23种设计模式之建造者模式

建造者模式（Builder）：将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示。

package designMode.builder;

import java.util.LinkedList;
import java.util.List;

class Product {

    List<String> parts = new LinkedList<String>();

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

    public void show(){
        System.out.println("产品创建...");
        for (String str : parts) {
            System.out.println(str);
        }
    }
}

package designMode.builder;

interface Builder {

    void buildPartA();

    void buildPartB();

    Product getResult();
}

package designMode.builder;

class ConcreteBuilder1 implements Builder{

    private Product product = new Product();

    @Override
    public void buildPartA() {
        product.add("部件A");
    }

    @Override
    public void buildPartB() {
        product.add("部件B");
    }

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

}
class ConcreteBuilder2 implements Builder{

    private Product product = new Product();

    @Override
    public void buildPartA() {
        product.add("部件X");
    }

    @Override
    public void buildPartB() {
        product.add("部件Y");
    }

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

package designMode.builder;

class Director {

    public void construct(Builder builder){
        builder.buildPartA();
        builder.buildPartB();
    }
}

package designMode.builder;

class Test {

    public static void main(String[] args) {
        Director director = new Director();
        Builder b1 = new ConcreteBuilder1();
        Builder b2 = new ConcreteBuilder2();

        director.construct(b1);
        Product p1 = b1.getResult();
        p1.show();

        director.construct(b2);
        Product p2 = b2.getResult();
        p2.show();
    }
}