PHR.java

import java.io.FileReader;
import java.io.IOException;
import java.io.BufferedReader;
import java.util.*;
import java.io.*;

public class PHR {
	public static void main(String[] args) throws IOException {

		// monitor a single file
    TimerTask task = new FileWatcher( new File("phrlist.txt") ) {
      protected void onChange( File file ) throws IOException  {
        // here we code the action on a change
        System.out.println( "File "+ file.getName() +" have change !" );
        updated();
      }
    };

    Timer timer = new Timer();
    // repeat the check every second
    timer.schedule( task , new Date(), 1000 );
	}

	private static void updated() throws IOException {
		FileReader in = null;
		FileWriter out = null;

		BufferedReader input = null;
		PrintWriter output = null;
		try {			
			in = new FileReader("phrlist.txt");
			input = new BufferedReader(in);
			
			String s; 
			while ((s = input.readLine()) != null) {
				//output.println(s);
				System.out.println(">> " + s);
			}
		} finally {
			if (input != null) {
				input.close();
			}
			if (in != null) {
				in.close();
			}			
		}
	}

	public abstract static class FileWatcher extends TimerTask {
	  private long timeStamp;
	  private File file;

	  public FileWatcher( File file ) {
	    this.file = file;
	    this.timeStamp = file.lastModified();
	  }

	  public final void run() {
	    long timeStamp = file.lastModified();

	    if( this.timeStamp != timeStamp ) {
	      this.timeStamp = timeStamp;
	      try {
	      	onChange(file);
	    	} catch(Exception e) {

	    	}
	    }
	  }

	  protected abstract void onChange( File file ) throws IOException ;
  }
}