Here you can find the source of mkdir(File directory)
public static File mkdir(File directory) throws IOException
//package com.java2s; /*/*from w w w. ja va2s .c o m*/ * ao-lang - Minimal Java library with no external dependencies shared by many other projects. * Copyright (C) 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 AO Industries, Inc. * support@aoindustries.com * 7262 Bull Pen Cir * Mobile, AL 36695 * * This file is part of ao-lang. * * ao-lang 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 3 of the License, or * (at your option) any later version. * * ao-lang 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. * * You should have received a copy of the GNU Lesser General Public License * along with ao-lang. If not, see <http://www.gnu.org/licenses/>. */ import java.io.File; import java.io.IOException; public class Main { /** * Makes a directory. The directory must not already exist. * * @return The directory itself. * * @exception IOException if mkdir fails. */ public static File mkdir(File directory) throws IOException { if (!directory.mkdir()) throw new IOException("Unable to create directory: " + directory.getPath()); return directory; } }