通过反射获取常量值

Posted 2020-09-21 格物致知

一：通过反射获取常量值，项目中有个需求需要将请求信息封装到javaBean中

但是请求信息比较特殊，需要通过编码去获取，而且编码是定义在接口类中的常量，所以为了方便

特别把这块功能封装起来

1：定义的常量

 1 /**
 2  * 
 3  */
 4 package com.hlcui.entity;
 5 
 6 /**
 7  * @author Administrator
 8  *
 9  */
10 public interface ConstantsUtil {
11     
12     public static interface TeamFundMgr{
13         public static final int id = 111;
14         public static final String name = "李白";
15         public static final double salary = 15000.000;
16     }
17     
18 }

2：javaBean类

 1 /**
 2  * 
 3  */
 4 package com.hlcui.entity;
 5 
 6 /**
 7  * @author Administrator
 8  *
 9  */
10 public class Person {
11     
12     private int id;
13     
14     private String name;
15     
16     private double salary;
17     
18     private String mgr;
19     
20     public int getId() {
21         return id;
22     }
23 
24     public void setId(int id) {
25         this.id = id;
26     }
27 
28     public double getSalary() {
29         return salary;
30     }
31 
32     public void setSalary(double salary) {
33         this.salary = salary;
34     }
35 
36     public String getMgr() {
37         return mgr;
38     }
39 
40     public void setMgr(String mgr) {
41         this.mgr = mgr;
42     }
43 
44     public String getName() {
45         return name;
46     }
47 
48 
49     public void setName(String name) {
50         this.name = name;
51     }
52 
53     @Override
54     public String toString() {
55         return "Person [id=" + id + ", name=" + name + ", salary=" + salary + ", mgr=" + mgr + "]";
56     }
57     
58 }

3：转换以及测试方法

 1 /**
 2  * 
 3  */
 4 package com.hlcui.test;
 5 
 6 import java.beans.BeanInfo;
 7 import java.beans.Introspector;
 8 import java.beans.PropertyDescriptor;
 9 import java.lang.reflect.Field;
10 import java.lang.reflect.Method;
11 
12 import com.hlcui.entity.ConstantsUtil;
13 import com.hlcui.entity.Person;
14 
15 /**
16  * @author Administrator
17  *
18  */
19 public class TestOperateConstant {
20     
21     private static final String EXCLUDE_FIELD = "class";
22     
23     public static void main(String[] args) throws Exception {
24         Person person = toBean(new Person());
25         System.out.println(person);
26     }
27     
28     public static <T> T toBean(T t){
29         Class<?> clazz = t.getClass();
30         try {
31             BeanInfo beanInfo = Introspector.getBeanInfo(clazz);
32             PropertyDescriptor[] props = beanInfo.getPropertyDescriptors();
33             for(PropertyDescriptor property:props){
34                 String field = property.getName();
35                 if(EXCLUDE_FIELD.equals(field)){
36                     continue;
37                 }
38                 Method method = property.getWriteMethod();
39                 method.invoke(t,getValue(field,ConstantsUtil.TeamFundMgr.class));
40             }
41         } catch (Exception e) {
42             e.printStackTrace();
43         }
44         return t;
45     }
46     
47     public static Object getValue(String fieldName,Class<?> clazz)throws Exception{
48         Field[] fields = clazz.getDeclaredFields();
49         for(Field field:fields){
50             String name = field.getName();
51             if(fieldName.equals(name)){
52                 return field.get(clazz);
53             }
54         }
55         return null;
56     }
57 }

4：运行结果

1 Person [id=111, name=李白, salary=15000.0, mgr=null]