设计模式学习笔记--简单工厂模式和工厂模式

Posted 2020-10-22 yirain1992

老生长谈的两个设计模式了，这里把这两个设计模式对比着来总结一下。

什么是简单工厂模式？

简单工厂模式：根据传入工厂类的参数动态决定要创建哪一个产品类的实例。

UML图如下（以实现一个计算器为例）：

     

 简单工厂模式的Java代码实现如下：

 

 1 package designPattern;
 2 /**
 3  * 简单工厂模式
 4  * @author yiRain
 5  *
 6  */
 7 public class SimpleFactory {
 8  
 9     public static void main(String[] args){
10         
11         double numberA = 6,numberB = 2;
12         
13         FactoryOperation factoryOperation = new FactoryOperation();
14         Operation add = factoryOperation.CreateOperate(‘+‘);
15         double addResult = add.GetResult(numberA, numberB);
16         
17         Operation sub = factoryOperation.CreateOperate(‘-‘);
18         double subResult = sub.GetResult(numberA, numberB);
19         
20         System.out.println("addResult="+addResult+",subResult="+subResult);
21     }
22 }
23 
24 /**
25  * 
26  * 运算类
27  *
28  */
29 abstract class Operation{
30     public double numberA, numberB;
31     public abstract double GetResult(double numberA,double numberB);
32 }
33 
34 /**
35  * 
36  * 加法类
37  *
38  */
39 class addOperation extends Operation{
40 
41     @Override
42     public double GetResult(double numberA, double numberB) {
43         // TODO Auto-generated method stub
44         return numberA+numberB;
45     }
46     
47 }
48 
49 /**
50  * 
51  * 减法类
52  *
53  */
54 class subOperation extends Operation{
55 
56     @Override
57     public double GetResult(double numberA, double numberB) {
58         // TODO Auto-generated method stub
59         return numberA-numberB;
60     }
61     
62 }
63 
64 /**
65  * 
66  * 工厂类
67  *
68  */
69 class FactoryOperation{
70     public Operation CreateOperate(char type){
71         switch (type) {
72         case ‘+‘:
73             Operation add = new addOperation();
74             return add;
75         case ‘-‘:
76             Operation sub = new subOperation();
77             return sub;
78         default:
79             return null;
80         }
81     }
82 }