package com.example.myjavademo;
 
/**
 * 計算機的組裝過程較為復雜，并且組裝過程不固定，為了易于理解，我們把計算機組裝過程簡化為
 * 構建主機、設置操作系統、設置顯示器3步，然后通過Directer和具體Builder來構建計算機對象
 *
 */
public class BuilderDesignDemo {
 public static void main(String []args){
 //方式一
 Builder builder=new MACBookBuilder();
 Director director=new Director(builder);
 director.construct("intel","AOC");
 System.out.println(builder.create().toString());
 
 
 //方式2
 System.out.println(new MACBookBuilder().
  buildBoard("intel").buildDisplay("AOC").create().toString());
 
 
 }
}
 
/**
 * 計算機抽象類，即Product角色
 */
abstract class Computer{
 
 protected String mBoard;
 protected String mDisplay;
 protected String mOS;
 protected Computer(){
 
 }
 public void setBoard(String board){//具體什么實現進行了隱藏
 
 this.mBoard=board;
 }
 public void setDisplay(String display){//具體什么實現進行了隱藏
 this.mDisplay=display;
 }
 public abstract void setOS();
 
 @Override
 public String toString() {
 return "Computer:="+mBoard+",="+mOS+",="+mDisplay;
 }
}
 
/**
 * 具體的Computer類
 */
 
class MACBook extends Computer{
 protected MACBook(){};
 @Override
 public void setOS() {
 mOS="MAC OS X";
 }
}
 
/**
 * 抽象Builder類
 */
abstract class Builder{
 //設置主機
 public abstract Builder buildBoard(String board);
 //設置操作系統
 public abstract Builder buildOS();
 //設置顯示器
 public abstract Builder buildDisplay(String display);
 //創建Computer
 public abstract Computer create();
}
 
/**
 * 具體Builder類，MACBookBuilder
 */
class MACBookBuilder extends Builder{
 private Computer computer=new MACBook();
 
 @Override
 public Builder buildBoard(String board) {
 computer.setBoard(board);
 return this;
 }
 
 @Override
 public Builder buildOS() {
 computer.setOS();
 return this;
 }
 
 @Override
 public Builder buildDisplay(String display) {
 computer.setDisplay(display);
 return this;
 }
 
 @Override
 public Computer create() {//Mac的操作系統肯定是MAC OS的；這部分對外部隱藏
 computer.setOS();
 return computer;
 }
}
 
/**
 * Director類，負責構建Computer
 */
class Director{
 Builder builder=null;
 
 public Director(Builder builder) {
 this.builder = builder;
 }
 /**
 * 構建對象
 */
 public void construct(String board,String display){
 builder.buildBoard(board);
 builder.buildDisplay(display);
 
 }
}