Here you can find the source of mkdir(String folder)
public static void mkdir(String folder)
//package com.java2s; //License from project: Apache License import java.io.*; public class Main { public static void mkdir(String folder) { File file = new File(folder); if (!file.exists()) { file.mkdir();/*from w w w.ja v a 2s . c om*/ System.out.println(file); System.out.println(file.getAbsoluteFile()); System.out.println(file.getAbsolutePath()); } } }