Java basics
notifyObserver
The java.util.Observable.notifyObservers() method notify all of its observers if the object has changed. This method later calls the clearChanged method to indicate that this object has no longer changed. This method is equivalent to notifyObservers(null).
Declaration
Syntax:public void notifyObservers()
Example:import java.util.Observable;
import java.util.Observer;
class ObservedObject extends Observable {
private String watchedValue;
public ObservedObject(String value) {
watchedValue = value;
}
public void setValue(String value) {
// if value has changed notify observers
if(!watchedValue.equals(value)) {
System.out.println("Value changed to new value: "+value);
watchedValue = value;
// mark as value changed
setChanged();
// trigger notification
notifyObservers();
}
}
}
public class ObservableDemo implements Observer {
public String name;
public ObservableDemo(String name) {
this.name = name;
}
public static void main(String[] args) {
// create watched and watcher objects
ObservedObject watched = new ObservedObject("Original Value");
// watcher object listens to object change
ObservableDemo watcher = new ObservableDemo("Watcher");
// add observer to the watched object
watched.addObserver(watcher);
// trigger value change
watched.setValue("New Value");
}
public void update(Observable obj, Object arg) {
System.out.println("Update called");
}
}
Content
License.
All information of this service is derived from the free sources and is provided solely in the form of quotations.
This service provides information and interfaces solely for the familiarization (not ownership) and under the "as is" condition.
Copyright 2016 © ELTASK.COM. All rights reserved.
Site is optimized for mobile devices.
Downloads: 154 / 159136718. Delta: 0.00350 с