<%@ page contentType="text/html; charset=GBK" %>
<%@ page import="java.sql.*, poolsample.*"%>
<html>
<head>
<title>
PoolDemo
</title>
</head>
<body bgcolor="#ffffff">
<center>
<h2>
<font color=darkblue>
连接数据库
</font>
</h2>
</center>
<table width="70%" align=center>
<tr>
<td align=center>
<% //调用ConnectionPool的方法初始化一个ConnManager对象
ConnManager polledConnection = ConnectionPool.getPolledConn(); if (polledConnection!=null){
//通过ConnManager对象的getConnection()可以得到一个物理Connection
Connection _conn = polledConnection.getConnection();
if (_conn!=null){
out.println("<h3><font color=red>create a Phyical JDBC Connection successfully<font color=darkblue></h3>");
ResultSet _rs = null ;
Statement _state = null ;
%>
<table>
<tr>
<td align=center>
<%
//执行SQL语句,并输出结果
try{
_state = _conn.createStatement() ;
String _sSQL = "select * from Node" ;
_rs = _state.executeQuery(_sSQL) ;
ResultSetMetaData _rsmd = _rs.getMetaData() ;
int _iColCount = _rsmd.getColumnCount() ;
System.out.println(_iColCount);
if(_iColCount>0)
{
out.println("您所访问的表共有 "+_iColCount+"列,列名为:"); %>
</td></tr>
<%
for (int i = 1 ; i <= _iColCount ;i++)
{
out.println("<tr><td align=center><font color=darkblue>"+_rsmd.getColumnLabel(i)+"<font color=darkblue></td></tr>");
}
}
_rs.close();
_state.close();
}catch(Exception er){
er.printStackTrace() ;
}finally{
//执行操作完成后,客户不需要自己关闭连接,只需要将连接release即可。连接的关闭由连接池来管理
polledConnection.release(); }
}
}%>
</table>
</td>
</tr>
</table></body>
</html>这个运行的时候不能正常运行,要怎么解决啊?谢谢了!
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception javax.servlet.ServletException: poolsample/ConnManager
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:272)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause java.lang.NoClassDefFoundError: poolsample/ConnManager
java.lang.Class.getDeclaredConstructors0(Native Method)
java.lang.Class.privateGetDeclaredConstructors(Class.java:2328)
java.lang.Class.getConstructor0(Class.java:2640)
java.lang.Class.newInstance0(Class.java:321)
java.lang.Class.newInstance(Class.java:303)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:138)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:305)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.12 logs.
<%@ page import="java.sql.*, poolsample.*"%>
<html>
<head>
<title>
PoolDemo
</title>
</head>
<body bgcolor="#ffffff">
<center>
<h2>
<font color=darkblue>
连接数据库
</font>
</h2>
</center>
<table width="70%" align=center>
<tr>
<td align=center>
<% //调用ConnectionPool的方法初始化一个ConnManager对象
ConnManager polledConnection = ConnectionPool.getPolledConn(); if (polledConnection!=null){
//通过ConnManager对象的getConnection()可以得到一个物理Connection
Connection _conn = polledConnection.getConnection();
if (_conn!=null){
out.println("<h3><font color=red>create a Phyical JDBC Connection successfully<font color=darkblue></h3>");
ResultSet _rs = null ;
Statement _state = null ;
%>
<table>
<tr>
<td align=center>
<%
//执行SQL语句,并输出结果
try{
_state = _conn.createStatement() ;
String _sSQL = "select * from Node" ;
_rs = _state.executeQuery(_sSQL) ;
ResultSetMetaData _rsmd = _rs.getMetaData() ;
int _iColCount = _rsmd.getColumnCount() ;
System.out.println(_iColCount);
if(_iColCount>0)
{
out.println("您所访问的表共有 "+_iColCount+"列,列名为:"); %>
</td></tr>
<%
for (int i = 1 ; i <= _iColCount ;i++)
{
out.println("<tr><td align=center><font color=darkblue>"+_rsmd.getColumnLabel(i)+"<font color=darkblue></td></tr>");
}
}
_rs.close();
_state.close();
}catch(Exception er){
er.printStackTrace() ;
}finally{
//执行操作完成后,客户不需要自己关闭连接,只需要将连接release即可。连接的关闭由连接池来管理
polledConnection.release(); }
}
}%>
</table>
</td>
</tr>
</table></body>
</html>这个运行的时候不能正常运行,要怎么解决啊?谢谢了!
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception javax.servlet.ServletException: poolsample/ConnManager
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:272)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause java.lang.NoClassDefFoundError: poolsample/ConnManager
java.lang.Class.getDeclaredConstructors0(Native Method)
java.lang.Class.privateGetDeclaredConstructors(Class.java:2328)
java.lang.Class.getConstructor0(Class.java:2640)
java.lang.Class.newInstance0(Class.java:321)
java.lang.Class.newInstance(Class.java:303)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:138)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:305)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.12 logs.
你在仔细看看,而我还想提醒你一下,你用的是连接池来完成数据库的连接的,这样的话你还应该在server.xml中配置数据源,这样你的java类才能正常的工作。也正是这样你才能得到正确的结果哟!你再看看是不是这样!