net.sf.hibernate.MappingException: could not instantiate id generator
<?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="jb_hibernate.Message" table="Message">
<id name="id" column="MESSAGE_ID">
<generator class="sequence">
<param name="sequence">MESSAGE_SEQ</param>
</generator>
</id>
<property name="text" type="string">
<column name="TEXT" length="100" not-null="true"/>
</property>
<many-to-one name="nextMessage" cascade="all" column="NEXT_MESSAGE_ID"/>
</class>
</hibernate-mapping>
有什么问题呀？
------解决方法--------------------------------------------------------
数据库中有没有MESSAGE_SEQ了啊？
