Stateful.java

public class Stateful {

  private String message = "Hello, world!";

  public void setMessage(String message) {
    this.message = message;
  }

  public void hello() {
    System.out.println(message);
  }
}

Stateless.java

public class Stateless {
  public void hello() {
    System.out.println("Hello, world!");
  }
}