java.util

Interface Observer


  • public interface Observer
    A class can implement the Observer interface when it wants to be informed of changes in observable objects.
    Since:
    JDK1.0
    See Also:
    Observable

    • Method Summary

      Modifier and Type Method and Description
      void update(Observable o, Object arg)
      This method is called whenever the observed object is changed.

    • Method Detail

      • update

        void update(Observable o,
            Object arg)
        This method is called whenever the observed object is changed. An application calls an Observable object's notifyObservers method to have all the object's observers notified of the change.
        Parameters:
        o - the observable object.
        arg - an argument passed to the notifyObservers method.