How to use popup() and input() in Java programs?

Hi,
I have tried to write practice programs importing SikulixAPI.jar in both Jython and Java in Eclipse IDE.

In Jython code in Eclipse, I am able to directly call popup() and input() methods and get them to work while running.

But in Java code, I am not sure on how to use popup() and input() methods.

I have tried this :

import org.sikuli.script.*;
public class main {

 public static void main(String[] args) {
          {
                  Screen s = new Screen();
                  SikuliScript b = new SikuliScript();
                          s.click("starticon.png");
                          b.popup("hello"); }}

The error is "SikuliScript cannot be resolved to a type"

Is it possible to use popup, input, alert functions in java code while using SikulixAPI.jar?