New to Java - can you tell me what´s wrong on my program?

Question

Hello everyone. I started to learn Java from the course here on Sololearn. I have completed it all in a couple of hours, but I haven´t understood a lot of things. So I am taking the course again and trying to make a short program after each lesson. I just started module about OOP and made a program, where you can mix up to 3 different liquids to make yourself a custom cocktail. It works fine, but I hit a tiny problem. I want to ask user 3 times for 3 different things. The outpus should look like this:

You can have up to 3 diferent liquids in your cocktail. Type "1","2" or "3". The given slot will get overwritten.
<USER INPUT>
Type liquid - for example "soda".
<USER INPUT>
Type volume in mililitres - for example "150"
<USER INPUT>

But it firstly prints all the instructions and THEN it acceptsuser input 3 times.
Can you tell me where did I make a mistake?

Answer 1

Problematic part of my program:
System.out.println("You can have up to 3 diferent liquids in your cocktail. Type \"1\",\"2\" or \"3\". The given slot will get overwritten.");
Scanner n = new Scanner(System.in);
System.out.println("Type liquid - for example \"soda\"");
Scanner lq = new Scanner(System.in);
System.out.println("Type volume in mililitres - for example \"150\"");
Scanner vl = new Scanner(System.in);

Answer 2

Thank you very much. This solved another my problem too.

Answer 3

I have one more problem. When I write

String input = new Scanner(System.in).next();

it throws me warning:

Resource leak '<unassigned Closeable value>' is never closed!

What can I do about this? I have the same problem alway, when I use Scanner.

Answer 4

String input = new Scanner(System.in).next();

Answer 5

import liquidMixer.*;
import java.util.Scanner;

public class program {
public static void main(String[] args) {
int lqdPrint;
Glass glss = new Glass();
while(true) {
System.out.println("What do you want to do?");
String input = new Scanner(System.in).next();
switch(input) {
case "addLiquid":
System.out.println("You can have up to 3 diferent liquids in your cocktail. Type \"1\",\"2\" or \"3\". The given slot will get overwritten.");
int n = new Scanner(System.in).nextInt();
System.out.println("Type liquid - for example \"soda\"");
String lq = new Scanner(System.in).next();
System.out.println("Type volume in mililitres - for example \"150\"");
int vl = new Scanner(System.in).nextInt();
glss.setLiquid(n, lq);
glss.setVolume(n, vl);
System.out.println("Liquid number "+n+" has been changed to "+vl+" of "+lq);
continue;
case "printLiquid":
System.out.println("Which liquid do you want informations about?");
Scanner lqPrint = new Scanner(System.in);
lqdPrint=lqPrint.nextInt();
glss.printLiquid(lqdPrint);
continue;
case "printContent":
glss.printContent();
continue;
case "help":
System.out.println("Possible options: addLiquid, printLiquid, printContent, help, exit");
continue;
case "exit":
break;
default:
System.out.println("Invalid option. Possible options: addLiquid, printLiquid, printContent, help, exit");
continue;
}
break;
}
}
}

Answer 6

OK, thank you.