My main method:

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    String string1;
    string1 = input.next();

    LargeInteger firstInt = new LargeInteger(string1);

    System.out.printf("First integer: %s \n", firstInt.display());
}

LargeInteger class:

public class LargeInteger {

    private int[] intArray;

    //convert the strings to array
    public LargeInteger(String s) {
        for (int i = 0; i < s.length(); i++) {
            intArray[i] = Character.digit(s.charAt(i), 10); // in base 10
        }
    }

    //display the strings
    public String display() {
        String result = "";

        for (int i = 0; i < intArray.length; i++) {
            result += intArray[i];
        }
        return result.toString();
    }
}