failed to lazily initialize a collection of role: no session or session was clos

 one-to-many  也有 lazy属性 注意位置

        <set name="userRoles" inverse="true" lazy="false">
            <key>
                <column name="user_id" not-null="true" />
            </key>
            <one-to-many class="org.zpgl.model.UserRole" />
        </set>