请教高手 急

我是这样配置的 。全局数据库连接池(Mysql数据库)
1、通过管理界面配置连接池，或者直接在tomcat\conf\server.xml的GlobalNamingResources中增加
<Resource auth="Container" description="DB Connection" driverClass="com.mysql.jdbc.Driver" maxPoolSize="10" minPoolSize="2" acquireIncrement="2" name="jdbc/mysqlDB" user="root" password="111111" factory="org.apache.naming.factory.BeanFactory" type="com.mchange.v2.c3p0.ComboPooledDataSource" jdbcUrl="jdbc:mysql://localhost:3306/first?autoReconnect=true" /> 
2、在tomcat\webapps\myapp\META-INF\context.xml的Context中增加： <ResourceLink name="jdbc/mysqlDB" global="jdbc/mysqlDB" type="javax.sql.DataSource"/>
这样就可以了。然后测试程序是<%@page language="java" import="java.util.*,java.sql.*,javax.naming.*,javax.sql.*" pageEncoding="GB2312"%><%@page import="java.sql.Connection"%>
<%@page import="com.mchange.v2.c3p0.*"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>    
    <title>My JSP 'mysqlTest.jsp' starting page</title>
</head><body>
    Mysql数据库测试<br><br><br>
    <%
    Connection conn=null;
    PreparedStatement ps=null;
    ResultSet rs=null;
      try
{
      InitialContext ctx = new InitialContext(); 
      DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/mysqlDB"); 
      conn=ds.getConnection();
      String sql="select * from t";
      ps=conn.prepareStatement(sql);
       rs=ps.executeQuery();
      
}
catch(NamingException ex)
{
   ex.printStackTrace();
}    
  
   
      
    
   
   if(rs!=null)
   {
       rs.close();
       rs=null;
   }
   if(ps!=null)
   {
       ps.close();
       ps=null;
   }
    
    if(conn!=null)
    {
        conn.close();
        conn=null;
    }
    %>
    I hate you
</body>
</html>
这样可以运行出现Mysql数据库测试
I hate you 可是不能出现，如在成序中加入rs.getInt(1);就报错。
org.apache.jasper.JasperException: Exception in JSP: /luck.jsp:3633:     
34: 
35: 
36:   rs.getInt(1);
37:    
38:       
39:     

解决方案 »

  1.   

    改成rs.getString(1);或者rs.getString("你的字段名");
      

  2.   

    单纯加上rs.getInt(1); 肯定不行，楼主不会真的是这样吧？？
      

  3.   

    ResultSet 对象具有指向其当前数据行的指针。最初，指针被置于第一行之前
    所以要先调用next方法 将指针置于第一行
      

  4.   

    对不起人民，可是加了之后是
    org.apache.jasper.JasperException: Exception in JSP: /luck.jsp:3734: 
    35:     
    36: 
    37: if(rs.next())
    38:   rs.getInt("id");
    39:    
      

  5.   

    if(rs.next()) 
    {
     System.out.println(rs.getString("id")); 
    }
    加上括号啊-_-!
      

  6.   

    这是异常信息，
    javax.naming.NamingException: Class not found: com.mchange.v2.c3p0.ComboPooledDataSource
    at org.apache.naming.factory.BeanFactory.getObjectInstance(BeanFactory.java:136)
    at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:140)
    at javax.naming.spi.NamingManager.getObjectInstance(Unknown Source)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:793)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:153)
    at org.apache.naming.factory.ResourceLinkFactory.getObjectInstance(ResourceLinkFactory.java:97)
    at javax.naming.spi.NamingManager.getObjectInstance(Unknown Source)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:793)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
    at org.apache.naming.NamingContext.lookup(NamingContext.java:153)
    at org.apache.naming.SelectorContext.lookup(SelectorContext.java:137)
    at javax.naming.InitialContext.lookup(Unknown Source)
    at org.apache.jsp.luck_jsp._jspService(luck_jsp.java:71)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:875)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    at java.lang.Thread.run(Unknown Source)
    2008-10-31 10:59:27 org.apache.catalina.core.StandardWrapperValve invoke
    严重: Servlet.service() for servlet jsp threw exception
    java.lang.NullPointerException
    at org.apache.jsp.luck_jsp._jspService(luck_jsp.java:85)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:875)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    at java.lang.Thread.run(Unknown Source)可是我导入包了。
      

  7.   

    还是不对
    org.apache.jasper.JasperException: Exception in JSP: /luck.jsp:3734: 
    35:     
    36: 
    37: if(rs.next()) 
    38: { 
    39: System.out.println(rs.getString("id")); 
    40: } 
      

  8.   

    终于搞定了，从eclipse导入包还不行，呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜呜
    还要加到tomcat中。
    为什么呢？？？？？？？？？？？？？？？？？？？？？？？？？、、、、、
      

  9.   

    因为你的是连接池.在Tomcat启动的时候它就要创建连接池了,它不管你有没有项目,你有可能是没有项目的,而的驱动包却是放在项目下边,所以不行.要放在Tomcat里