No serializer found for class cn.hutool.json.JSONNull and no properties discovered to create

No serializer found for class cn.hutool.json.JSONNull and no properties discovered to create

问题记录：

调用第三方接口进行json解析时出现了：No serializer found for class cn.hutool.json.JSONNull and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: istmon.api.vo.Result[“data”]->cn.hutool.json.JSONObject[“data”]->cn.hutool.json.JSONObject[“vehicle_list”]->cn.hutool.json.JSONArray[0]->cn.hutool.json.JSONObject[“vehicle_std_item”]->cn.hutool.json.JSONArray[0]->cn.hutool.json.JSONObject[“desc”])

http-nio-9003-exec-5           20230802 20:20:40.025 ERROR traceId=[] org.ContainerBase.[Tomcat].[localhost].[/logistics].[dispatcherServlet] - Servlet.service() for servlet [dispatcherServlet] in context with path [/logistics] threw exception [Request processing failed; nested exception is org.verter.HttpMessageConversionException: Type definition error: [simple type, class cn.hutool.json.JSONNull]; nested exception is com.fasterxml.InvalidDefinitionException: No serializer found for class cn.hutool.json.JSONNull and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: istmon.api.vo.Result["data"]->cn.hutool.json.JSONObject["data"]->cn.hutool.json.JSONObject["vehicle_list"]->cn.hutool.json.JSONArray[0]->cn.hutool.json.JSONObject["vehicle_std_item"]->cn.hutool.json.JSONArray[0]->cn.hutool.json.JSONObject["desc"])] with root cause
com.fasterxml.InvalidDefinitionException: No serializer found for class cn.hutool.json.JSONNull and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: istmon.api.vo.Result["data"]->cn.hutool.json.JSONObject["data"]->cn.hutool.json.JSONObject["vehicle_list"]->cn.hutool.json.JSONArray[0]->cn.hutool.json.JSONObject["vehicle_std_item"]->cn.hutool.json.JSONArray[0]->cn.hutool.json.JSONObject["desc"])at com.fasterxml.InvalidDefinitionException.from(InvalidDefinitionException.java:77)at com.fasterxml.jackson.portBadDefinition(SerializerProvider.java:1277)at com.fasterxml.jackson.portBadDefinition(DatabindContext.java:400)at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:71)at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.serialize(UnknownSerializer.java:33)at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:726)at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeWithoutTypeInfo(MapSerializer.java:681)at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:637)at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:33)at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:119)at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serialize(IndexedListSerializer.java:79)

我使用的代码是：

 JSONObject jsonObject = JSONUtil.parseObj(post);

解释：

Hutool会使用JSONNull来表示空值，而SpringBoot默认使用的序列化是Jackson，在接口调用过程中使用了Map，直接传入了Hutool的JSONObject，而该Map存在空值，所以存在JSONNull，最终导致错误。

修改：

使用 com.alibaba.fastjson 来解析：

com.alibaba.fastjson.JSONObject jsonObject = com.alibaba.fastjson.JSONObject.parseObject(gpString);