Develop a Java program that demonstrates inheritance between two classes:the superclass Animal and its subclass Dog.

Sure, here is a simple example of a Java program that demonstrates inheritance between two classes: the superclass Animal and its subclass Dog.

// This is the superclass Animal
public class Animal {
    String name;
    int age;

    public void eat() {
        System.out.println(name + " is eating");
    }

    public void sleep() {
        System.out.println(name + " is sleeping");
    }
}

// This is the subclass Dog
public class Dog extends Animal {
    String breed;

    public void bark() {
        System.out.println(name + " is barking");
    }
}

// This is the main class
public class Main {
    public static void main(String[] args) {
        Dog myDog = new Dog();
        myDog.name = "Rex";
        myDog.age = 5;
        myDog.breed = "Labrador";

        myDog.eat();
        myDog.sleep();
        myDog.bark();
    }
}

In this program, the Dog class is a subclass of the Animal class. This means that Dog inherits all the fields and methods of Animal. The Dog class can also define additional fields and methods, such as breed and bark(), that are not present in Animal.

In the Main class, we create an instance of Dog and call its methods. Since Dog is a subclass of Animal, it can use the eat() and sleep() methods defined in Animal, as well as the bark() method defined in Dog.