public class Log4jThread extends Thread {
   private File file;
   private long lastModified;
   private final long millis = 10 * 1000L;
   
   public Log4jThread(String path) {
      setName(Log4jThread.class.getSimpleName());
      file = new File(path);
      lastModified = file.lastModified();
      PropertyConfigurator.configure(path);
   }

   public void run() {
      while(true) {
         try {
            sleep(millis);

            if(file.lastModified() != lastModified) {
               //PropertyConfigurator.configure(file.getCanonicalPath());
               DOMConfigurator.configure(file.getCanonicalPath());
               lastModified = file.lastModified();
               System.out.println("Info: The log4j.properties is reload!");
            }
         }
         catch(InterruptedException e) {
            System.err.println("Error: The log4j thread is interrupted!");
         }
         catch(IOException e) {
            System.err.println("Error: Cann't find '" + file.getName() + "'!");
         }
      }
   }
}