JavaTM 2 Platform
Standard Ed. 5.0

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
 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.

JavaTM 2 Platform
Standard Ed. 5.0

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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