Program to create a new Directory using File class:

import java.io.*;
class mkdirDemo
{
	public static void main(String[] s)
	{
		File f = new File("newDir");
		f.mkdir();
		System.out.println("Directory created.");	
	}	
}

Output:
create 1 directory

Program to create multiple new Directories using File class:

In case if we would like to create multiple nested directories, A different function is to be invoked. which is: mkdirs()

import java.io.*;
class mkdirsDemo
{
	public static void main(String[] s)
	{
		File f = new File("a/b/newDir/testDir/c");
		f.mkdirs();
		System.out.println("Directories created.");	
	}	
}

Output:
create multiple directories
create multiple directories