Retrieve the caller instance (not class) of a method or constructor
Is it possible to retriev开发者_StackOverflow社区e the caller instance of a method/constructor?
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
}
}
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).
If you want to express some sort of owner relationship, you should provide that owner explicitly.
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