myobservable.java

来自「java绘图 java awt 经典绘图的例子,对于初学awt模块的人非常有帮助」· Java 代码 · 共 57 行

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package observer;

import java.util.Observable;
import java.util.Vector;

/**
 *
 * @author zhaolin
 */
public class MyObservable{
    private Vector<MyObserver> observers;
    private boolean changed;
    
    public MyObservable(){
        observers = new Vector<MyObserver>();
    }
    
    public void addObserver(MyObserver o){
        observers.add(o);
    }
    
    public void setChanged(){
        this.changed = true;
    }
    
    public void  notifyAllMyObservers(){
        if(!changed)
            return;
        for(MyObserver o:observers){
            o.update(this, null);
        }
    }
    
    public static void main(String[] args) {
        MyObserver o = new MyObserver(){

            public void update(MyObservable o, Object obj) {
                System.out.println("somthing happened to "+o);
            }
            
        };
        
        Somthing s = new Somthing();
        s.addObserver(o);
        s.setI(10);
        
        
    }

}