Here you can find the source of makedirs(String fileName)
public static void makedirs(String fileName) throws IOException
//package com.java2s; /**//from w ww. j av a2 s . c om * Copyright 2008 - 2012 * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. * * @project loon * @author cping * @email?javachenpeng@yahoo.com * @version 0.3.3 */ import java.io.File; import java.io.IOException; public class Main { public static void makedirs(String fileName) throws IOException { makedirs(new File(fileName)); } public static void makedirs(File file) throws IOException { checkFile(file); File parentFile = file.getParentFile(); if (parentFile != null) { if (!parentFile.exists() && !parentFile.mkdirs()) { throw new IOException("Creating directories " + parentFile.getPath() + " failed."); } } } private static void checkFile(File file) throws IOException { boolean exists = file.exists(); if (exists && !file.isFile()) { throw new IOException("File " + file.getPath() + " is actually not a file."); } } }