A sample Java program using GUI with javax.swing package.

GUIInput.java

import javax.swing.*;
public class GUIInput {
	public static void main(String[] args) {
		String name = JOptionPane.showInputDialog("What's your name?");
		String ageString = JOptionPane.showInputDialog("What's your age?");
		int age = Integer.valueOf(ageString);
		System.out.print("Hello " + name);
		System.out.println("You are going to be " + (age + 1) + " next year");
	}
}