What methods and tools are used in Java to implement the principle of polymorphism?

In Java, polymorphism is implemented in several ways:

1. Inheritance and method overriding (runtime polymorphism) — a base class declares a method, and subclasses override it with their own implementation. The method call depends on the actual type of the object at runtime.

2. Method overloading (compile-time polymorphism) — multiple methods with the same name but different parameters can be declared within a class.

3. Interfaces and abstract classes — allow declaring methods without implementation, which are then implemented in subclasses, providing polymorphic behavior.

Example of overriding:

class Animal {
    void sound() {
        System.out.println("Some sound");
    }
}

class Dog extends Animal {
    @Override
    void sound() {
        System.out.println("Bark");
    }
}

public class Main {
    public static void main(String[] args) {
        Animal animal = new Dog();
        animal.sound(); // Outputs "Bark"
    }
}