Java Mybatis懶加載報錯末尾顯示_$$_jvst12a_0["handler"])的解決方案

異常信息

Type definition error: [simple type, class org.apache.ibatis.executor.loader.javassist.JavassistProxyFactoryEnhancedResultObjectProxyImpl];nestedexceptioniscom.fasterxml.jackson.databind.exc.InvalidDefinitionException:Noserializerfoundforclassorg.apache.ibatis.executor.loader.javassist.JavassistProxyFactoryEnhancedResultObjectProxyImpl]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.apache.ibatis.executor.loader.javassist.JavassistProxyFactoryEnhancedResultObjectProxyImpl];nestedexceptioniscom.fasterxml.jackson.databind.exc.InvalidDefinitionException:Noserializerfoundforclassorg.apache.ibatis.executor.loader.javassist.JavassistProxyFactoryEnhancedResultObjectProxyImpl and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: com.ruoyi.framework.web.page.TableDataInfo[“rows”]->com.github.pagehelper.Page[0]->com.ruoyi.project.system.student.domain.ZStudent_$$_jvst12a_0[“handler”])

解決方法

1. 關閉該查詢的懶加載 fetchType="eager"
   下面的兩種方法我也試過，好像並沒有什么作用，在進行序列化的時候就會出現問題比如說BackstageRole會變成Backstage_$$_jvst12a_0這種代理對象（非原始對象）。

    <resultMap id="RoleMap" type="com.hyper.netman.entity.business.BackstageRole">
        <result column="id" property="id"/>
        <result column="role_name" property="roleName"/>
        <result column="role_desc" property="roleDesc"/>
        <result column="create_time" property="createTime"/>
        <result column="modify_time" property="modifyTime"/>
        <!--需要關閉懶加載，不然對象不是原來的對象-->
        <collection property="resources" column="id" javaType="list" fetchType="eager" select="getRolesMenus"/>
    </resultMap>

2. 返回的類加上注解（即實體類）

@JsonIgnoreProperties(value = { "handler" })
public class BackstageRole{}

3. 配置json轉換器屬性 SerializationFeature.FAIL_ON_EMPTY_BEANS為false

spring:
  jackson:
    serialization:
      FAIL_ON_EMPTY_BEANS: false