package com.tutego.insel.solutions.thread;

import java.io.*;

public class DateiBeobachter implements Runnable
{
  private File file;
  private Runnable run;
	
  public DateiBeobachter( String s, Runnable r )
  {
    this( new File(s), r );
  }
	
  public DateiBeobachter( File f, Runnable r )
  {
    file = f;
    run  = r;
  }
  
  public void run()
  {
    long last = file.lastModified();
    
    while( true )
    {
      long newlastmod = file.lastModified();
      
      if ( last < newlastmod )
      {
        last = newlastmod;
        run.run();
      }
      
      try
      {
        Thread.sleep( 500 );
      }
      catch ( Exception e ) { }
    }
  }
  
  public static void main( String args[] )
  {
    String filename = "c:/yes.txt";

    DateiBeobachter db = new DateiBeobachter( filename, new InformMe() );

    Thread t = new Thread( db );
    t.start();
  }
}

class InformMe implements Runnable
{
  public void run()
  {
    System.out.println( "Geändert. Toll gemacht!" );
  }
}