【java设计模式】【创建模式Creational Pattern】建造模式Builder Pattern

 package com.tn.pattern;

 public class Client {
     public static void main(String[] args) {
         Director director=Director.getInstance();
         director.construct(new ConcreteBuilder1());
         director.construct(new ConcreteBuilder2());
     }
 }

 class Director{
     static Director director;
     private Director(){}
     public static Director getInstance(){
         if(director==null)
             director=new Director();
         return director;
     }
     public void construct(Builder builder){
         builder.buildPart1();
         builder.buildPart2();
     }
 }

 interface Builder{
     void buildPart1();
     void buildPart2();
     Product retrieveResult();
 }

 class ConcreteBuilder1 implements Builder{
     Product product;
     @Override
     public void buildPart1() {
         System.out.println("ConcreteBuilder1.buildPart1()");
         product=new Product1();
     }

     @Override
     public void buildPart2() {}

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

 class ConcreteBuilder2 implements Builder{
     Product product;
     @Override
     public void buildPart1() {}

     @Override
     public void buildPart2() {
         System.out.println("ConcreteBuilder2.buildPart2()");
         product=new Product2();
     }

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

 interface Product{}

 class Product1 implements Product{
     public Product1(){
         System.out.println("Product1.Product1()");
     }
 }

 class Product2 implements Product{
     public Product2(){
         System.out.println("Product2.Product2()");
     }
 }