java.beans.PropertyChangeListener

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;

public class DemoBeans {  
  
    private String demoName;  
    private String Version;    
    PropertyChangeSupport listeners = new PropertyChangeSupport(this);  
  
    public DemoBeans() {  
        demoName = "initValue";  
        Version="v1000";
    }  
  
  
    public String getDemoName() {  
        return demoName;  
    }  
      
  
    public void setDemoName(String demoName) {  
        String oldValue = this.demoName;  
        this.demoName = demoName;  
        //发布监听事件  
        firePropertyChange("demoName", oldValue, demoName);  
          
    }  
      
    public void setDemoVersion(String demoVersion) {  
        String oldVersion = this.Version;  
        this.Version = demoVersion;  
        //发布监听事件  
        firePropertyChange("demoVersion", oldVersion, demoVersion);  
          
    }  
    public void addPropertyChangeListener(PropertyChangeListener listener) {  
        listeners.addPropertyChangeListener(listener);  
    }  
      
    public void removePropertyChangeListener(PropertyChangeListener listener){  
        listeners.addPropertyChangeListener(listener);  
    }  
      
  
    /** 
     * 触发属性改变的事件 
     */  
    protected void firePropertyChange(String prop, Object oldValue, Object newValue) {  
        listeners.firePropertyChange(prop, oldValue, newValue);  
    }  
    public static void main(String[] args) {  
        DemoBeans beans = new DemoBeans();  
        
        beans.addPropertyChangeListener(
                new PropertyChangeListener(){  
            public void propertyChange(PropertyChangeEvent evt) {  
                 if(evt.getPropertyName().equals("demoVersion")){
                     System.out.println("version_OldValue:"+evt.getOldValue());  
                     System.out.println("version_NewValue:"+evt.getNewValue());  
                     System.out.println("version_tPropertyName:"+evt.getPropertyName());
                 }
                 else
                 {
                     System.out.println("name_OldValue:"+evt.getOldValue());  
                     System.out.println("name_NewValue:"+evt.getNewValue());  
                     System.out.println("name_tPropertyName:"+evt.getPropertyName());
                 }
                  
            }});  

        
        beans.setDemoName("test");  
        beans.setDemoVersion("v2000");
      
    }   
}