How do i make a scanner so that I'm always able to input commands

Question

I'm making a movie store program and it is working very well when i input the first command but it doesn't let me input anymore commands.

I think it is something to do with the String ChooseGenre=scan.next() but if i remove it my switch statement won't work since it doesn't take scanner variables.

I want it so that i can input a command then be able to input another command. for example: i input "Action" and it gives me a list of action movies but then input "horror" and the output would be the list of horror movies.

Here is my code

import java.util.Scanner;
import java.util.concurrent.TimeUnit;
import java.util.ArrayList;

public class oiug {

static Scanner scan = new Scanner(System.in);

public static void main(String[] args) throws InterruptedException{






    // Start of the program
            ArrayList<String> Genre = new ArrayList<String>();
            Genre.add("Action");
            Genre.add("Horror");

            System.out.println("Welcome to the movie store Please type the genre of movie you would like to"
                    + " browse");                  
            Genre.forEach(System.out::println); 



    // ArrayList for the action movies
    ArrayList<String> Action = new ArrayList<String>();
    Action.add("Die Hard");
    Action.add("Top Gun");
    Action.add("Whitehouse Down");
    Action.add("The Gentlemen");
    Action.add("Mission impossible");
    Action.add("John Wick");
    Action.add("Atomic Blonde");
    Action.add("Inception");
    Action.add("The Matrix");
    Action.add("Speed");

    // ArrayList for the Horror movies
    ArrayList<String> Horror = new ArrayList<String>();
    Horror.add("Us");
    Horror.add("It Chapter 2");
    Horror.add("Get Out");
    Horror.add("The Interior");
    Horror.add("It follows");
    Horror.add("The Ring");
    Horror.add("The Shinning");
    Horror.add("Scream");
    Horror.add("Alien");
    Horror.add("Nightmare on Elm Street");

    ArrayList<String> Documentary = new ArrayList<String>();
    Documentary.add("Free Solo");
    Documentary.add("13th");
    Documentary.add("Fyre");
    Documentary.add("Honeyland");
    Documentary.add("Strong Island");
    Documentary.add("Abducted in plain sight");
    Documentary.add("Man on Wire");
    Documentary.add("How to Survive a Plague");


     String ChooseGenre=scan.next(); 

     System.out.println("Loading."); 
     TimeUnit.SECONDS.sleep(1);
     System.out.println("Loading.."); 
     TimeUnit.SECONDS.sleep(1);
     System.out.println("Loading..."); 
     TimeUnit.SECONDS.sleep(1);

     // If the input doesn't match one of the options a "please try again messege appears"
      switch(ChooseGenre) {
         case "Horror" :
            System.out.println("you chose: Horror!"); 
            Horror.forEach(System.out::println);
            break;
         case "Action" :
             System.out.println("you chose: Action!");
             Action.forEach(System.out::println);
            break;
         case "Documentary" :
             System.out.println("you chose: Documentary!");
             Documentary.forEach(System.out::println);
         default :
            System.out.println("Please enter a Movie genre");
      }

 } 



  }

I'm not exactly skilled at programming but ill take any help i can get

You may want to start at https://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html to learn about loops. — Dawood ibn Kareem, May 10 '20 at 19:31
Does this answer your question? [Scanner is skipping nextLine() after using next() or nextFoo()?](https://stackoverflow.com/questions/13102045/scanner-is-skipping-nextline-after-using-next-or-nextfoo) — Arvind Kumar Avinash, May 10 '20 at 20:01

score 1 · Accepted Answer · answered May 10 '20 at 19:56

You can use a while loop for this.


Boolean isProgramRunning = true;
String chooseGenre;

while (isProgramRunning) {
    chooseGenre = scan.next();

    switch(chooseGenre) {
         case "Horror" :
            System.out.println("you chose: Horror!"); 
            Horror.forEach(System.out::println);
            break;
         case "Action" :
             System.out.println("you chose: Action!");
             Action.forEach(System.out::println);
            break;
         case "Documentary" :
             System.out.println("you chose: Documentary!");
             Documentary.forEach(System.out::println);
             break;
         case "Exit":
             isProgramRunning = false;
             break;
         default :
            System.out.println("Please enter a Movie genre");
      }
}

A couple things I wanted to add: I'd recommend making a Genre class that has the attributes of a String of genreName and a ArrayList. This way you make it clear, how many genres you have and can see more clearly, that the lists have something to do with the respective genre. You're also blocking the user interaction for 3 seconds, for which I don't really see a purpose. A "loading" notice makes sense if there is a lot of calculating or sorting going on in the background, which the user cannot see. You also forgot the break in the last case of the switch. This means, if you choose Documentary it's also going to fall-through to the default case.

How do i make a scanner so that I'm always able to input commands

1 Answers1