大话设计模式----建造者模式

public class Product {
    List<String> parts = new ArrayList<>();

    public void addParts(String part){
        parts.add(part);
    }

    public void show(){
        parts.forEach(System.out::println);
    }
}

public interface Builder {

    void builderPartA();

    void builderPartB();

    Product getProduct();
}

public class ConcreteBuilderA implements Builder {

    Product product = new Product();

    public ConcreteBuilderA() {
        System.out.println("======ConcreteBuilderA=====");
    }

    @Override
    public void builderPartA() {
        product.addParts("部件A");
    }

    @Override
    public void builderPartB() {
        product.addParts("部件B");
    }

    @Override
    public Product getProduct() {
        return product;
    }
}

public class ConcreteBuilderB implements Builder {

    Product product = new Product();

    public ConcreteBuilderB() {
        System.out.println("======ConcreteBuilderB=====");
    }

    @Override
    public void builderPartA() {
        product.addParts("部件X");
    }

    @Override
    public void builderPartB() {
        product.addParts("部件Y");
    }

    @Override
    public Product getProduct() {
        return product;
    }
}

public class Director {
    public void initBuilder(Builder builder){
        builder.builderPartA();
        builder.builderPartB();
    }
}

public class Test {

    public static void main(String[] args) {
        Director director = new Director();
        ConcreteBuilderA concreteBuilderA = new ConcreteBuilderA();
        director.initBuilder(concreteBuilderA);
        concreteBuilderA.getProduct().show();

        ConcreteBuilderB concreteBuilderB = new ConcreteBuilderB();
        director.initBuilder(concreteBuilderB);
        concreteBuilderB.getProduct().show();
    }
    /** result
     * ======ConcreteBuilderA=====
     * 部件A
     * 部件B
     * ======ConcreteBuilderB=====
     * 部件X
     * 部件Y
     */
}