请教个连接TOMCAT的问题


<%@ page contentType="text/html; charset=gb2312" %>  <%@ page language="java" %>  <%@ page import="com.mysql.jdbc.Driver" %>  <%@ page import="java.sql.*" %>
<html>
<body>
  <%  //驱动程序名  String driverName="com.mysql.jdbc.Driver";  //数据库用户名  String userName="root";  //密码  String userPasswd="123456";  //数据库名  String dbName="student";  //表名  String tableName="studentinfo";  //联结字符串  String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPasswd;  Class.forName("com.mysql.jdbc.Driver").newInstance();  Connection conn=DriverManager.getConnection(url);  Statement statement = conn.createStatement();  String sql="SELECT * FROM "+tableName;  ResultSet rs = statement.executeQuery(sql);   //获得数据结果集合  ResultSetMetaData rmeta = rs.getMetaData();  //确定数据集的列数，亦字段数  int numColumns=rmeta.getColumnCount();  // 输出每一个数据值  out.print("id");   out.print("|");  out.print("num");  out.print("<br>");  while(rs.next()) {  out.print(rs.getString(1)+" ");   out.print("|");  out.print(rs.getString(2));  out.print("<br>");   }   out.print("<br>");  out.print("数据库操作成功，恭喜你");   rs.close();   statement.close();   conn.close();   %> 
</body>
</html>我先前已经把mysql-connector-java-5.0.4-bin.jar复制到TOMCAT6.0了,现在上面的代码放到webapps/JDBC下的JSP中
http://localhost:8080/jdbc/a.jsp 还是运行不出啊type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /a.jsp at line 3734: 
35:   Class.forName("com.mysql.jdbc.Driver").newInstance();
36: 
37:   Connection conn=DriverManager.getConnection(url);
38: 
39:   Statement statement = conn.createStatement();
40: 
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:398)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause javax.servlet.ServletException: java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:862)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:791)
org.apache.jsp.a_jsp._jspService(a_jsp.java:149)
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:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:946)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2870)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:812)
com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3269)
com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1182)
com.mysql.jdbc.Connection.createNewIO(Connection.java:2670)
com.mysql.jdbc.Connection.<init>(Connection.java:1531)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
java.sql.DriverManager.getConnection(Unknown Source)
java.sql.DriverManager.getConnection(Unknown Source)
org.apache.jsp.a_jsp._jspService(a_jsp.java:92)
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:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.20 logs.
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解决方案 »

  1.   

    首先你先参考Apache Tomcat/6.0.20 logs！看看出错的原因是什么。
    其次，有servlet exception ，看看该导的包都导了没！
    最后是检查你的本地mysql root是否有密码的root用户，可以先自行在console链接测试看看！
      

  2.   

    从代码上没有看出问题，是'root'@'localhost'的问题，你在mysql中执行下面语句然后再试试：
    grant all on *.* to 'user@host';
      

  3.   


    或者
    jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPasswd;你的mysql的端口你更改过了？否则应该是
    jdbc:mysql://localhost:3306/"+dbName+"?user="+userName+"&password="+userPasswd;