import java.io.File; class DirectoryTree { public static void main(String args[]) { File file = new File(args[0]); if (!file.exists()) { System.out.println(args[0] + " does not exist."); return; } tree(args[0]); } public static void tree(String filename) { File file = new File(filename); if (!file.isDirectory()) { System.out.println(filename); return; } String files[] = file.list(); for (int i = 0; i < files.length; i++) { tree(filename + File.separator + files[i]); } } }