请教SAXParseException问题

系统是运行在Tomcat5上,基于Struts开发的,用到JFreeChart。可总是给出下面的警告,在网上找了,有的说导入xercesImpl.jar,xml-apis.jar就没事,有的说导入jcommon.jar.可都问能解决问题。望高手指点一下。叩谢!
........
ParserUtils: warning org.xml.sax.SAXParseException: No base URI; hope URI is abs
olute: http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd
ParserUtils: warning org.xml.sax.SAXParseException: No base URI; hope this SYSTE
M id is absolute: http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd
ParserUtils: warning org.xml.sax.SAXParseException: URI was not reported to pars
er for entity [dtd]
ParserUtils: warning org.xml.sax.SAXParseException: missing system ID, using htt
p://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd
ParserUtils: warning org.xml.sax.SAXParseException: URI was not reported to pars
er for entity [document]
ParserUtils: warning org.xml.sax.SAXParseException: No base URI; hope URI is abs
olute: http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd
........

不好意思,上面是未能解决问题。

你将你的机器联网后试验看看可否。可能是一些支持包版本太老了一些。