设计模式 -凯发ag旗舰厅登录网址下载

• separate the construction of a complex object from its representation so that the sameconstruction process can create different representations.（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。）

建造者模式通用类图

 

 

image.png

看上面图可能有点懵，举一个简单的例子

假如现在有一个生产电脑代工厂，可能会生产很多电脑品牌的组装电脑，不同的电脑品牌组装电脑的顺序可能不一样。
假如现在要为两个电脑品牌(联想、华为)组装电脑
这些部件假如只有显示器、键盘、鼠标、硬盘
需求就是这样，为不同电脑品牌组装顺序不一样，但是都提供一个公共的方法assemble()
需求有点复杂我们现在看具体代码

在computermodel中我们定义了一个setsequence方法，组装点的这几个动作要如何排布，是在这个arraylist中定义的。然后assemble()方法根据sequence定义的顺序完成指定的顺序动作

首先创建computermodel

import org.apache.commons.lang3.stringutils;import java.util.arraylist; import java.util.list;/*** @author shuliangzhao* @title: computermodel* @projectname design-parent* @description: todo* @date 2019/5/29 22:40*/ public abstract class computermodel {//sequence控制组装顺序private list sequence = new arraylist<>();protected abstract void productscreen();protected abstract void productmouse();protected abstract void productkeyboard();protected abstract void productharddisk();public void assemble() {for (string str:sequence) {if (stringutils.equals(str,"screen")) {this.productscreen();}else if (stringutils.equals(str,"mouse")) {this.productmouse();}else if (stringutils.equals(str,"keyboard")) {this.productkeyboard();}else if (stringutils.equals(str,"harddisk")) {this.productharddisk();}}}public void setsequence(list sequence) {this.sequence = sequence;} }

lenovocomputer

/*** @author shuliangzhao* @title: lenovocomputer* @projectname design-parent* @description: todo* @date 2019/5/29 22:49*/public class lenovocomputer extends computermodel {@overrideprotected void productscreen() {system.out.println("联想电脑组装屏幕");}@overrideprotected void productmouse() {system.out.println("联想电脑组装鼠标");}@overrideprotected void productkeyboard() {system.out.println("联想电脑组装键盘");}@overrideprotected void productharddisk() {system.out.println("联想电脑组装硬盘");} }

huaweicomputer

/*** @author shuliangzhao* @title: huaweicomputer* @projectname design-parent* @description: todo* @date 2019/5/29 22:51*/ public class huaweicomputer extends computermodel {@overrideprotected void productscreen() {system.out.println("华为电脑组装屏幕");}@overrideprotected void productmouse() {system.out.println("华为电脑组装鼠标");}@overrideprotected void productkeyboard() {system.out.println("华为电脑组装键盘");}@overrideprotected void productharddisk() {system.out.println("华为电脑组装硬盘");} }

computerbuilder

/*** @author shuliangzhao* @title: computerbuilder* @projectname design-parent* @description: todo* @date 2019/5/29 22:51*/ public abstract class computerbuilder {//建造一个模型，你要给我一个顺序要求，就是组装顺序public abstract void setsequence(list sequence);//设置完毕顺序后，就可以直接拿到这个电脑组装顺序public abstract computermodel getcomputermodel(); }

huaweibuilder

/*** @author shuliangzhao* @title: huaweibuilder* @projectname design-parent* @description: todo* @date 2019/5/29 22:56*/ public class huaweibuilder extends computerbuilder {private huaweicomputer huaweicomputer = new huaweicomputer();@overridepublic void setsequence(list sequence) {this.huaweicomputer.setsequence(sequence);}@overridepublic computermodel getcomputermodel() {return this.huaweicomputer;} }

lenovobuilder

/*** @author shuliangzhao* @title: lenovobuilder* @projectname design-parent* @description: todo* @date 2019/5/29 22:54*/ public class lenovobuilder extends computerbuilder {private lenovocomputer lenovocomputer = new lenovocomputer();@overridepublic void setsequence(list sequence) {lenovocomputer.setsequence(sequence);}@overridepublic computermodel getcomputermodel() {return this.lenovocomputer;} }

场景类director

/*** 场景类可以根据不同场景组装电脑* @author shuliangzhao* @title: director* @projectname design-parent* @description: todo* @date 2019/5/29 22:57*/ public class director {private list sequence = new arraylist<>();private huaweibuilder huaweibuilder = new huaweibuilder();private lenovobuilder lenovobuilder = new lenovobuilder();//组装华为a系列先屏幕、鼠标、键盘、硬盘public huaweicomputer getahuaweicomputer() {this.sequence.clear();sequence.add("screen");sequence.add("mouse");sequence.add("keyboard");sequence.add("harddisk");this.huaweibuilder.setsequence(sequence);return (huaweicomputer) this.huaweibuilder.getcomputermodel();}//组装华为b系列先鼠标、屏幕、硬盘、键盘public huaweicomputer getbhuaweicomputer() {this.sequence.clear();sequence.add("mouse");sequence.add("screen");sequence.add("harddisk");sequence.add("keyboard");this.huaweibuilder.setsequence(sequence);return (huaweicomputer) this.huaweibuilder.getcomputermodel();}//组装联想a系列先硬盘、键盘、鼠标、屏幕public lenovocomputer getalenovocomputer() {this.sequence.clear();sequence.add("harddisk");sequence.add("keyboard");sequence.add("mouse");sequence.add("screen");this.lenovobuilder.setsequence(sequence);return (lenovocomputer) this.lenovobuilder.getcomputermodel();}//组装联想b系列先键盘、鼠标、硬盘屏幕public lenovocomputer getblenovocomputer() {this.sequence.clear();sequence.add("keyboard");sequence.add("mouse");sequence.add("harddisk");sequence.add("screen");this.lenovobuilder.setsequence(sequence);return (lenovocomputer) this.lenovobuilder.getcomputermodel();} }

客户端

/*** @author shuliangzhao* @title: client* @projectname design-parent* @description: todo* @date 2019/5/29 23:07*/ public class client {public static void main(string[] args) {director director = new director();//组装华为a系列10台for (int i = 0;i<2;i ) {director.getahuaweicomputer().assemble();}//组装联想b系列10台for (int i=0;i<2;i ) {director.getblenovocomputer().assemble();}} }

运行结果

 

image.png

• 建造者模式优点：

1.具有封装性，使用建造者模式可以使客户端不必知道产品内部组成的细节。
2.建造者独立，容易扩展

• 建造者模式使用场景：

1.相同的方法，不同的执行顺序，产生不同的事件结果时，可以采用建造者模式
2.产品类非常复杂，或者产品类中的调用顺序不同产生了不同的效能，这个时候使用建
造者模式非常合适。

​​​​​​​

总结

以上是凯发ag旗舰厅登录网址下载为你收集整理的的全部内容，希望文章能够帮你解决所遇到的问题。

如果觉得凯发ag旗舰厅登录网址下载网站内容还不错，欢迎将凯发ag旗舰厅登录网址下载推荐给好友。