重构-多态取代条件表达式

  1 package refactoring;
  2 
  3 /**
  4  * @title Object oriented polymorphism
  5  * @description 面向对象多态取代switch
  6  * @author LZH
  7  * @date 2016-8-2 下午10:48:51
  8  */
  9 public class OOPReplaceSwitch {
 10 
 11     public static void main(String[] args) {
 12 
 13         int employeeType = 3;
 14 
 15         double salary = EmployeeFactory.getInstance(employeeType)
 16                 .getMonthSalary();
 17 
 18         System.out.println(String.format("薪资：%s 元", salary));
 19     }
 20 }
 21 
 22 /**
 23  * @title EmployeeType
 24  * @description 员工类型
 25  * @author LZH
 26  * @date 2016-8-2 下午10:28:33
 27  */
 28 enum EmployeeType {
 29 
 30     /** 工程师 */
 31     ENGINNER(1),
 32 
 33     /** 销售员 */
 34     SALESMAN(2),
 35 
 36     /** 经理 */
 37     MANAGER(3);
 38 
 39     private int type;
 40 
 41     private EmployeeType(int type) {
 42         this.type = type;
 43     }
 44 
 45     public int getType() {
 46         return type;
 47     }
 48 }
 49 
 50 /**
 51  * @title EmployeeFactory
 52  * @description 员工工厂类
 53  * @author LZH
 54  * @date 2016-8-2 下午10:20:45
 55  */
 56 class EmployeeFactory {
 57 
 58     /**
 59      * 根据员工类型获取具体员工实例
 60      * 
 61      * @param employeeType
 62      * @return
 63      */
 64     public static Employee getInstance(int employeeType) {
 65         
 66         if (employeeType == EmployeeType.ENGINNER.getType()) {
 67             return new Enginner();
 68         }
 69 
 70         if (employeeType == EmployeeType.SALESMAN.getType()) {
 71             return new Salesman();
 72         }
 73 
 74         if (employeeType == EmployeeType.MANAGER.getType()) {
 75             return new Manager();
 76         }
 77 
 78         throw new RuntimeException("unkown type!");
 79     }
 80 }
 81 
 82 /**
 83  * @title Employee
 84  * @description 员工基类
 85  * @author LZH
 86  * @date 2016-8-2 下午10:19:13
 87  */
 88 interface Employee {
 89 
 90     /**
 91      * 获取薪资
 92      * 
 93      * @return
 94      */
 95     public double getMonthSalary();
 96 }
 97 
 98 /**
 99  * @title Enginner
100  * @description 工程师
101  * @author LZH
102  * @date 2016-8-2 下午10:19:20
103  */
104 class Enginner implements Employee {
105 
106     @Override
107     public double getMonthSalary() {
108         return 10 * 1000;
109     }
110 
111 }
112 
113 /**
114  * @title Salesman
115  * @description 销售员
116  * @author LZH
117  * @date 2016-8-2 下午10:19:29
118  */
119 class Salesman implements Employee {
120 
121     @Override
122     public double getMonthSalary() {
123         return 20 * 1000;
124     }
125 
126 }
127 
128 /**
129  * @title Manager
130  * @description 经理
131  * @author LZH
132  * @date 2016-8-2 下午10:19:26
133  */
134 class Manager implements Employee {
135 
136     @Override
137     public double getMonthSalary() {
138         return 30 * 1000;
139     }
140 
141 }