	System.out.println(directory.getAbsolutePath() + " wa modified");
	}
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onDirectoryDelete(final File directory) {
	System.out.println(directory.getAbsolutePath() + " was deleted.");
	}
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onFileCreate(final File file) {
	System.out.println(file.getAbsoluteFile() + " was created.");
	System.out.println("----------> length: " + file.length());
	System.out.println("----------> last modified: " + new Date(file.lastModified()));
	System.out.println("----------> readable: " + file.canRead());
	System.out.println("----------> writable: " + file.canWrite());
	System.out.println("----------> executable: " + file.canExecute());
	}
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onFileChange(final File file) {
	System.out.println(file.getAbsoluteFile() + " was modified.");
	System.out.println("----------> length: " + file.length());
	System.out.println("----------> last modified: " + new Date(file.lastModified()));
	System.out.println("----------> readable: " + file.canRead());
	System.out.println("----------> writable: " + file.canWrite());
	System.out.println("----------> executable: " + file.canExecute());
	}
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onFileDelete(final File file) {
	System.out.println(file.getAbsoluteFile() + " was deleted.");
	}
	/**
	* {@inheritDoc}
	*/
	@Override
	public void onStop(final FileAlterationObserver observer) {
	System.out.println("The WindowsFileListener has stopped on " + observer.getDirectory().getAbsolutePath());
	}
	}

view raw FileAlterationListenerImpl.java hosted with ❤ by GitHub

	package com.bluelotussoftware.commons.io;
	import java.io.File;
	import org.apache.commons.io.monitor.FileAlterationMonitor;
	import org.apache.commons.io.monitor.FileAlterationObserver;
	/**
	*
	* @author John Yeary
	* @version 1.0
	*/
	public class FileMonitor {
	public static void main(String[] args) throws Exception {
	// Change this to match the environment you want to watch.
	final File directory = new File("/Users/jyeary/Desktop");
	FileAlterationObserver fao = new FileAlterationObserver(directory);
	fao.addListener(new FileAlterationListenerImpl());
	final FileAlterationMonitor monitor = new FileAlterationMonitor();
	monitor.addObserver(fao);
	System.out.println("Starting monitor. CTRL+C to stop.");
	monitor.start();
	Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
	@Override
	public void run() {
	try {
	System.out.println("Stopping monitor.");
	monitor.stop();
	} catch (Exception ignored) {
	}
	}
	}));
	}
	}

view raw FileMonitor.java hosted with ❤ by GitHub