Design Pattern: Abstract Factory Pattern in Java

Abstract Factory pattern is used to generate multiple factory generators.

Check Details of Abstract Factory Pattern

This article demonstrates Abstract Factory pattern implementations in Java. Check the following examples.

Examples

Here are some Abstract Factory Pattern examples in Java-

Example #1: Transport

Let’s take the example of a transport system. Take a look at the class diagram first.

Transport Factory Interface

// Transport.java

package com.bigboxcode;

public interface Transport {

    void start();

    void stop();

    void repair();

}

Bicycle Class

// Bicycle.java

package com.bigboxcode;

public class Bicycle implements Transport {
    @Override
    public void start() {
        System.out.println("Bicycle Started");
    }

    @Override
    public void stop() {
        System.out.println("Bicycle Stopped");
    }

    @Override
    public void repair() {
        System.out.println("Bicycle Repair");
    }
}

Motorcycle Class

// Motorcycle.java

package com.bigboxcode;

public class Motorcycle implements Transport {
    @Override
    public void start() {
        System.out.println("Motorcycle Started");
    }

    @Override
    public void stop() {
        System.out.println("Motorcycle Stopped");
    }

    @Override
    public void repair() {
        System.out.println("Motorcycle Repair");
    }
}

Car Class

// Car.java

package com.bigboxcode;

public class Car implements Transport {
    @Override
    public void start() {
        System.out.println("Car Started");
    }

    @Override
    public void stop() {
        System.out.println("Car Stopped");
    }

    @Override
    public void repair() {
        System.out.println("Car Repair");
    }
}

Truck Class

// Truck.java

package com.bigboxcode;

public class Truck implements Transport {
    @Override
    public void start() {
        System.out.println("Truck Started");
    }

    @Override
    public void stop() {
        System.out.println("Truck Stopped");
    }

    @Override
    public void repair() {
        System.out.println("Truck Repair");
    }
}

Abstract Transport Factory Interface

// AbstractTransportFactory.java

package com.bigboxcode;

public interface AbstractTransportFactory {

    Transport getTransport(String type);
}

Two Wheel Transport Factory Class

// TwoWheelTransportFactory.java

package com.bigboxcode;

public class TwoWheelTransportFactory implements AbstractTransportFactory{
    @Override
    public Transport getTransport(String type) {

        if (type.equalsIgnoreCase("bicycle")) {
            return new Bicycle();
        }

        if (type.equalsIgnoreCase("motorcycle")) {
            return new Motorcycle();
        }

        return null;
    }
}

Four Wheel Transport Factory Class

// FourWheelTransportFactory.java

package com.bigboxcode;

public class FourWheelTransportFactory implements AbstractTransportFactory{
    @Override
    public Transport getTransport(String type) {

        if (type.equalsIgnoreCase("car")) {
            return new Car();
        }

        if (type.equalsIgnoreCase("truck")) {
            return new Truck();
        }

        return null;
    }
}

Factory Producer Class

// FactoryProducer.java

package com.bigboxcode;

public class FactoryProducer {

    public static AbstractTransportFactory getFactory(int numberOfWheels) {

        if (numberOfWheels == 2) {
            return new TwoWheelTransportFactory();
        }

        if (numberOfWheels == 4) {
            return new FourWheelTransportFactory();
        }

        return null;
    }
}

Demo

// Main.java

package com.bigboxcode;

public class Main {

    public static void main(String[] args) {

        AbstractTransportFactory transportFactory1 = FactoryProducer.getFactory(2);
        Transport transport1 = transportFactory1.getTransport("bicycle");

        transport1.start();

        AbstractTransportFactory transportFactory2 = FactoryProducer.getFactory(4);
        Transport transport2 = transportFactory2.getTransport("truck");

        transport2.start();
    }
}

Output