Observer Example (1/4)
public interface FileSystemObserver {
public final static int FILE_ADDED = 1;
public final static int FILE_REMOVED = 2;
public void notify(int application, int event);
class FileSystemNotifier {
private Vector myObservers = new Vector();
public void addObserver(FileSystemObserver observer) {
myObservers.addElement(observer);
public void removeObserver(FileSystemObserver observer) {
myObservers.removeElement(observer);
public void notify(int application, int event) {
for (Enumeration e = myObservers.elements(); e.hasMoreElements();) {
((FileSystemObserver)e.nextElement()).notify(application, event);