ssh框架整合：使用SchemExport出现异常

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Warning: Caught exception attempting to use SAX to load a SAX XMLReader
java.lang.ClassNotFoundException: org/apache/xerces/parsers/SAXParser
Warning: Exception was: java.lang.ClassNotFoundException: org/apache/xerces/parsers/SAXParser
Warning: I will print the stack trace then carry on using the default SAX parser
at org.xml.sax.helpers.XMLReaderFactory.loadClass(Unknown Source)
at org.xml.sax.helpers.XMLReaderFactory.createXMLReader(Unknown Source)
at org.dom4j.io.SAXHelper.createXMLReader(SAXHelper.java:83)
at org.dom4j.io.SAXReader.createXMLReader(SAXReader.java:894)
at org.dom4j.io.SAXReader.getXMLReader(SAXReader.java:715)
at org.dom4j.io.SAXReader.read(SAXReader.java:435)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1532)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1476)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1462)
at org.eSale.util.ExportDB.main(ExportDB.java:9)
Exception in thread "main" org.hibernate.HibernateException: Could not parse configuration: /hibernate.cfg.xml
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1542)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1476)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1462)
at org.eSale.util.ExportDB.main(ExportDB.java:9)
Caused by: org.dom4j.DocumentException: SAX2 driver class org.apache.xerces.parsers.SAXParser not found Nested exception: SAX2 driver class org.apache.xerces.parsers.SAXParser not found
at org.dom4j.io.SAXReader.read(SAXReader.java:484)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1532)
... 3 more
使用SchemExport的时候报这个错是什么意思啊，dom4j.jar包确实加过了，但就是报这个，这是什么情况？