import java.util.*;

/*

@param input Scanner Instance

@param prompt Message shown to user

@param min Minimum valid integer (inclusive)

@param max Maximum valid integer (inclusive)

@return Valid user integer input

*/

public class IntegerInput

{

public static int promptInt(Scanner input, String prompt, int min, int max) {

System.out.println(prompt);

System.out.print("> ");

boolean gaveValid = false;

int returnValue = 0;

if (max <= min) {

throw new IllegalArgumentException("Maximum parameter (" + max + ") can not be equal to or less than minimum (" + min + ").");

}

while (!gaveValid) {

if (input.hasNextInt()) {

returnValue = input.nextInt();

input.nextLine();

if (returnValue < min) {

System.out.println("[ERROR] The inputted value is less than the minimum. (" + returnValue + "<" + min + ")");

System.out.print("> ");

} else if (returnValue > max) {

System.out.println("[ERROR] The inputted value is greater than the maximum. (" + returnValue + ">" + max + ")");

System.out.print("> ");

} else {

gaveValid = true;

}

} else {

System.out.println("[ERROR] The inputted value is not an integer.");

input.nextLine();

System.out.print("> ");

gaveValid = false;

}

}

return returnValue;

}

public static void main(String[] args)

{

Scanner input = new Scanner(System.in); // put this in main

int int1 = promptInt(input, "Please enter an integer between 1 and 20, inclusive.", 1, 20);

System.out.println(int1);

input.close();

}

}