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
Methods
| Modifier and Type | Method and Description |
|---|---|
void |
update(Observable o,
Object arg) This method is called whenever the observed object is changed. |
Methods
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 thenotifyObserversmethod.
© 1993, 2020, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/javase/8/docs/api/java/util/Observer.html