检索方法或构造函数的调用者实例（而不是类） [英] Retrieve the caller instance (not class) of a method or constructor

问题描述

是否可以检索方法/构造函数的调用者实例？

Is it possible to retrieve the caller instance of a method/constructor?

此问题已经发布，但每次答案都在讨论调用者类（使用stacktrace）而不是调用者实例。
如果存在一个解决方案，那么构建对象图（使用常见的超类型）并使用默认构造函数处理父子导航可能非常方便。

This question has already been posted, but each time the answers are talking about caller Class (using stacktrace) and not caller instance. If a solution exists, it can be really convenient to build object graph (with a common super type) and handle parent child navigation with default constructor.

public class TestCallStack {
    public static class BaseClass {
        BaseClass owner;
//      //ok, this is the correct way to do it
//      public BaseClass(BaseClass owner) {
//          this.owner = owner;
//      }
        public BaseClass() {
            //this.owner = ???????; 
        }
    }
    public static class Parent extends BaseClass {
        Child child = new Child();
    }
    public static class Child extends BaseClass {
    }

    public static void main(String[] args) {
        Parent parent = new Parent();
        System.out.println(parent.child.owner==parent); // must be true
    }
}

推荐答案

你的直觉是对的 - 这是不可能的。我个人认为这是一个好的东西，因为它会使代码在重构方面相当脆弱（想象一下将一些代码拉入静态方法 - 突然间根本没有调用者对象）。

Your gut feeling is right - it's not possible. Personally I think that's a good thing, as it would make code pretty fragile with respect to refactoring (imagine pulling some code out into a static method - suddenly there's no caller object at all).

如果您想表达某种所有者关系，您应该明确地提供该所有者。

If you want to express some sort of owner relationship, you should provide that owner explicitly.

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