JAVA设计模式5：建造者模式，将对象的构建过程与其表示分离

// 产品类：汽车
class Car {
    private String brand;
    private String color;
    private int wheels;
    
    public void setBrand(String brand) {
        this.brand = brand;
    }
    
    public void setColor(String color) {
        this.color = color;
    }
    
    public void setWheels(int wheels) {
        this.wheels = wheels;
    }
    
    public void showInfo() {
        System.out.println("Car brand: " + brand);
        System.out.println("Car color: " + color);
        System.out.println("Number of wheels: " + wheels);
    }
}

// 抽象建造者类
abstract class CarBuilder {
    protected Car car;
    
    public Car getCar() {
        return car;
    }
    
    public abstract void buildBrand();
    
    public abstract void buildColor();
    
    public abstract void buildWheels();
}

// 具体建造者类：SUV汽车建造者
class SuvCarBuilder extends CarBuilder {
    public SuvCarBuilder() {
        car = new Car();
    }
    
    public void buildBrand() {
        car.setBrand("SUV");
    }
    
    public void buildColor() {
        car.setColor("Black");
    }
    
    public void buildWheels() {
        car.setWheels(4);
    }
}

// 具体建造者类：跑车建造者
class SportsCarBuilder extends CarBuilder {
    public SportsCarBuilder() {
        car = new Car();
    }
    
    public void buildBrand() {
        car.setBrand("Sports Car");
    }
    
    public void buildColor() {
        car.setColor("Red");
    }
    
    public void buildWheels() {
        car.setWheels(4);
    }
}

// 指导者类：负责控制建造过程
class CarDirector {
    private CarBuilder carBuilder;
    
    public void setCarBuilder(CarBuilder carBuilder) {
        this.carBuilder = carBuilder;
    }
    
    public Car getCar() {
        return carBuilder.getCar();
    }
    
    public void constructCar() {
        carBuilder.buildBrand();
        carBuilder.buildColor();
        carBuilder.buildWheels();
    }
}

// 客户端类
public class BuilderPatternExample {
    public static void main(String[] args) {
        CarDirector director = new CarDirector();
        
        CarBuilder suvBuilder = new SuvCarBuilder();
        director.setCarBuilder(suvBuilder);
        director.constructCar();
        Car suvCar = director.getCar();
        suvCar.showInfo();
        
        CarBuilder sportsCarBuilder = new SportsCarBuilder();
        director.setCarBuilder(sportsCarBuilder);
        director.constructCar();
        Car sportsCar = director.getCar();
        sportsCar.showInfo();
    }
}