/*
 * 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.
 */

/**
 * ShowAllInterfaces.java
 *
 * Java Examples In A Nutshell Copyright (c) 2000 David Flanagan
 * Exercise 8-2:
 * Modify the program you wrote in Exercise 8-1 so that it prints out all inter-
 * faces implemented by a specified class or by any of its superclasses. Check
 * for the case of classes that implement interfaces that extend other interfaces.
 * For example, if a class implements java.awt.LayoutManager2, the LayoutManager2
 * interface and LayoutManager, its superinterface, should be listed.
 *
 * @author Matthew Feldt <developer@feldt.com>
 * @version 1.0, 04/16/2001 19:10
 */

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

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

	ShowAllInterfaces(Class c) {
		loadAllInterfaces(c);
	}

	private void loadAllInterfaces(Class c) {
		Class superclass = c.getSuperclass();
		Class[] classInterfaces = c.getInterfaces();

		// class contains interfaces if interfaces.length != 0
		if (classInterfaces.length != 0) {
			// iterate through all interfaces to see if any implement other
			// interfaces not yet recorded
			for (int i = 0; i < classInterfaces.length; i++) {
				// add interface name if not yet recorded
				if (! interfaces.contains(classInterfaces[i].getName())) {
					interfaces.add(classInterfaces[i].getName());
				}
			}
		}

		if (superclass != null) { // root class if superclass == null
			loadAllInterfaces(superclass); // recurse
		}
	}

	public String[] getAllInterfaces() {
		return (String[])interfaces.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]);
			ShowAllInterfaces sai = new ShowAllInterfaces(c);
			String[] interfaces = sai.getAllInterfaces();

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