抽象工厂模式

上篇说到简单工厂和工厂方法，她们一次只能创建一个产品，由于这种局限性，所以这里引入抽象工厂，用来完成一堆产品（产品族）的创建。

/**
 * 汽车类
 *
 */
class Car {
    
    private Engine engine;
    private Body body;
    private Seat seat;
    private Tyre tyre;
    public Engine getEngine() {
        return engine;
    }
    public void setEngine(Engine engine) {
        this.engine = engine;
    }
    public Body getBody() {
        return body;
    }
    public void setBody(Body body) {
        this.body = body;
    }
    public Seat getSeat() {
        return seat;
    }
    public void setSeat(Seat seat) {
        this.seat = seat;
    }
    public Tyre getTyre() {
        return tyre;
    }
    public void setTyre(Tyre tyre) {
        this.tyre = tyre;
    }
    /**
     *提供toString方便输出
     */
    @Override
    public String toString() {
        return engine.getName() + "-" + body.getName() + "-" +seat.getName()
        + "-" + tyre.getName();
    }
}

/**
 *引擎类
 *
 */
class Engine{
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    
}
/**
 * 车身类
 *
 */
class Body{
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}
/**
 * 座位
 *
 */
class Seat{
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}
/**
 * 轮胎类
 *
 */
class Tyre{
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

这个汽车拥有引擎，车身，座位，和轮胎四个属性，假设现在需要高端和低端两种车，那么构造车的配件就应该分为高端和低端的。

/**
 * 汽车配件工厂
 *
 */
public interface Factory {

    /**
     * 制造引擎
     */
    Engine createEngine();
    /**
     * 制造车身
     */
    Body createBody();
    /**
     * 制造座位
     */
    Seat createSeat();
    /**
     * 制造轮子
     */
    Tyre createTyre();
}

具体的实现

/**
 * 低端工厂
 *
 */
public class LowFactory implements Factory {

    @Override
    public Engine createEngine() {
        Engine e = new Engine();
        e.setName("低端引擎就是差");
        return e;
    }

    @Override
    public Body createBody() {
        Body body = new Body();
        body.setName("低端车身就是难看");
        return body;
    }

    @Override
    public Seat createSeat() {
        Seat seat = new Seat();
        seat.setName("低端座位太硬");
        return seat;
    }

    @Override
    public Tyre createTyre() {
        Tyre tyre = new Tyre();
        tyre.setName("估计开几圈就坏了");
        return tyre;
    }

}

/**
 * 高端工厂
 */
public class HighFactory implements Factory {

    @Override
    public Engine createEngine() {
        Engine e = new Engine();
        e.setName("高端引擎就是棒");
        return e;
    }

    @Override
    public Body createBody() {
        Body body = new Body();
        body.setName("极其华丽的车身");
        return body;
    }

    @Override
    public Seat createSeat() {
        Seat seat = new Seat();
        seat.setName("舒服的座位");
        return seat;
    }

    @Override
    public Tyre createTyre() {
        Tyre tyre = new Tyre();
        tyre.setName("绕地球五圈的轮子");
        return tyre;
    }

}

/**
 * 测试类
 *
 */
class Client {
    
    public static void main(String[] args) {
        Factory factory = new LowFactory();
        //Factory factory = new HighFactory();
        Car car = new Car();
        car.setEngine(factory.createEngine());
        car.setBody(factory.createBody());
        car.setSeat(factory.createSeat());
        car.setTyre(factory.createTyre());
        System.out.println(car);
    }
}

运行结果：低端引擎就是差-低端车身就是难看-低端座位太硬-估计开几圈就坏了