EP6 Calculator

package com.classicpork.tutorial;

import static java.lang.System.err;
import static java.lang.System.out;
import static java.awt.event.KeyEvent.*;

import java.awt.AWTException;
import java.awt.Robot;
import java.util.Scanner;

public class YoutubeCalculatorEp6 {

    public static final Scanner reader = new Scanner(System.in);

    public static void main(String[] args) {

        double a, b;
        int o;
        double result = 0;

        out.print("Enter the First number: ");
        a = get();
        wipe();

        out.print("Enter the Second number: ");
        b = get();
        wipe();

        out.println("Enter the Operation: 1 Add | 2 Subtract | 3 Multiply | 4 Divide");
        o = getOperation();
        wipe();

        switch (o) {

        case 1:
            result = a + b;
            out.println(a + " + " + b + " = " + result);
            break;
        case 2:
            result = a - b;
            out.println(a + " - " + b + " = " + result);
            break;
        case 3:
            result = a * b;
            out.println(a + " * " + b + " = " + result);
            break;
        case 4:
            result = a / b;
            out.println(a + " / " + b + " = " + result);
            break;
        default:
            result = 0;
            break;

        }

    }

    public static double get() {

        try {
            double returnValue = Double.parseDouble(reader.nextLine());
            return returnValue;
        } catch (Exception e) {

            System.err.println("The value you have entered is not a valid number");
            System.err.println("Please enter the value again");
            double result = get();
            return result;

        }

    }

    public static int getOperation() {

        try {
            int returnValue = Integer.parseInt(reader.nextLine());

            if (returnValue > 4 || returnValue < 1) {
                err.println("The Operation must be from 1 ~ 4");
                returnValue = getOperation();
            }

            return returnValue;
        } catch (Exception e) {

            System.err.println("The value you have entered is not a valid number");
            System.err.println("Please enter the value again");
            int result = getOperation();
            return result;

        }

    }

    public static void wipe() {
        try {
            Thread.sleep(10);
            try {
                wipeConsole();
            } catch (AWTException e) {
                e.printStackTrace();
            }
        } catch (InterruptedException e1) {
            e1.printStackTrace();
        }
    }

    public static void wipeConsole() throws AWTException {
        Robot robbie = new Robot();

        robbie.keyPress(VK_SHIFT);
        robbie.keyPress(VK_F10);
        robbie.keyRelease(VK_SHIFT);
        robbie.keyRelease(VK_F10);
        robbie.keyPress(VK_R);
        robbie.keyRelease(VK_R);
    }

}