Java/Development Class/SimpleBeanInfo

A Bean information class.

 
import java.beans.PropertyDescriptor;
import java.beans.SimpleBeanInfo;
public class ColorsBeanInfo extends SimpleBeanInfo {
  public PropertyDescriptor[] getPropertyDescriptors() {
    try {
      PropertyDescriptor rectangular = new PropertyDescriptor("rectangular", Colors.class);
      PropertyDescriptor pd[] = { rectangular };
      return pd;
    } catch (Exception e) {
    }
    return null;
  }
}

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.Serializable;
import javax.swing.JLabel;
public class Colors extends JLabel implements Serializable {
  transient private Color color; // not persistent
  private boolean rectangular; // is persistent
  public Colors() {
    addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent me) {
        change();
      }
    });
    rectangular = false;
    setSize(200, 100);
    change();
  }
  public boolean getRectangular() {
    return rectangular;
  }
  public void setRectangular(boolean flag) {
    this.rectangular = flag;
    repaint();
  }
  public void change() {
    color = randomColor();
    repaint();
  }
  private Color randomColor() {
    int r = (int) (255 * Math.random());
    int g = (int) (255 * Math.random());
    int b = (int) (255 * Math.random());
    return new Color(r, g, b);
  }
  public void paint(Graphics g) {
    Dimension d = getSize();
    int h = d.height;
    int w = d.width;
    g.setColor(color);
    if (rectangular) {
      g.fillRect(0, 0, w - 1, h - 1);
    } else {
      g.fillOval(0, 0, w - 1, h - 1);
    }
  }
}

Show properties and events.

 
import java.beans.BeanInfo;
import java.beans.EventSetDescriptor;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
public class IntrospectorDemo {
  public static void main(String args[]) {
    try {
      Class c = Class.forName("Colors");
      BeanInfo beanInfo = Introspector.getBeanInfo(c);
      System.out.println("Properties:");
      PropertyDescriptor propertyDescriptor[] = beanInfo.getPropertyDescriptors();
      for (int i = 0; i < propertyDescriptor.length; i++) {
        System.out.println("\t" + propertyDescriptor[i].getName());
      }
      System.out.println("Events:");
      EventSetDescriptor eventSetDescriptor[] = beanInfo.getEventSetDescriptors();
      for (int i = 0; i < eventSetDescriptor.length; i++) {
        System.out.println("\t" + eventSetDescriptor[i].getName());
      }
    } catch (Exception e) {
      System.out.println("Exception caught. " + e);
    }
  }
}