Java中Bean转Map问题归纳总结

<dependency>
     <groupId>cn.hutool</groupId>
     <artifactId>hutool-all</artifactId>
     <version>5.8.10</version>
</dependency>
<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.6</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.72</version>
</dependency>
<dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.9.4</version>
</dependency>
<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib-nodep</artifactId>
    <version>3.2.12</version>
</dependency>
<dependency>
    <groupId>org.apache.dubbo</groupId>
    <artifactId>dubbo</artifactId>
    <version>3.0.9</version>
</dependency>

package com.zrj.tools.framework.entity;
import lombok.Data;
import java.util.Date;
/**
 * 类型转换对象
 *
 * @author zrj
 * @since 2023/1/8
 **/
@Data
public class MockObject {
    private Long id;
    private String aString;
    private Integer aInteger;
    private Long aLong;
    private Double aDouble;
    private Date aDate;
}

package com.zrj.tools.framework.utils;
import cn.hutool.core.bean.BeanUtil;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.google.gson.Gson;
import com.zrj.tools.framework.entity.MockObject;
import org.apache.commons.beanutils.BeanMap;
import org.apache.dubbo.common.utils.PojoUtils;
import java.util.Date;
import java.util.Map;
/**
 * Java Bean对象转Map，不同工具存在不同的问题
 * fastjson，gson转换类型不对
 * commonsbeanutils，cglib，转换的属性名称不对
 * dubbo，hutool转换类型与名称都没问题
 *
 * @author zrj
 * @since 2023/1/8
 **/
public class BeanToMapUtils {
    public static void main(String[] args) {
        MockObject mockObject = new MockObject();
        mockObject.setAString("jerry");
        mockObject.setAInteger(1);
        mockObject.setALong(2L);
        mockObject.setADate(new Date());
        mockObject.setADouble(3.4D);
        fastJsonBeanToMap(mockObject);
        commonsbeanutilsBeanToMap(mockObject);
        cglibBeanToMap(mockObject);
        hutoolBeanToMap(mockObject);
        gSonBeanToMap(mockObject);
        dubboBeanToMap(mockObject);
    }
    /**
     * dubboBeanToMap对象转Map
     * 类型与名称 都没问题
     */
    private static void dubboBeanToMap(MockObject mockObject) {
        Object beanMap = null;
        try {
            beanMap = PojoUtils.generalize(mockObject);
        } catch (Exception e) {
        }
        System.out.println("【cglibBeanToMap】 bean to map：" + beanMap);
        System.out.println(beanMap);
    }
    /**
     * hutool对象转Map
     * 类型与名称 都没问题
     */
    private static void hutoolBeanToMap(MockObject mockObject) {
        Map<String, Object> beanMap = BeanUtil.beanToMap(mockObject);
        System.out.println("【hutoolBeanToMap】 bean to map：" + beanMap);
    }
    /**
     * gson对象转Map，类型转换错误，通过debug可以看到
     * String 转换为 String
     * Integer 转换为 Double
     * Long 转换为 Double
     * Double 转换为 Double
     * Date 转换为 Date
     */
    private static void gSonBeanToMap(MockObject mockObject) {
        Gson gson = new Gson();
        Map<String, Object> beanMap = gson.fromJson(gson.toJson(mockObject), Map.class);
        //【gSonBeanToMap】 bean to map：{aString=jerry, aInteger=1.0, aLong=2.0, aDouble=3.4, aDate=Jan 8, 2023 4:22:17 PM}
        System.out.println("【gSonBeanToMap】 bean to map：" + beanMap);
    }
    /**
     * cglib对象转Map
     * 存在和 commonsbeanutils 一样的问题，虽然类型没问题，但是属性名还是不对。
     * 名称aDouble 转换为 ADouble，等等
     */
    private static void cglibBeanToMap(MockObject mockObject) {
        net.sf.cglib.beans.BeanMap beanMap = net.sf.cglib.beans.BeanMap.create(mockObject);
        System.out.println("【cglibBeanToMap】 bean to map：" + beanMap);
        //ADouble=3.4，aDouble=null
        System.out.println(beanMap.get("aDouble"));
        System.out.println(beanMap.get("ADouble"));
    }
    /**
     * commonsbeanutils对象转Map
     * 存在和 cglib 一样的问题，虽然类型没问题，但是属性名还是不对。
     * 名称aDouble 转换为 ADouble，等等
     */
    private static void commonsbeanutilsBeanToMap(MockObject mockObject) {
        BeanMap beanMap = new BeanMap(mockObject);
        //【commonsbeanutils】 bean to map：BeanMap<MockObject(id=null, aString=jerry, aInteger=1, aLong=2, aDouble=3.4, aDate=Sun Jan 08 15:29:25 CST 2023)>
        System.out.println("【commonsbeanutils】 bean to map：" + beanMap);
        //ADouble=3.4，aDouble=null
        System.out.println(beanMap.get("aDouble"));
        System.out.println(beanMap.get("ADouble"));
    }
    /**
     * fastjson对象转Map，类型转换错误，通过debug可以看到
     * String 转换为 String
     * Integer 转换为 Integer
     * Long 转换为 Integer
     * Double 转换为 BigDecimal
     * Date 转换为 Long
     */
    private static void fastJsonBeanToMap(MockObject mockObject) {
        String json = JSON.toJSONString(mockObject);
        Map<String, Object> map = JSON.parseObject(json, new TypeReference<Map<String, Object>>() {
        });
        //【fastjson】 bean to map：{aString=jerry, aLong=2, aDate=1673162965198, aDouble=3.4, aInteger=1}
        System.out.println("【fastjson】 bean to map：" + map);
    }
}

try {
    PubOrgan organ = new PubOrgan();
    Map<String,String> map = new HashMap();
    map.put("organId", "1");
    map.put("organName", "www.4spaces.org");
    BeanUtils.populate(organ, map);
} catch (IllegalAccessException e) {
    e.printStackTrace();
} catch (InvocationTargetException e) {
    e.printStackTrace();
}