Creating 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;
    }
  }

  // Using inner classes looks just like
  // using any other class, within MainClass:
  public void ship(String dest) {
    A c = new A();
    B d = new B(dest);
    System.out.println(d.readLabel());
  }

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