高分；关于数据库连接池的有关问题
日期：2014-05-18 浏览次数：20704 次
高分；关于数据库连接池的问题
环境：Tomcat5.0.25 + jdk1.4+ mysql+Winxp
首先在http://localhost/admin 创建数据源
写了个jsp测试
<!doctype html public "-//w3c//dtd html 4.0 transitional//en "
"http://www.w3.org/TR/REC-html40/strict.dtd ">
<%@ page import= "java.sql.* "%>
<%@ page import= "javax.sql.* "%>
<%@ page import= "javax.naming.* "%>
<%@ page session= "false " %>
<%@ page contentType= "text/html; charset=gb2312 " %>
<html>
<body>
<meta http-equiv= "Content-Type " content= "text/html; charset=gb2312 ">
<title> </title>
<%
DataSource ds = null;
try{
InitialContext ctx=new InitialContext();
ds=(DataSource)ctx.lookup( "java:comp/env/jdbc/mysql ");
Connection conn = ds.getConnection();
Statement stmt = conn.createStatement();
String strSql = " select * from student ";
ResultSet rs = stmt.executeQuery(strSql);
while(rs.next()){
out.print(rs.getString(1));
}
out.print( "over ");
}
catch(Exception ex){
out.print( "Error occur: "+ex.getMessage());
ex.printStackTrace();
}
%>
</body>
</html>
但是报错如下；Error occur:Cannot create JDBC driver of class ' ' for connect URL 'null '
很郁闷。高手看看是怎么回事。谢谢 ！
------解决方案--------------------
这是我用的，没问题，你试一下
首先：在tomcat目录下的conf目录中建立路径Catalina\localhost，在新建的目录下建立xml文件，注意：名称最好和工程名相同。在里面加入如下内容
<?xml version= "1.0 " encoding= "UTF-8 "?>
<Context displayName= "MessageBoard " docBase= "MessageBoard " path= "/MessageBoard " workDir= "work\Catalina\localhost\Messageboard ">
<Resource auth= "Container " name= "MessageBoard/jdbc/Data " type= "javax.sql.DataSource "> </Resource>
<ResourceParams name= "MessageBoard/jdbc/Data ">
<parameter>
<name> factory </name>
<value> org.apache.commons.dbcp.BasicDataSourceFactory </value>
</parameter>
<parameter>
<name> maxActive </name>
<value> 100 </value>
</parameter>
<parameter>
<name> maxIdle </name>
<value> 30 <
环境：Tomcat5.0.25 + jdk1.4+ mysql+Winxp
首先在http://localhost/admin 创建数据源
写了个jsp测试
<!doctype html public "-//w3c//dtd html 4.0 transitional//en "
"http://www.w3.org/TR/REC-html40/strict.dtd ">
<%@ page import= "java.sql.* "%>
<%@ page import= "javax.sql.* "%>
<%@ page import= "javax.naming.* "%>
<%@ page session= "false " %>
<%@ page contentType= "text/html; charset=gb2312 " %>
<html>
<body>
<meta http-equiv= "Content-Type " content= "text/html; charset=gb2312 ">
<title> </title>
<%
DataSource ds = null;
try{
InitialContext ctx=new InitialContext();
ds=(DataSource)ctx.lookup( "java:comp/env/jdbc/mysql ");
Connection conn = ds.getConnection();
Statement stmt = conn.createStatement();
String strSql = " select * from student ";
ResultSet rs = stmt.executeQuery(strSql);
while(rs.next()){
out.print(rs.getString(1));
}
out.print( "over ");
}
catch(Exception ex){
out.print( "Error occur: "+ex.getMessage());
ex.printStackTrace();
}
%>
</body>
</html>
但是报错如下；Error occur:Cannot create JDBC driver of class ' ' for connect URL 'null '
很郁闷。高手看看是怎么回事。谢谢 ！
------解决方案--------------------
这是我用的，没问题，你试一下
首先：在tomcat目录下的conf目录中建立路径Catalina\localhost，在新建的目录下建立xml文件，注意：名称最好和工程名相同。在里面加入如下内容
<?xml version= "1.0 " encoding= "UTF-8 "?>
<Context displayName= "MessageBoard " docBase= "MessageBoard " path= "/MessageBoard " workDir= "work\Catalina\localhost\Messageboard ">
<Resource auth= "Container " name= "MessageBoard/jdbc/Data " type= "javax.sql.DataSource "> </Resource>
<ResourceParams name= "MessageBoard/jdbc/Data ">
<parameter>
<name> factory </name>
<value> org.apache.commons.dbcp.BasicDataSourceFactory </value>
</parameter>
<parameter>
<name> maxActive </name>
<value> 100 </value>
</parameter>
<parameter>
<name> maxIdle </name>
<value> 30 <
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