Tomcat5.0 连接池 ClassNotFoundException:com.mysql.jdbc.Driver

目前正在初学连接池 发生了个奇怪的问题 使用正常连接jdbc没有问题 但是用连接池就出现ClassNotFoundException:com.mysql.jdbc.Driver 错误
我jar包已经放入工程的lib目录内 请朋友们帮忙

我的部分原文:
java代码中:
try {

// Class.forName("com.mysql.jdbc.Driver");
// con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");

InitialContext ic=new InitialContext();
DataSource ds=(DataSource)ic.lookup("java:comp/env/jdbc/dateTest");

con=ds.getConnection();
st=con.createStatement();
rs=st.executeQuery("SELECT * FROM menu");
while(rs.next()){
Item i=new Item(rs.getInt(1),rs.getString(2));
al.add(i);
}
} catch (Exception e) {
e.printStackTrace();
}
结果st=con.createStatement();出错

我的工程名是:dateSource
C:\Program Files\Apache Software Foundation\Tomcat 5.0\conf\Catalina\localhost\dateSource.xml:

<?xml version='1.0' encoding='utf-8'?>
<Context docBase="C:\Program Files\Apache Software Foundation\Tomcat 5.0\webapps\dateSource" path="/dateSource" workDir="work\Catalina\localhost\dateSource">
<Resource name="jdbc/dateTest" type="javax.sql.DataSource"/>

<ResourceParams name="jdbc/dateTest">
<parameter>
<name>maxWait</name>
<value>5000</value>
</parameter>
<parameter>
<name>maxActive</name>
<value>10</value>
</parameter>
<parameter>
<name>password</name>
<value>root</value>
</parameter>
<parameter>
<name>url</name>
<value>jdbc:mysql://localhost:3306/test</value>
</parameter>
<parameter>
<name>driverClassName</name>
<value>com.mysql.jdbc.Driver</value>
</parameter>
<parameter>
<name>maxIdle</name>
<value>2</value>
</parameter>
<parameter>
<name>username</name>
<value>root</value>
</parameter>
</ResourceParams>
</Context>

工程的web.xml中:
<resource-ref>
<res-ref-name>jdbc/dateTest</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>

错误信息为:
rg.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver'
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:766)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
at com.wish.dao.ItemDAO.getAll(ItemDAO.java:35)
at com.wish.contorlly.ItemServlet.doGet(ItemServlet.java:30)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:854)
at org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:721)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:760)
... 29 more

我在强调一下:工程的lib目录下有mysql-connector-java-5.0.3-bin.jar
而且在
C:\Program Files\Apache Software Foundation\Tomcat 5.0\webapps\dateSource\WEB-INF\lib也有
mysql-connector-java-5.0.3-bin.jar

为什么还是ClassNotFoundException错误呢??

因为是新人暂无分数 所以请各位现帮忙 谢谢了