【设计模式】——建造者模式（10）

一、定义

建造者模式将一个复杂对象的构建与他的表示分离，使得同样的构建过程可以创建不同的表示。

二、框架运用

HttpClient框架在构建Client时就用到了建造者模式

三、实战

1、产品类

public class Product { private List<String> parts = new ArrayList<>(); public void addPart(String part) { parts.add(part); } public void show() { System.out.println("产品创建-------"); parts.forEach(p -> System.out.println("---------" + p)); } }

2、建造类

public abstract class Builder { public abstract void buildPartA(); public abstract void buildPartB(); public abstract Product getResult(); } public class ConcreteBuilder1 extends Builder { private Product product = new Product(); @Override public void buildPartA() { product.addPart("部件A"); } @Override public void buildPartB() { product.addPart("部件B"); } @Override public Product getResult() { return product; } } public class ConcreteBuilder2 extends Builder { private Product product = new Product(); @Override public void buildPartA() { product.addPart("部件X"); } @Override public void buildPartB() { product.addPart("部件Y"); } @Override public Product getResult() { return product; } }

3、指挥类

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

4、执行和结果

public class Client { public static void main(String[] args) { Builder builderA = new ConcreteBuilder1(); Builder builderB = new ConcreteBuilder2(); Director director = new Director(); director.construct(builderA); Product productA = builderA.getResult(); productA.show(); director.construct(builderB); Product productB = builderB.getResult(); productB.show(); } } Connected to the target VM, address: '127.0.0.1:56304', transport: 'socket' 产品创建------- ---------部件A ---------部件B 产品创建------- ---------部件X ---------部件Y Disconnected from the target VM, address: '127.0.0.1:56304', transport: 'socket'