Interface Observer

@Deprecated(since="9")
public interface Observer
Deprecated.
This interface has been deprecated. See the Observable class for further information.

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

Since:
1.0
See Also:
Observable

Methods

Modifier and Type Method Description
void update​(Observable o, Object arg)

Deprecated.

This method is called whenever the observed object is changed.

Methods

update

void update(Observable o,
            Object arg)
Deprecated.

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.

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https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/Observer.html