Here you can find the source of mkdir(final File dir)
public static void mkdir(final File dir) throws IOException
//package com.java2s; /*//w ww .j a v a 2 s .c o m * Sonatype Nexus (TM) Open Source Version * Copyright (c) 2008-present Sonatype, Inc. * All rights reserved. Includes the third-party code listed at http://links.sonatype.com/products/nexus/oss/attributions. * * This program and the accompanying materials are made available under the terms of the Eclipse Public License Version 1.0, * which accompanies this distribution and is available at http://www.eclipse.org/legal/epl-v10.html. * * Sonatype Nexus (TM) Professional Version is available from Sonatype, Inc. "Sonatype" and "Sonatype Nexus" are trademarks * of Sonatype, Inc. Apache Maven is a trademark of the Apache Software Foundation. M2eclipse is a trademark of the * Eclipse Foundation. All other trademarks are the property of their respective owners. */ import java.io.File; import java.io.IOException; import java.nio.file.FileAlreadyExistsException; import java.nio.file.Files; import java.nio.file.Path; public class Main { /** * Creates a directory. Fails only if directory creation fails, otherwise cleanly returns. If cleanly returns, * it is guaranteed that passed in path is created (with all parents as needed) successfully. Unlike Java7 * {@link Files#createDirectories(Path, FileAttribute[])} method, this method does support paths having last * path element a symlink too. In this case, it's verified that symlink points to a directory and is readable. */ public static void mkdir(final Path dir) throws IOException { try { Files.createDirectories(dir); } catch (FileAlreadyExistsException e) { // this happens when last element of path exists, but is a symlink. // A simple test with Files.isDirectory should be able to detect this // case as by default, it follows symlinks. if (!Files.isDirectory(dir)) { throw e; } } } /** * @since 2.8 */ public static void mkdir(final File dir) throws IOException { mkdir(dir.toPath()); } }