Recursion: Directory Crawl Example with Java

Directory.java

import java.io.*;

public class Directory {
	private static void crawl(File f, int indent) { 
		
		// Always print the name of the File object, with appropriate indentation
		for(int i=0; i<4*indent; i++) { 
			System.out.print(" ");
		}
		System.out.println(f.getName());
		
		// Recursive case: is directory
		if(f.isDirectory()) {
			File[] files = f.listFiles();
			for(File tempfile : files) {
				crawl(tempfile, indent+1);
			}
		}
		// Base case: file (return nothing)
	}

	public static void crawl(File f) {
		// This public method hides the "indentation" detail from the user
		crawl(f,0);
	}

	public static void main(String[] args) { 
		crawl(new File("/temp"));
	}
}