程序包 java.util

接口 Observer

public interface Observer

A class can implement the Observer interface when it wants to be informed of changes in observable objects.

从以下版本开始:

JDK1.0

另请参阅:

Observable

方法概要

限定符和类型	方法	说明
void	update(Observable o, Object arg)	This method is called whenever the observed object is changed.

方法详细资料

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.

参数:

o - the observable object.

arg - an argument passed to the notifyObservers method.