Make if statement

Make if statement

import java.util.Scanner;
public class Random {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Welcome. Please enter three numbers!");
System.out.println("Enter your first number: ");
int x = scan.nextInt();
System.out.println("Enter your second number: ");
int y = scan.nextInt();
System.out.println("Enter your third number: ");
int u = scan.nextInt();
int total = x + y + u;
System.out.println("The total of all your choosen numbers are: " +
total);
if() {
System.out.println("Sorry, you cant print out a double value.");
}
}
}
I want to make the if statement to print out an error if the user inputs a
double value, such as 2,7. What should I do?