Java tutorial
//package com.java2s; import java.awt.Component; import java.awt.Container; public class Main { static public void printAllComponents(Component root, int level) { if (root == null) return; printSpaceBeforeContent(level, root.getClass().getSimpleName()); if (root instanceof Container) { Component[] components = ((Container) root).getComponents(); if (components == null || components.length == 0) { return; } for (Component comp : components) { printAllComponents(comp, level + 1); } } } private static void printSpaceBeforeContent(int count, String content) { for (int i = 0; i < count; i++) { System.out.print(" "); } System.out.println(content); } }