工厂模式

　　一般推荐使用简单工厂模式--构建汽车接口、独特车型实现接口、工厂根据用户想要的车型常见新车返回给用户

public interface Car {
    void run();
}

public class Audi implements Car{
    @Override
    public void run() {
        System.out.println("Audi is running!");
    }
}

public class Byd implements Car{ @Override public void run() { System.out.println("Byd is running!"); } }

public class SimpleFactoryDemo {
    public static Car createCar(String type){
        Car c = null;
        if(type.equals("Audi")){
            c = new Audi();
            return c;
        }else if(type.equals("Byd")){
            c = new Byd();
            return c;
        }
        return c;
    }
}

//调用者只需调用工厂，让工厂返回对象。不需要调用者自己创建new对象。
public class Client {
    public static void main(String[] args) {
        Car c1 = SimpleFactoryDemo.createCar("Audi");
        Car c2 = SimpleFactoryDemo.createCar("Byd");
        c1.run();
        c2.run();
    }
}


输出：Audi is running!
         Byd is running!    

　　抽象工厂模式适用于产品族系列。相当于生产要都是一个系列的。每个工厂生产所需的组件不同但是一系列的。

//发动机分为好的与一般的两个系列
public interface Engine {
    void mess();
}
class AdvancedEngine implements Engine{
    @Override
    public void mess() {
        System.out.println("faster");
    }
}
class LowerEngine implements Engine{
    @Override
    public void mess() {
        System.out.println("normal");
    }
}

//镜子也分为好于一般的
public interface Mirror {
    void mess();
}
class AdvancedMirror implements Mirror{
    @Override
    public void mess() {
        System.out.println("better");
    }
}
class LowerMirror implements Mirror{
    @Override
    public void mess() {
        System.out.println("good");
    }
}

//座椅也分为好的与一般的
public interface Seat {
    void mess();
}
class AdvancedSeat implements Seat{
    @Override
    public void mess() {
        System.out.println("thick");
    }
}
class LowerSeat implements Seat{
    @Override
    public void mess() {
        System.out.println("thin");
    }
}

//汽车工厂类的行为
public interface CarFactory {
     Engine createEngine();
     Seat createSeat();
     Mirror createMirror();
}

//好的工厂创建它的好产品系列
public class AdvancedFactory implements CarFactory{
    @Override
    public Engine createEngine() {
        return new AdvancedEngine();
    }
    @Override
    public Seat createSeat() {
        return new AdvancedSeat();
    }
    @Override
    public Mirror createMirror() {
        return new AdvancedMirror();
    }
}

//一般工厂创建它的一般产品系列
public class LowerFactory implements CarFactory{
    @Override
    public Engine createEngine() {
        return new LowerEngine();
    }
    @Override
    public Seat createSeat() {
        return new LowerSeat();
    }
    @Override
    public Mirror createMirror() {
        return new LowerMirror();
    }
}

//抽象工厂创建产品
public class AbstractFactoryDemo {
    public static void main(String[] args) {
        CarFactory c = new AdvancedFactory();
        Engine e = c.createEngine();
        Mirror m = c.createMirror();
        Seat s = c.createSeat();
        e.mess();
        m.mess();
        s.mess();
    }
}

输出：faster
better
thick