Gson key “_“ 驼峰命名

import cn.hutool.core.date.DatePattern;
import com.google.common.reflect.TypeToken;
import com.google.gson.*;
import org.apache.commons.lang3.StringUtils;

import javax.validation.constraints.NotNull;
import java.lang.reflect.Type;
import java.util.*;

public class GsonUtil {

    private static Gson gson = null;

    static {

        gson = new GsonBuilder().setDateFormat(DatePattern.NORM_DATETIME_PATTERN)
                .registerTypeAdapter(new TypeToken<HashMap<String, Object>>() {
                }.getType(), (JsonDeserializer<HashMap<String, Object>>) (json, typeOfT, context) -> {
                    HashMap<String, Object> hashMap = new HashMap<>();
                    JsonObject jsonObject = json.getAsJsonObject();
                    Set<Map.Entry<String, JsonElement>> entrySet = jsonObject.entrySet();
                    for (Map.Entry<String, JsonElement> entry : entrySet) {
                        Object ot = entry.getValue();
                        if (ot instanceof JsonPrimitive) {
                            hashMap.put(entry.getKey(), ((JsonPrimitive) ot).getAsString());
                        } else {
                            hashMap.put(entry.getKey(), ot);
                        }
                    }
                    return hashMap;
                }).create();


    }


    public GsonUtil() {
        throw new InstantiationError("Must not instantiate this class");
    }

    /**
     * 将Obj转换成Json
     *
     * @param obj
     * @return
     */
    public static @NotNull String ToJson(Object obj) {
        return gson.toJson(obj);
    }


    public static JsonElement strToJsonElement(String str) {