java - getting parent object without passing its reference

Question

Is there a way to get the parent object which is aaaa in this case without passing it explictly to B?

class A {
    B b = new B();
}

class B {
    public void getParent(){
}

A aaaa = new A();

Answer 1

您可以将 aaaa 作为参数传递给 B 的构造函数

class A {
    B b = new B(this);
}

A aaaa = new A();

class B {
    private A parent;
    public B(A parent) {
        this.parent = parent;
    }
}

Answer 2

如果您的意思是创建当前实例的对象（而不是持有引用的对象，因为可能有很多对象引用该对象），您可以导航调用堆栈以在构造函数中找到实例化对象。