Add the following things to the java code

import java.io.File;

import java.util.Scanner;

public class RecursiveFileDirectoryDisplay {

public static void main(String[] args) {

Scanner scnr = new Scanner(System.in);//for input

System.out.print("Please Enter Root Directory: ");//prompt user

String rootDirectory = scnr.nextLine();//set rootDirectory to user input

System.out.println("List of all Directory & files under " + rootDirectory);

System.out.println("------------------------------------");

displayDirectoryContents(rootDirectory);// call method to recurse and print

}

public static void displayDirectoryContents(String rootDirectory) {

File root = new File(rootDirectory);

if (root.exists()) { //if root directory exists

File[] list = root.listFiles(); //create array of all files in root directory

if (list != null) {//if list is not null

for (File f : list) {

if (f.isDirectory()) {//if it is a directory

System.out.println("Directory: " + f.getAbsoluteFile());// print

displayDirectoryContents(f.getAbsolutePath());//send back in

} else {//else it is a file

System.out.println("File : " + f.getAbsoluteFile());// print the file name

}

}

}

else {//

System.out.println("Input root directory is not exists!");// print error message

}

}

}

}

However, you need to extend it as follows: When the user inputs wrong information (i.e., not a readable directory), a custom exception is thrown internally . The custom exception results in the user being prompted again. Do not print directories, only files. * Create an ArrayList and add the directories to the ArrayList. Print the ArrayList when your program is finished. So: Ask for user input, validate/throw internal error, print files/add dirs, print dirs, done