serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no proper

今天在做用json异步提交按关键字查询数据的时候总是出现 No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties discovered异常，一开始总是以为是List集合转换成json数据的时候转换不成功，经过百度查询资料已经结合hibernate的文档，终于解决了问题。

异常

java.lang.IllegalArgumentException: com.fasterxml.jackson.databind.JsonMappingException: No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.SerializationFeature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: java.util.ArrayList[0]->org.iep.model.hibernate.Menu["parent_menu"]->org.iep.model.hibernate.Menu_$$_jvst62a_2["handler"])

原来的Menu.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2015-5-10 22:16:21 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
<class name="org.iep.model.hibernate.Menu" table="t_base_menu">
<id name="id" type="java.lang.Integer">
<column name="ID" />
<generator class="assigned" />
</id>
<property name="name" type="java.lang.String">
<column name="NAME" />
</property>
<property name="url" type="java.lang.String">
<column name="URL" />
</property>
<property name="ico" type="java.lang.String">
<column name="ICO" />
</property>
<property name="status" type="java.lang.Integer">
<column name="STATUS" />
</property>
<property name="parent_id" type="java.lang.Integer">
<column name="PARENT_ID" />
</property>
<many-to-one name="parent_menu" column="parent_id" class="org.iep.model.hibernate.Menu" update="false" insert="false"
/>
</class>
</hibernate-mapping>

解决办法只要在

<many-to-one name="parent_menu" column="parent_id" class="org.iep.model.hibernate.Menu" update="false" insert="false"
/>

中添加

lazy="false"

下面是网上面的解释

出现这种异常的本质原因是有点诡异，hibernate在获取一个Entity的时候，第一步获取到是Entity的Proxy. 如果仅仅在获取到Proxy以后Session就关闭的话，就会出现这个异常。在Hibernate3.0中，Entity的Proxy与真实实体之间默认是lazy loading的，如果在一个transaction仅仅获取了一下Entity的Proxy，然后transaction就commit， 这个时候也会出现上述异常。