java报错：Type handler was null on parameter mapping for property ‘*‘,jdbcType (null) combination.

实体类字段为JSON类型时，必须使用标签进行判定以排除其为null的可能性，否则会报下面的找不到为null时的指定。

Cause: java.lang.IllegalStateException: Type handler was null on parameter mapping for property 'urlParams'. It was either not specified and/or could not be found for the javaType (com.alibaba.fastjson.JSONObject) : jdbcType (null) combination.

解决方法：在java对应的实体类添加对应的字段，重点是加上(typeHandler = JacksonTypeHandler.class)这个注解

来源地址：https://blog.csdn.net/weixin_44729970/article/details/129144918