tomcat网页访问数据库时报错:java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver

我的环境变量设置如下:
Path=D:\app\hgfgoodcreate\product\11.2.0\dbhome_1\bin;C:\Windows\system32;C:\Win
dows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Pro
gram Files\Java\jdk1.7.0_07\bin;C:\Program Files\nodejs\;C:\Users\hgfgoodcreate\
AppData\Roaming\npm

CLASS_PATH=.;C:\Program Files\Java;C:\Program Files\Java\jdk1.7.0_07\lib\tools.j
ar;C:\Program Files\Java\ojdbc6.jar;D:\app\hgfgoodcreate\product\11.2.0\dbhome_1
\jdbc\lib;D:\app\hgfgoodcreate\product\11.2.0\dbhome_1\jdbc\lib\ojdbc6.jar;

报错:
java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:186)
at com.hgf.guestbook.addMessageServlet.doPost(addMessageServlet.java:52)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)

...