java 内部类与外部类实例化顺序

package Test2;

class A {

private B b = new B(this); // 1

public A() {

System.out.println("instance A"); // 4
}

public void print() {
System.out.println("invoke A"); // 2 - 2
}

private class B {
public B(A a) {
a.print(); // 2 - 1
System.out.println("instance B "); // 3
}
}
}

public class Test {
public static void main(String[] args) {
new A();
}
}