项目运行时出现HTTP Status 500 - 源文件在其他机器上好用。新装一台就出现错误，求教大侠
数据库是oracle 9 。装在服务器上的。本机装了一个简易版的oracle 客户端。链接正常。
但放到tomcat 中运行，出现如下错误：：不知什么原因。向各位大侠求解。
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: javax.servlet.ServletException: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:491)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:401)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
javax.servlet.ServletException: java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:862)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:791)
org.apache.jsp.ems.index_jsp._jspService(index_jsp.java:479)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1645)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1491)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:128)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:66)
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:169)
org.apache.jsp.ems.index_jsp._jspService(index_jsp.java:153)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.29 logs.
------解决方案--------------------------------------------------------
没有加载数据库驱动吧。。。