java嵌套类内部和外部引用等于

public class Outer2 {

 Outer2(){
    System.out.println("Calling Outer2 constructor");
    System.out.println(this.getClass().getName() + ": Inner class reference is " + this);
    System.out.println(Outer2.this + ": Outer class reference is " + Outer2.this);
 }

 class Inner1 extends Outer2 {
    Inner1() {
        System.out.println("Calling Inner1 constructor");
        System.out.println(this.getClass().getName() + ": Inner class reference is " + this);
        System.out.println(Outer2.this + ": Outer class reference is " + Outer2.this);
    }
}

 class Inner2 extends Inner1 {
    Inner2() {
        System.out.println("Calling Inner2 constructor");
        System.out.println(this.getClass().getName() + ": Inner class reference is " + this);
        System.out.println(Outer2.this + ": Outer class reference is " + Outer2.this);
    }
}

 public static void main(String[] args) {
    new Outer2().new Inner2();
}
public class Outer2 {

 Outer2(){
    System.ou