exception setting property value with CGLIB

配置文件<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 2.0//EN" 
    "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd"><hibernate-mapping
>
    <class
        name="com.alysoft.ct.model.Department"
        table="department"
        dynamic-update="false"
        dynamic-insert="false"
        select-before-update="false"
    >        <id
            name="id"
            column="id"
            type="java.lang.Long"
            length="11"
            unsaved-value="null"
        >
            <generator class="native">
              <!--  
                  To add non XDoclet generator parameters, create a file named 
                  hibernate-generator-params-Department.xml 
                  containing the additional parameters and place it in your merge dir. 
              --> 
            </generator>
        </id>        <version
            name="version"
            type="java.lang.Long"
            column="version"
            access="property"
            unsaved-value="undefined"
        />        <property
            name="name"
            type="java.lang.String"
            update="true"
            insert="true"
            access="property"
            column="name"
            length="63"
        />        <property
            name="description"
            type="java.lang.String"
            update="true"
            insert="true"
            access="property"
            column="description"
            length="255"
        />        <many-to-one
            name="parentDepartment"
            class="com.alysoft.ct.model.Department"
            cascade="save-update"
            outer-join="auto"
            update="true"
            insert="true"
            access="property"
            column="super_dept_id"
        />        <many-to-one
            name="manager"
            class="com.alysoft.ct.model.User"
            cascade="save-update"
            outer-join="auto"
            update="true"
            insert="true"
            access="property"
            column="manager_id"
        />        <set
            name="subDepartments"
            table="department"
            lazy="true"
            inverse="true"
            cascade="save-update"
            sort="unsorted"
        >              <key
                  column="super_dept_id"
              >
              </key>              <one-to-many
                  class="com.alysoft.ct.model.Department"
              />        </set>        <set
            name="subUsers"
            table="user"
            lazy="true"
            inverse="true"
            cascade="save-update"
            sort="unsorted"
        >              <key
                  column="dept_id"
              >
              </key>              <one-to-many
                  class="com.alysoft.ct.model.User"
              />        </set>        <!--
            To add non XDoclet property mappings, create a file named
                hibernate-properties-Department.xml
            containing the additional properties and place it in your merge dir.
        -->    </class></hibernate-mapping>