interface Incrementable {

     void increment();

 }

 class Callee1 implements Incrementable {

     private int i = 0;

     @Override

     public void increment() {

         i++;

         System.out.println(i);

     }

 }

 class MyIncrement {

     public void increment() {

         System.out.println("Other operation");

     }

     static void f(MyIncrement mi) {

         mi.increment();

     }

 }

 class Callee2 extends MyIncrement {

     private int i = 0;

     @Override

     public void increment() {

         super.increment();

         i++;

         System.out.println(i);

     }

     private class Closure implements Incrementable {

         @Override

         public void increment() {

             Callee2.this.increment();

         }

     }

     Incrementable callBack() {

         return new Closure();

     }

 }

 class Caller {

     private Incrementable callbackReference;

     Caller(Incrementable callbackReference) {

         this.callbackReference = callbackReference;

     }

     void go() {

         callbackReference.increment();

     }

 }

 /**

  * 关键字: 内部类应用, 闭包(Closure)<br/>

  * 1.闭包是一个可调用的对象(通过Callback)，它记录了一些信息，这些信息来自于创建它的作用域<br/>

  */

 public class Test007 {

     public static void main(String[] args) {

         Callee1 c1 = new Callee1();

         c1.increment(); //

         Callee2 c2 = new Callee2();

         MyIncrement.f(c2); // Other operation|1

         Caller caller1 = new Caller(c1);

         caller1.go(); //

         Caller caller2 = new Caller(c2.callBack());

         caller2.go(); // Other operation|2

     }

 }

 class Egg2 {

     protected class Yolk {

         public Yolk() {

             System.out.println("Egg2.Yolk()");

         }

         public void f() {

             System.out.println("Egg2.Yolk.f()");

         }

     }

     private Yolk y = new Yolk();

     public Egg2() {

         System.out.println("New Egg2()");

     }

     public void insertYolk(Yolk yy) {

         y = yy;

     }

     public void g() {

         y.f();

     }

 }

 class Test008Sub extends Egg2 {

     public Test008Sub() {

         System.out.println("AA");

         insertYolk(new Yolk());

     }

     public class Yolk extends Egg2.Yolk {

         public Yolk() {

             System.out.println("BigEgg2.Yolk()");

         }

         public void f() {

             System.out.println("BigEgg2.Yolk.f()");

         }

     }

 }

 // 复杂情况下的调用顺序

 public class Test008 {

     public static void main(String[] args) {

         new Test008Sub().g();

         // Egg2.Yolk()

         // New Egg2()

         // AA

         // Egg2.Yolk()

         // BigEgg2.Yolk()

         // BigEgg2.Yolk.f()

     }

 }