java嵌套对象转大map(扁平化)

        部分业务场景在传输数据时，需要的数据格式是扁平化的json格式，而在java对象中有时候为了解耦会做一些嵌套（即对象中包含对象，多层也是常有）。下面的代码可以提供该能力

处理单个对象：ObjectToMapUtil.nestedObj2Map

处理列表对象：ObjectToMapUtil.nestedObjList2ListMap

package cn.sto.station.twin.common.util;

import cn.sto.station.twin.common.util.json.JsonUtil;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;

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


@Slf4j
public class ObjectToMapUtil {

    private static final String SEPARATOR = "_";

    
    public static Map nestedObj2Map(Object object) {
        Map maps = JSON.parseObject(JSON.toJSONString(object), Map.class);
        Map result = new HashMap<>();
        maps.forEach((key, value) -> {
            common(maps, result, key, value, key);
        });
        return result;
    }

    
    public static  List> nestedObjList2ListMap(List objectList) {
        ArrayList> resultList = new ArrayList<>();
        for (T t : objectList) {
            resultList.add(nestedObj2Map(t));
        }
        return resultList;
    }

    public static Map nestedObj2Map(Map maps, String prefix) {
        Map result = new HashMap<>();
        String keyPrefix = prefix + SEPARATOR;
        maps.forEach((key, value) -> {
            String newKey = keyPrefix + key;
            common(maps, result, key, value, newKey);
        });
        return result;
    }

    public static void common(Map maps, Map result, String key, Object value, String newKey) {
        if (maps.get(key) != null && value instanceof JSONObject) {
            Map subMaps = (Map) maps.get(key);
            Map map = nestedObj2Map(subMaps, newKey);
            if (map != null && !map.isEmpty()) {
                result.putAll(map);
            }
        } else {
            result.put(newKey, maps.get(key));
        }
    }

    

}