Cannot serialize object from mybatis and it has a field lazy-loaded

[formingform]

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Describe the bug

Jackson 2.13.5 Spring Boot 2.17.x Mybatis 3.5.x JDK 17

Here is my Mybatis map.xml

<resultMap id="BaseResultMap" type="User">
	<id property="id" column="id" jdbcType="INTEGER"/>
	<result property="name" column="name" jdbcType="VARCHAR"/>
	<collection property="bookNames"
				ofType="String"
				column="name"
				jdbcType="VARCHAR"
				select="BookMapper.listBookNamesByOwner" fetchType="lazy"/>
</resultMap>

......

<select id="selectByPrimaryKey" parameterType="java.lang.Long" resultMap="BaseResultMap">
	select
	<include refid="Base_Column_List" />
	from user
	where id = #{id,jdbcType=INTEGER}
</select>

jackson cannot serialize the result of selectByPrimaryKey because of fetchType="lazy", error message like this:

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.apache.ibatis.executor.loader.javassist.JavassistProxyFactory$EnhancedResultObjectProxyImpl and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)

and if set fetchType=“eager" or remove fetchType="lazy", Jackson works fine.

Version Information

Jackson verison: 2.13.5

Reproduction

[yawkat]

Not sure what you want us to do, here

[pjfanning]

We do not generally accept issues where many libs are used. Reproducible cases should generally use only Jackson libs. I believe this should be reported to the myBatis community or on stackoverflow.com.

[cowtowncoder]

Yes, "exotic" types by 3rd party libraries/frameworks tend to require special supported, provided often as Jackson datatype modules: for Hibernate, there is https://github.com/FasterXML/jackson-datatype-hibernate/ .

Such libraries would ideally be created and maintained by library/framework maintainers. But we sometimes accept contributions if users want to write implementations. That requires someone with myBatis and Jackson knowledge.

In this case it is very likely that such contribution (PR) would be needed. Or possibly someone sharing way they have used Jackson configuration and/or custom (de)serializers.

[cowtowncoder]

Nothing we can do in jackson-databind: would require dedicated datatype module most likely. Will close: anyone can work on implementing and contributed such module; if so, can file an issue somewhere else; f.ex start a Discussion at

https://github.com/FasterXML/jackson/discussions