HTTP Status 500 - Error instantiating servlet class com.Sansu.web.IndexServlet

type Exception report

message Error instantiating servlet class com.Sansu.web.IndexServlet

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Error instantiating servlet class com.Sansu.web.IndexServlet
	org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:213)
	org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:171)
	org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
	org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
	org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:394)

新引入文件时，提示找不到初始化类：

一、架包有问题：查看项目中build path里的架包是否都正确，不正确的加载正确的就行了

二、部署有问题：清除Tomcat服务器下的项目，重新加载。

我出现的问题是第一种，有一个架包报错了