There is an excellent tutorial at The Java Tutorial called
Using the Timer and TimerTask Classes.

It explains how to use a timer to schedule tasks or to perform tasks repeatedly. With the Timer and TimerTask classes you don’t have to create your own threads, it’s all done for you. Thank you Joshua Bloch for writing these classes.

On a side note, Joshua Bloch is one of the premier Java engineers. Recently he left Sun for Google. Gosh, that must have hurt Sun.

JavaWorld has a great article on finding a class’s runtime origin called Back to your Class roots. Below is the highly useful getClassLocation method from the article.

/**
 * Given a Class object, attempts to find its .class location.
 * Use for testing/debugging only.
 * 
 * @return URL that points to the class definition; null if not found
 */
public static URL getClassLocation (final Class cls) {
  if (cls == null) throw new IllegalArgumentException ("null input");
  
  URL result = null;
  final String clsAsResource = cls.getName ().replace ('.', '/').concat (".class");
  
  final ProtectionDomain pd = cls.getProtectionDomain ();
  // java.lang.Class contract does not specify if 'pd' can ever be
  // null; it is not the case for Sun's implementations, but guard
  // against null just in case:
  if (pd != null) {
    final CodeSource cs = pd.getCodeSource ();
    // 'cs' can be null depending on the classloader behavior:
    if (cs != null) result = cs.getLocation ();
    
    if (result != null) {
      // Convert a code source location into a full class file location
      // for some common cases:
      if ("file".equals (result.getProtocol ())) {
        try {
          if (result.toExternalForm ().endsWith (".jar") ||
            result.toExternalForm ().endsWith (".zip")) 
            result = new URL ("jar:".concat (result.toExternalForm ())
              .concat("!/").concat (clsAsResource));
          else if (new File (result.getFile ()).isDirectory ())
            result = new URL (result, clsAsResource);
        }
        catch (MalformedURLException ignore) {}
      }
    }
  }
  
  if (result == null) {
    // Try to find 'cls' definition as a resource; this is not
    // documented to be legal, but Sun's implementations seem to allow
    // this:
    final ClassLoader clsLoader = cls.getClassLoader ();
    
    result = clsLoader != null ?
      clsLoader.getResource (clsAsResource) :
      ClassLoader.getSystemResource (clsAsResource);
  }
  
  return result;
}