tomcat5.0+eclipse+mysql5访问报错，郁闷中，很简单...

server.xml
<ResourceParams name="jdbc/ExcelReport">
<parameter>
<name>driverClassName</name>
<value>com.mysql.jdbc.Driver</value>
</parameter>
<parameter>
<name>url</name>
<value>jdbc:mysql://localhost:3306/excel</value>
</parameter>
<parameter>
   <name>username</name>
   <value>root</value>
</parameter>
<parameter>
   <name>password</name>
   <value>gary</value>
  
</parameter>
<parameter>
   <name>maxActive</name>
   <value>100</value>
</parameter>
<parameter>
   <name>maxIdle</name>
   <value>20</value>
</parameter>
<parameter>
   <name>maxWait</name>
   <value>-1</value>
</parameter>
  </ResourceParams>
web.xml<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE web-app
  PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
  "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd"><web-app>
<display-name>Struts Taglib Exercises</display-name>  <!-- Action Servlet Configuration -->
  <servlet>
    <servlet-name>action</servlet-name>
    <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
    
    <init-param>
      <param-name>config</param-name>
      <param-value>/WEB-INF/struts-config.xml</param-value>
    </init-param>
    <init-param>
      <param-name>debug</param-name>
      <param-value>2</param-value>
    </init-param>
    <init-param>
      <param-name>detail</param-name>
      <param-value>2</param-value>
    </init-param>
    <load-on-startup>2</load-on-startup>
  </servlet>
  
  <servlet>
    <servlet-name>report</servlet-name>
    <servlet-class>net.excel.report.ExcelReportServlet</servlet-class>
    
    <init-param>
      <param-name>TempletFilePath</param-name>
      <param-value>/WEB-INF/classes/ReportConfig</param-value>
    </init-param>
    <init-param>
      <param-name>JNDI</param-name>
      <param-value>java:/comp/env/jdbc/ExcelReport</param-value>
    </init-param>
  </servlet>  <!-- Action Servlet Mapping -->
  <servlet-mapping>
    <servlet-name>action</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
    <servlet-name>report</servlet-name>
    <url-pattern>/report</url-pattern>
  </servlet-mapping>  <!-- The Welcome File List -->
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>
  <!-- Struts Tag Library Descriptors -->
  <taglib>
    <taglib-uri>/tags/struts-bean</taglib-uri>
    <taglib-location>/WEB-INF/struts-bean.tld</taglib-location>
  </taglib>  <taglib>
    <taglib-uri>/tags/struts-html</taglib-uri>
    <taglib-location>/WEB-INF/struts-html.tld</taglib-location>
  </taglib>  <taglib>
    <taglib-uri>/tags/struts-logic</taglib-uri>
    <taglib-location>/WEB-INF/struts-logic.tld</taglib-location>
  </taglib>
<resource-ref>
    <description>DB Connection</description>
    <res-ref-name>jdbc/ExcelReport </res-ref-name>
    <res-type>javax.sql.DataSource </res-type>
    <res-auth>Container </res-auth>
   </resource-ref>

</web-app>
报错：type Exception reportmessagedescription The server encountered an internal error () that prevented it from fulfilling this request.exceptionjavax.servlet.ServletException: Cannot create JDBC driver of class '' for connect URL 'null'
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:825)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:758)
org.apache.jsp.test_jsp._jspService(test_jsp.java:80)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)root causeorg.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'
org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:780)
org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
org.apache.jsp.test_jsp._jspService(test_jsp.java:58)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.