1. 建造者模式

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1.1 引入

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1.2 定义

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1.3 结构

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1.3.1 典型的复杂对象类代码

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1.3.2 典型的抽象建造者类代码

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1.3.3 典型的具体建造者类代码

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1.3.4 典型的指挥者类代码

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1.4 实例: 创建共享单车

创建共享单车:

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1.4.1 Bike 自行车类：产品类

package com.tian.pattern.builder.demo1;/*** 自行车类：产品类*/
public class Bike {private String frame;//车架private String seat;//车座public String getFrame() {return frame;}public void setFrame(String frame) {this.frame = frame;}public String getSeat() {return seat;}public void setSeat(String seat) {this.seat = seat;}
}

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1.4.2 Builder 建造者类：抽象建造者类

package com.tian.pattern.builder.demo1;/*** 建造者类：抽象建造者类*/
public abstract class Builder {//声明Bike类型的变量，并进行赋值protected Bike bike = new Bike();public abstract void buildFrame();public abstract void buildSeat();//构建自行车的方法public abstract Bike createBike();
}

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1.4.3 MobileBuilder 摩拜单车建造者类：具体建造者类

package com.tian.pattern.builder.demo1;/*** MobileBuilder 摩拜单车建造者类：具体建造者类*/
public class MobileBuilder extends Builder {public void buildFrame() {bike.setFrame("碳纤维车架");}public void buildSeat() {bike.setSeat("真皮车座");}public Bike createBike() {return bike;}
}

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1.4.4 OfoBuilder ofo单车建造者类：具体建造者类

package com.tian.pattern.builder.demo1;/*** OfoBuilder ofo单车建造者类：具体建造者类*/
public class OfoBuilder extends Builder {public void buildFrame() {bike.setFrame("铝合金车架");}public void buildSeat() {bike.setSeat("橡胶车座");}public Bike createBike() {return bike;}
}

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1.4.5 Director 指挥者类

package com.tian.pattern.builder.demo1;/*** 指挥者类*/
public class Director {//声明builder类型的变量private Builder builder;public Director(Builder builder) {this.builder = builder;}//组装自行车的功能public Bike construct() {builder.buildFrame();builder.buildSeat();return builder.createBike();}
}

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1.4.6 Client 客户端类(测试类)

package com.tian.pattern.builder.demo1;/*** 客户端类(测试类)*/
public class Client {public static void main(String[] args) {//创建指挥者对象Director director = new Director(new MobileBuilder());//让指挥者只会组装自行车Bike bike = director.construct();System.out.println(bike.getFrame());System.out.println(bike.getSeat());}
}

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1.4.7 运行结果

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1.5 可以简化系统结构，可以把指挥者类和抽象建造者进行结合

上面示例是 Builder模式的常规用法，指挥者类 Director在建造者模式中具有很重要的作用，它用于指导具体构建者如何构建产品，控制调用先后次序，并向调用者返回完整的产品类，但是有些情况下需要简化系统结构，可以把指挥者类和抽象建造者进行结合（把指挥者类的功能集成到抽象建造者类，然后删去指挥者类）

说明:

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1.6 模式优缺点分析

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1.6.1 优点

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1.6.2 缺点

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1.7 模式适用环境

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