j2ee 加载oracle.jdbc.driver.OracleDriver 报错已经导入包了,该如何处理

j2ee 加载oracle.jdbc.driver.OracleDriver 报错已经导入包了
报错信息：（试过换路径不管是tomcat 的目录还是项目的WEB-INF\lib 目录都运行不出来）
errordata
java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at dao.StudentDao.initConnection(StudentDao.java:29)
at dao.StudentDao.queryStuByName(StudentDao.java:44)
at prj2_1.QueryAction.execute(QueryAction.java:37)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException
at dao.StudentDao.queryStuByName(StudentDao.java:45)
at prj2_1.QueryAction.execute(QueryAction.java:37)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
加载的包：下面test项目是可以成功连接数据库的



连接代码：
try{
/*
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:" + "thin:@127.0.0.1:1521:XE","osky","osky123");
 System.out.println("连接成功！");
 */
System.out.println("开始尝试连接数据库！BBBB");
 Class.forName("oracle.jdbc.driver.OracleDriver");// 加载Oracle驱动程序
 System.out.println("开始尝试连接数据库！BBBB");
    System.out.println("开始尝试连接数据库！");
    String url = "jdbc:oracle:" + "thin:@127.0.0.1:1521:XE";// 127.0.0.1是本机地址，XE是精简版Oracle的默认数据库名
    String user = "osky";// 用户名,系统默认的账户名
    String password = "osky123";// 你安装时选设置的密码
    conn = DriverManager.getConnection(url, user, password);// 获取连接
    System.out.println("连接成功！");
}catch(Exception ex){ System.out.println("errordata");ex.printStackTrace();}
}