工厂模式分类

1. 简单工厂模式（静态工厂模式）
2. 抽象工厂模式
3. 工厂方法模式

简单工厂模式

• 简单工厂模式也叫静态工厂模式，工厂类一般使用静态方法
• 通过接收的参数不同来返回不同的对象实例
• 但是对增加新产品无能为力，不增加代码无法扩展

public class CarFactory {
    public static Car creatCar(String name) {
        Car car = null;
        if(name.equals("benz")) {
            car = new Benz();
        }else if(name.equals("bmw")) {
            car = new BMW();
        }else if(name.equals("audi")) {
            car = new Audi();
        }
        return car;
    }
}
 
public interface Car {
    void run();
}
 
public class BMW implements Car {
    @Override
    public void run() {
        System.out.println("BMW running");
    }
}
 
 
public class Benz implements Car {
    @Override
    public void run() {
        System.out.println("Benz running");
    }
}
 
public class Audi implements Car {
    @Override
    public void run() {
        System.out.println("Audi running");
    }
}
 
 
public class Client {
    public static void main(String[] args) {
        //不用简单工厂模式的创建
        Car benz = new Benz();
        benz.run();
        Car bmw = new BMW();
        bmw.run();
        Car audi = new Audi();
        audi.run();
        System.out.println("+++++++++++++++++++++");
         
        //简单工厂
        Car benz2 = CarFactory.creatCar("benz");
        benz.run();
        Car bmw2 = CarFactory.creatCar("bmw");
        bmw.run();
        Car audi2 = CarFactory.creatCar("audi");
        audi.run();
         
    }
}

工厂方法模式

工厂方法模式，避免了简单工厂的缺点，满足了OCP（开闭原则，对扩展开放，对修改关闭）原则；
简单工厂只有一个工厂类，而工厂方法有一组实现了相同接口的工厂方法；
工厂方法模式的缺点：结构和代码复杂度高，但是可扩展性好，客户端编程难度小；

public interface Car {
    void run();
}
 
public class Audi implements Car {
    @Override
    public void run() {
        System.out.println("Audi running");
    }
 
}
 
public class Benz implements Car {
    @Override
    public void run() {
        System.out.println("Benz running");
    }
 
}
 
public class BMW implements Car {
    @Override
    public void run() {
        System.out.println("BMW running");
    }
 
}
 
public interface CarFactory {
    Car creatCar();
}
 
 
public class AudiFactory implements CarFactory {
    @Override
    public Car creatCar() {
        return new Audi();
    }
 
}
 
public class BenzFactory implements CarFactory {
    @Override
    public Car creatCar() {
        return new Benz();
    }
     
 
}
 
public class BMWFactory implements CarFactory {
    @Override
    public Car creatCar() {
        return new BMW();
    }
 
}
 
public class Client {
    public static void main(String[] args) {
        //不用简单工厂模式的创建
        Car benz = new Benz();
        benz.run();
        Car bmw = new BMW();
        bmw.run();
        Car audi = new Audi();
        audi.run();
        System.out.println("+++++++++++++++++++++");
         
        //简单工厂
        Car benz2 = new BenzFactory().creatCar();
        benz.run();
        Car bmw2 = new BMWFactory().creatCar();
        bmw.run();
        Car audi2 = new AudiFactory().creatCar();
        audi.run();
         
    }
}

抽象工厂模式

抽象工厂模式可以增加产品族，但是不可以增加新产品，纵向扩展

public interface Seat {
    void massage();
}
 
class LuxurySeat implements Seat {
 
    @Override
    public void massage() {
        System.out.println("可以自动按摩！");
    }
     
}
class LowSeat implements Seat {
 
    @Override
    public void massage() {
        System.out.println("不可以自动按摩！");
    }
     
}
 
public interface Tyre {
    void revolve();
}
 
class LuxuryTyre implements Tyre {
 
    @Override
    public void revolve() {
        System.out.println("旋转不磨损！");
    }
     
}
 
class LowTyre implements Tyre {
 
    @Override
    public void revolve() {
        System.out.println("旋转磨损！");
    }
     
}
 
public interface Engine {
    void run();
    void start();
}
 
 
class LuxuryEngine implements Engine{
 
    @Override
    public void run() {
        System.out.println("转的快！");
    }
 
    @Override
    public void start() {
        System.out.println("启动快！");
    }
     
}
 
class LowEngine implements Engine{
     
    @Override
    public void run() {
        System.out.println("转的慢！");
    }
     
    @Override
    public void start() {
        System.out.println("启动慢");
    }
     
}
 
 
public interface CarFactory {
    Engine createEngine();
    Seat createSeat();
    Tyre createTyre();
}
 
public class LowCarFactory implements CarFactory {
 
    @Override
    public Engine createEngine() {
        return new LowEngine();
    }
 
    @Override
    public Seat createSeat() {
        return new LowSeat();
    }
 
    @Override
    public Tyre createTyre() {
        return new LowTyre();
    }
 
 
}
 
public class LuxuryCarFactory implements CarFactory {
 
    @Override
    public Engine createEngine() {
        return new LuxuryEngine();
    }
 
    @Override
    public Seat createSeat() {
        return new LuxurySeat();
    }
 
    @Override
    public Tyre createTyre() {
        return new LuxuryTyre();
    }
 
 
}
 
public class Client {
 
    public static void main(String[] args) {
        CarFactory  factory = new LuxuryCarFactory();
        Engine e = factory.createEngine();
        e.run();
        e.start();    
    }
}