JAVA拷贝Map和List中的值到对象

1、还是使用我们的老朋友hutool

       
            cn.hutool
            hutool-all
            5.8.0
        

2、实体类

package com.lezu.springboot.common.dto;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.math.BigDecimal;
import java.util.List;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
@Accessors(chain = true)
public class UserDto {
    private String name;

    private Integer qty;

    private BigDecimal money;

    private List role;

}

3、复制map到对象

package com.lezu.springboot.test.lian;

import cn.hutool.core.bean.BeanUtil;
import com.alibaba.fastjson.JSON;
import com.lezu.springboot.common.dto.UserDto;

import java.util.HashMap;
import java.util.Map;

public class Test2 {
    public static void main(String[] args) {
        UserDto userDto = new UserDto();
        Map map = new HashMap<>();
        map.put("name", "张三");
        map.put("qty", "111");
        map.put("money", "10000");
        BeanUtil.copyProperties(map, userDto);
        System.out.println(userDto);
        System.out.println(JSON.toJSONString(userDto));


    }

Map里面放List 

package com.lezu.springboot.test.lian;

import cn.hutool.core.bean.BeanUtil;
import com.alibaba.fastjson.JSON;
import com.lezu.springboot.common.dto.UserDto;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Test2 {
    public static void main(String[] args) {
        UserDto userDto = new UserDto();
        Map map = new HashMap<>();
        List role = new ArrayList<>();
        role.add("100");
        role.add("200");
        role.add("300");
        map.put("role", role);
        BeanUtil.copyProperties(map, userDto);
        System.out.println(userDto);
        System.out.println(JSON.toJSONString(userDto));
    }
}

 3、复制List到对象

package com.lezu.springboot.common.dto.in;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.math.BigDecimal;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
@Accessors(chain = true)
public class InUserDto {
    private String name;

    private Integer qty;

    private BigDecimal money;

}

List复制

package com.lezu.springboot.test.lian;

import cn.hutool.core.bean.BeanUtil;
import com.alibaba.fastjson.JSON;
import com.lezu.springboot.common.dto.UserDto;
import com.lezu.springboot.common.dto.in.InUserDto;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

public class Test2 {
    public static void main(String[] args) {

        List list = new ArrayList<>();
        list.add(new InUserDto("张三", 111, new BigDecimal("10000")));
        list.add(new InUserDto("李四", 222, new BigDecimal("10000")));
        list.add(new InUserDto("小王", 333, new BigDecimal("10000")));

        List userDtoList = BeanUtil.copyToList(list, UserDto.class);
        System.out.println(userDtoList);
        System.out.println(JSON.toJSONString(userDtoList));


    }


}

 

4、我们再试试使用org.springframework.beans.BeanUtils的包复制试试

复制Map

Map中放List进行复制

复制List

package com.lezu.springboot.test.lian;

import com.alibaba.fastjson.JSON;
import com.lezu.springboot.common.dto.UserDto;
import com.lezu.springboot.common.dto.in.InUserDto;
import org.springframework.beans.BeanUtils;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

public class Test2 {
    public static void main(String[] args) {
        List userDtoList = new ArrayList<>();
        List list = new ArrayList<>();
        list.add(new InUserDto("张三", 111, new BigDecimal("10000")));
        list.add(new InUserDto("李四", 222, new BigDecimal("10000")));
        list.add(new InUserDto("小王", 333, new BigDecimal("10000")));
        BeanUtils.copyProperties(list, userDtoList);
        System.out.println(userDtoList);
        System.out.println(JSON.toJSONString(userDtoList));
    }
}

 

很显然使用org.springframework.beans.BeanUtils复制Map和List是不行的

 PS：

• 面对不同的业务场景可以选择使用不同包中的方法 
• 对象copy对象建议最好还是用org.springframework.beans.BeanUtils
• 可以参考:实体类中Date转时间戳(Long) BeanUtils的正确使用