What is the Difference Between Abstract Class and Interface in Java?

Both Abstract Class and Interface are used for abstraction, but they have key differences in Java. Since Java 8, interfaces can have default and static methods.

Abstract Class

abstract class Vehicle {
    String brand;
    
    Vehicle(String brand) {
        this.brand = brand;
    }
    
    abstract void start();
    
    void stop() {
        System.out.println(brand + " is stopping");
    }
}

class Car extends Vehicle {
    Car(String brand) {
        super(brand);
    }
    
    @Override
    void start() {
        System.out.println(brand + " car starts");
    }
}

Interface (Java 8+)

interface Drawable {
    void draw();
    
    default void print() {
        System.out.println("Printing...");
    }
    
    static void info() {
        System.out.println("Drawable interface");
    }
}

class Circle implements Drawable {
    @Override
    public void draw() {
        System.out.println("Drawing Circle");
    }
}

Key Differences

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