如何使用返回类引用的方法创建匿名类

Question

I want to create an anonymous class using a method that returns an instance of a class

class FirstClass {
    public FirstClass() {
        System.out.println("First class created");
    }
}

class SecondClass {
    public SecondClass() {
        System.out.println("Second class created");
    }
    public FirstClass getFirstClass() {
        return new FirstClass();
    }
}

public class Ex1 {
    public FirstClass getFirstClass() {
        return new FirstClass();
    }
    public static void main(String[] args) {
        //here is the problem
        Object obj = new SecondClass().getFirstClass() {
            {
                System.out.println("Anonymous class created");
            }
        };
    }
}

I expect program to work by creating the anonymous class, but it gives me a syntax error. Any solutions or workarounds are accepted. Thanks

Answer 1

You cannot create an anonymous class based on return value of a method. Anonymous classes can only be created upon creation of the object , meaning, it can only be created using a constructor.

Your best bet would be to just create FirstClass directly, and override the initializer, like so:

new FirstClass() {
    {
        System.out.println("This is from inside anon!");
    }
};