Bean Dumper

package com.bruceeckel;
 
// : c14:BeanDumper.java
// Introspecting a Bean.
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
 
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.BeanInfo;
import java.beans.EventSetDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.MethodDescriptor;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
 
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
 
public class BeanDumper extends JFrame {
    private JTextField query = new JTextField(20);
 
    private JTextArea results = new JTextArea();
 
    public void print(String s) {
	results.append(s + "\n");
    }
 
    public void dump(Class bean) {
	results.setText("");
	BeanInfo bi = null;
	try {
	    bi = Introspector.getBeanInfo(bean, Object.class);
	} catch (IntrospectionException e) {
	    print("Couldn't introspect " + bean.getName());
	    return;
	}
	PropertyDescriptor[] properties = bi.getPropertyDescriptors();
	for (int i = 0; i < properties.length; i++) {
	    Class p = properties[i].getPropertyType();
	    if (p == null)
		continue;
	    print("Property type:\n  " + p.getName() + "Property name:\n  " + properties[i].getName());
	    Method readMethod = properties[i].getReadMethod();
	    if (readMethod != null)
		print("Read method:\n  " + readMethod);
	    Method writeMethod = properties[i].getWriteMethod();
	    if (writeMethod != null)
		print("Write method:\n  " + writeMethod);
	    print("====================");
	}
	print("Public methods:");
	MethodDescriptor[] methods = bi.getMethodDescriptors();
	for (int i = 0; i < methods.length; i++)
	    print(methods[i].getMethod().toString());
	print("======================");
	print("Event support:");
	EventSetDescriptor[] events = bi.getEventSetDescriptors();
	for (int i = 0; i < events.length; i++) {
	    print("Listener type:\n  " + events[i].getListenerType().getName());
	    Method[] lm = events[i].getListenerMethods();
	    for (int j = 0; j < lm.length; j++)
		print("Listener method:\n  " + lm[j].getName());
	    MethodDescriptor[] lmd = events[i].getListenerMethodDescriptors();
	    for (int j = 0; j < lmd.length; j++)
		print("Method descriptor:\n  " + lmd[j].getMethod());
	    Method addListener = events[i].getAddListenerMethod();
	    print("Add Listener Method:\n  " + addListener);
	    Method removeListener = events[i].getRemoveListenerMethod();
	    print("Remove Listener Method:\n  " + removeListener);
	    print("====================");
	}
    }
 
    class Dumper implements ActionListener {
	public void actionPerformed(ActionEvent e) {
	    String name = query.getText();
	    Class c = null;
	    try {
		c = Class.forName(name);
	    } catch (ClassNotFoundException ex) {
		results.setText("Couldn't find " + name);
		return;
	    }
	    dump(c);
	}
    }
 
    public BeanDumper() {
	Container cp = getContentPane();
	JPanel p = new JPanel();
	p.setLayout(new FlowLayout());
	p.add(new JLabel("Qualified bean name:"));
	p.add(query);
	cp.add(BorderLayout.NORTH, p);
	cp.add(new JScrollPane(results));
	Dumper dmpr = new Dumper();
	query.addActionListener(dmpr);
	query.setText("frogbean.Frog");
	// Force evaluation
	dmpr.actionPerformed(new ActionEvent(dmpr, 0, ""));
    }
 
    public static void main(String[] args) {
	run(new BeanDumper(), 600, 500);
 
    }
 
    public static void run(JFrame frame, int width, int height) {
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	frame.setSize(width, height);
	frame.setVisible(true);
    }
 
}