tomcat 连接 mysql 报错 ，大哥们帮帮忙

greendays

tomcat 安装和配置变量都正确， JDK 环境变量配置也正确。下面是错误代码：
HTTP Status 500 -

type Exception report

message

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

exception

org.apache.jasper.JasperException: Exception in JSP: /Index.jsp:14

11: %>
12: <%
13: NewsDAO nd=new NewsDAO();
14: List<News> nList=nd.getNewsList();
15: int newsSize=11;
16: if(nList.size()<=newsSize){
17:         newsSize=nList.size();


Stacktrace:
        org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:451)
        org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:355)
        org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
        org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

root cause

javax.servlet.ServletException: com/youdo/isdi/db/DB
        org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:841)
        org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:774)
        org.apache.jsp.Index_jsp._jspService(Index_jsp.java:779)
        org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:9
        javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
        org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
        org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
        org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

root cause

java.lang.NoClassDefFoundError: com/youdo/isdi/db/DB
        com.youdo.isdi.news.NewsDAO.getNewsList(NewsDAO.java:54)
        org.apache.jsp.Index_jsp._jspService(Index_jsp.java:72)
        org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:9
        javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
        org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
        org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
        org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:729)

note The full stack trace of the root cause is available in the Apache Tomcat/5.5.27 logs.

rover12421

没用过 tomcat 帮不了你

greendays

仍然谢谢兄弟！ 还在测试  估计很快就会解决。

ziggler

java.lang.NoClassDefFoundError: com/youdo/isdi/db/DB 估计是CLASSPATH的问题。