We create a directory by calling mkdir() method of the File object. This method returns true if and only if the directory was successfully created. If false was returned, no directory is created. This could be caused, for example that the directory was already exists.

package org.kodejava.io;

import java.io.File;

public class CreateDirectoryExample {
    public static void main(String[] args) {
        File file = new File("tmpdir");

        if (file.mkdir()) {
            System.out.println("Directory = " + file.getAbsolutePath());
        } else {
            System.out.println("No directory was created");
        }
    }
}

Here is the result of the program:

Directory = F:\Wayan\Kodejava\kodejava-example\tmpdir