如果匿名内部类有两个外部类，如何获取外部类的引用？

Question

public class OuterClass {
    public class InnerClass{
         void test(){
         };
    }
}

class Client{
    public void x(){}
    public void lucian() {
        OuterClass.InnerClass innerClass = new OuterClass().new InnerClass(){
            void test() {
                Client.this.x();
                x();
                ******** // how can I get the reference of the OuterClass at here? ********
            }
        };
        innerClass.test();
    }
}

I know the compiler will produce a constructor for the anonymous Inner Class with two arguments,one is the Client's refrence, another one is the OuterClass, but how can I get the OuterClass's refrence like Client's refrence in methoud test() using Client.this? Not the Client.this!! But the OuterClass's refrence in Client.

Answer 1

You can't. Not with crazy reflection shenanigans, anyway. So, just write it out:

public void lucian() {
    OuterClass oc = new OuterClass();
    OuterClass.InnerClass ic = oc.new InnerClass() {
        void test() {
            Client.this.x();
            x();
            oc.x();
        }
    };
    ic.test();
}

NB: Non-static inner classes are weird and rarely correct. Beginner java coders should never use them; advanced java coders should think long and hard. In any case, your default choice for inner classes should always be that they are static.

Answer 2

You can save reference to the object of OuterClass (so far you create it anonymously):

class Client{

    private OuterClass outerClass;

    public OuterClass getOuterClass() {
        return outerClass;
    }

    public void setOuterClass(OuterClass outerClass) {
        this.outerClass = outerClass;
    }

    public void x(){
        System.out.println("===");
    }
    public void lucian() {
        OuterClass outerClass = new OuterClass();
        setOuterClass(outerClass);
        OuterClass.InnerClass innerClass = outerClass.new InnerClass(){
            void test() {
                Client1.this.x();
                x();
                System.out.println(getOuterClass());
            }
        };
        innerClass.test();
    }
    public static void main(String[] args) {
        Client client = new Client();
        client.lucian();
    }

}