Here you can find the source of mkdirs(File dir)
public static void mkdirs(File dir) throws IOException
//package com.java2s; /**//from w w w . j a v a 2s .c o m * JLibs: Common Utilities for Java * Copyright (C) 2009 Santhosh Kumar T <santhosh.tekuri@gmail.com> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. */ import java.io.*; public class Main { /** * create specified directory if doesn't exist. * if any parent diretories doesn't exist they will * be created implicitly */ public static void mkdirs(File dir) throws IOException { if (!dir.exists() && !dir.mkdirs()) throw new IOException("couldn't create directory: " + dir); } }