“The string "--" is not permitted ...”的错误，解决方法

————>错误现象：

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" java.lang.ExceptionInInitializerError
at test.HibernateTest.saveDE(HibernateTest.java:30)
at test.HibernateTest.main(HibernateTest.java:18)
Caused by: org.hibernate.InvalidMappingException: Could not parse mapping document from resource com/xx/domain/Depart.hbm.xml
...........
Caused by: org.dom4j.DocumentException: Error on line 15 of document : The string "--" is not permitted within comments. Nested exception: The string "--" is not permitted within comments.
at org.dom4j.io.SAXReader.read(SAXReader.java:482)
...........

-------------->原因及解决方法

原因是我在Hibernate的hbm.xml中加入了如下注释：

<!----------- depart通过depart_id查找到employee ------------->
<!-------------
<set name="ems">
<key column="depart_id"/>
<one-to-many class="Employee" />
</set>
----------------->

加了几个“---”看着是显眼（jsp中经常这么干），就报了这么个错，把多余的横线删除就ok了！网上说和解释中的字数个数有关，好像不是吧(⊙o⊙)。