Main.java Source code

Introduction

Here is the source code for Main.java

Source

// A vetoable property change event is fired when a constrained property is changed. 
// A listener can veto the change by throwing PropertyVetoException and preventing the change.

import java.beans.PropertyChangeEvent;
import java.beans.PropertyVetoException;
import java.beans.VetoableChangeListener;
import java.beans.VetoableChangeSupport;

public class Main {
    public static void main(String[] argv) throws Exception {
        MyBean bean = new MyBean();
        bean.addVetoableChangeListener(new MyVetoableChangeListener());
    }
}

class MyVetoableChangeListener implements VetoableChangeListener {
    public void vetoableChange(PropertyChangeEvent evt) throws PropertyVetoException {
        Object oldValue = evt.getOldValue();

        Object newValue = evt.getNewValue();

        boolean veto = false;
        if (veto) {
            throw new PropertyVetoException("the reason for the veto", evt);
        }
    }
}

class MyBean {
    VetoableChangeSupport vceListeners = new VetoableChangeSupport(this);

    int myProperty;

    public int getMyProperty() {
        return myProperty;
    }

    public void setMyProperty(int newValue) throws PropertyVetoException {
        try {
            vceListeners.fireVetoableChange("myProperty", new Integer(myProperty), new Integer(newValue));
            myProperty = newValue;
        } catch (PropertyVetoException e) {
            throw e;
        }
    }

    public synchronized void addVetoableChangeListener(VetoableChangeListener listener) {
        vceListeners.addVetoableChangeListener(listener);
    }

    public synchronized void removeVetoableChangeListener(VetoableChangeListener listener) {
        vceListeners.removeVetoableChangeListener(listener);
    }

}