👀 Views: 2 💬 Answers: 1 📅 Created: 2025-06-07

java oop method-references abstract-classes

I'm trying to figure out Hey everyone, I'm running into an issue that's driving me crazy. I tried several approaches but none seem to work... I'm working with a question when trying to use method references with an abstract class in Java 17. I have an abstract class `Animal` with a method `makeSound()`, and a concrete subclass `Dog` that implements this method. I'm trying to pass a method reference to a List of `Animal` objects, but I'm getting a compilation behavior that suggests the method reference does not match the expected functional interface. Here's the code snippet for clarification: ```java import java.util.Arrays; import java.util.List; abstract class Animal { abstract void makeSound(); } class Dog extends Animal { @Override void makeSound() { System.out.println("Bark!"); } } public class Main { public static void main(String[] args) { List<Animal> animals = Arrays.asList(new Dog(), new Dog()); animals.forEach(Animal::makeSound); // This line causes a compilation behavior } } ``` The behavior I receive is: `want to find symbol - method makeSound()`. I've checked the method signatures, and I think they match the expected functional interface but the compiler seems to disagree. I've tried replacing the method reference with a lambda expression like this: ```java animals.forEach(animal -> animal.makeSound()); ``` This works perfectly, but I want to understand why the method reference doesn't. Is there something specific about method references in relation to abstract classes that I'm missing? Any guidance on this would be greatly appreciated! This is part of a larger application I'm building. Thanks in advance! For context: I'm using Java on Linux. Is there a better approach? What would be the recommended way to handle this?