Java | Use reflection to convert attribute values in enumeration Enum

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need

  During the development process, sometimes it is necessary to convert one field attribute value to another field attribute value in each enumeration class, such as performing front-end display according to the requirement of converting code to name. This article summarizes how to map enumeration attribute values ​​to each other simply and cleverly through reflection.

practice

enum class

package com.test.selfcoding;

/**
 * @Description TODO
 * @Author LiaoJy
 * @Date 2023/6/18
 */
public enum ColourEnum {
    
    

    /**
     * 红色
     */
    RED(1, "红色"),
    /**
     * 黄色
     */
    YELLOW(2, "黄色"),
    /**
     * 绿色
     */
    GREEN(3, "绿色");

    private Integer code;
    private String desc;

    ColourEnum(Integer code, String desc) {
    
    
        this.code = code;
        this.desc = desc;
    }

    public Integer getCode() {
    
    
        return code;
    }

    public String getDesc() {
    
    
        return desc;
    }

    public static String getDesc(Integer code) {
    
    
        for (ColourEnum c : ColourEnum.values()) {
    
    
            if (c.code.intValue() == code.intValue()) {
    
    
                return c.getDesc();
            }
        }
        return null;
    }

    public static Integer getCode(String desc) {
    
    
        for (ColourEnum c : ColourEnum.values()) {
    
    
            if (c.desc.equals(desc)) {
    
    
                return c.getCode();
            }
        }
        return null;
    }

    public static ColourEnum getEnum(Integer code) {
    
    
        if (code == null) {
    
    
            return null;
        }
        for (ColourEnum c : ColourEnum.values()) {
    
    
            if (c.code.intValue() == code.intValue()) {
    
    
                return c;
            }
        }
        return null;
    }

}

reflection test class

package com.test.selfcoding.service;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * @Description
 * @Author LiaoJy
 * @Date 2023/6/18
 */
public class EnumReflectServiceTest {
    
    

    public static void main(String[] args) throws NoSuchFieldException, ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
    
    
        String codeValue = "1";
        String descValue = "黄色";
        Class<Enum> clazz = (Class<Enum>) Class.forName("com.test.selfcoding.ColourEnum");
        if (Integer.class.equals(clazz.getDeclaredField("code").getType())) {
    
    
            Method method = clazz.getMethod("getDesc", Integer.class);
            String result = (String)  method.invoke(clazz, Integer.parseInt(codeValue));
            System.out.println("颜色描述：" + result);
        }

        if (String.class.equals(clazz.getDeclaredField("desc").getType())) {
    
    
            Method method = clazz.getMethod("getCode", String.class);
            Integer result = (Integer)  method.invoke(clazz, descValue);
            System.out.println("颜色编码：" + result);
        }
    }

}

operation result

颜色描述：红色
颜色编码：2