java.util.Observer Maven / Gradle / Ivy
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This work corresponds to the API signatures of JSR 219: Foundation
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*/
package java.util;
/**
* A class can implement the Observer interface when it
* wants to be informed of changes in observable objects.
*
* @author Chris Warth
* @version 1.16, 02/02/00
* @see java.util.Observable
* @since JDK1.0
*/
public interface Observer
{
/**
* 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.
*
* @param o the observable object.
* @param arg an argument passed to the notifyObservers
* method.
*/
public void update(Observable o, Object arg);
}