/*
 * Copyright (c) 2001 Matthew Feldt. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided the copyright notice above is
 * retained.
 *
 * THIS SOFTWARE IS PROVIDED ''AS IS'' AND WITHOUT ANY EXPRESSED OR
 * IMPLIED WARRANTIES.
 */

/**
 * ShowSuperClasses.java
 *
 * Java Examples In A Nutshell Copyright (c) 2000 David Flanagan
 * Exercise 8-1:
 * Write a program that takes the name of a Java class as a command-line argument
 * and uses the Class class to print out all the superclasses of that class.
 * For example, if invoked with the argument "java.applet.Applet", the program
 * prints the following: java.lang.Object java.awt.Component java.awt.Container
 * java.awt.Panel.
 *
 * @author Matthew Feldt <developer@feldt.com>
 * @version 1.0, 04/14/2001 19:07
 */

package com.feldt.examples.reflect;
import java.util.*;

public class ShowSuperClasses {
	static final String USAGE = "Usage: java ShowSuperClasses <classname>";
	private static ArrayList superclasses = new ArrayList();

	ShowSuperClasses(Class c) {
		loadSuperClasses(c);
	}

	/** populate the superclasses array */
	private void loadSuperClasses(Class c) {
		Class superclass = c.getSuperclass(); // get superclass if any

		if (superclass != null) { // root class if superclass == null
			superclasses.add(superclass.getName()); // add class name
			loadSuperClasses(superclass); // recurse
		}
	}

	/** return a String listing the super classes of the specified class */
	public String[] getSuperClasses() {
		return (String[])superclasses.toArray(new String[0]);
	}

	public static void main(String[] args) throws ClassNotFoundException {
		try {
			if (args.length != 1)
				throw new IllegalArgumentException(
					"Incorrect number of command line arguments.");

			Class c = Class.forName(args[0]);
			ShowSuperClasses ssc = new ShowSuperClasses(c);
			String[] superclasses = ssc.getSuperClasses();

			System.out.println();
			System.out.println("Super Classes:");
			for (int i = 0; i < superclasses.length; i++) {
				System.out.println(superclasses[i]);
			}
		} catch (Exception e) {
			System.err.println(e.getMessage());
			System.exit(-1);
		}
	}
}