Defining references to inner classes : Nested Classes « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. Nested Classes

public class MainClass {
  class A {
    private int i = 11;

    public int value() {
      return i;
    }
  }

  class B {
    private String label;

    B(String whereTo) {
      label = whereTo;
    }

    String readLabel() {
      return label;
    }
  }

  public B to(String s) {
    return new B(s);
  }

  public A cont() {
    return new A();
  }

  public void ship(String dest) {
    A c = cont();
    B d = to(dest);
    System.out.println(d.readLabel());
  }

  public static void main(String[] args) {
    MainClass p = new MainClass();
    p.ship("A");
    MainClass q = new MainClass();

    MainClass.A c = q.cont();
    MainClass.B d = q.to("A");
  }
}