前几天为了在Tomcat5中配置MySql的数据源，在网上到处搜刮资料，最终仍未能配置成功。迫不得已，花了些银子买本书，看完后感觉收获很大。
再来配置数据源简直就是小菜一碟了，现将配置过程详述如下，一来作为版书的资料，二来希望为大家提供些帮助。
一、配置环境变量：
softe version:tomcat5.0.12/mysql4.1.7/mysql_driver---mysql-connector-java-3.1.4-beta-bin.jar
前几天为了在Tomcat5中配置MySql的数据源，在网上到处搜刮资料，最终仍未能配置成功。迫不得已，花了些银子买本书，看完后感觉收获很大。再来配置数据源简直就是小菜一碟了，现将配置过程详述如下，一来作为版书的资料，二来希望为大家提供些帮助。
一、配置环境变量：
softe version:tomcat5.0.12/mysql4.1.7/mysql_driver---mysql-connector-java-3.1.4-beta-bin.jar
mysql驱动程序可从www.mysql.com官方网站下载
路径：tomcat5在d:\myweb\tomcat5；mysql在C:\Program Files\MySQL\MySQL Server 4.1
Path(在原来的基础上加上）：d:\myweb\tomcat5\bin;d:\myweb\jdk1.4;d:\myweb\jdk1.4\bin;
d:\myweb\tomcat5\common\lib\servlet-api.jar;C:\Program Files\MySQL\MySQL Server 4.1\bin
CLASSPATH:d:\myweb\tomcat5\common\lib\servlet-api.jar;d:\myweb\tomcat5\common\lib\jsp-api.jar
JAVA_HOME:d:\myweb\jdk1.4
CATALINA_HOME:d:\myweb\tomcat5
二、建立测试数据库
在mysql中建立一个forumdb数据库，同时创建一个表member如下：
create database forumdb;
create table member
(
id int,
name varchar(6)
);
然后插入两条测试数据如下：
insert into member values(1,"zhang");
insert into member values(2,"wang");
至此，数据库准备完毕。
三、配置server.xml
注：我的web在d:\myweb\myapps
首先要将mysql的驱动程序放到d:\myweb\tomcat5\common\lib下面，一定要放".jar"的文件，如是".zip"的文件直接改为.jar即可。
用文本编辑器打开D:\tomcat5\conf\server.xml，找到</host>结束标志，然后在之前加上如下语句：
<Context path="/myapps" docBase="d:\myweb\myapps" debug="0"
reloadable="true" >
<Resource name="jdbc/DBConnection"
auth="Container"
type="javax.sql.DataSource" />
<ResourceParams name="jdbc/DBConnection">
<parameter>
<name>factory</name>
<value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
</parameter>
<!-- Maximum number of dB connections in pool. Make sure you
configure your mysqld max_connections large enough to handle
all of your db connections. Set to 0 for no limit.
-->
<parameter>
<name>maxActive</name>
<value>10</value>
</parameter>
<!-- Maximum number of idle dB connections to retain in pool.
Set to 0 for no limit.
-->
<parameter>
<name>maxIdle</name>
<value>3</value>
</parameter>
<!-- Maximum time to wait for a dB connection to become available
in ms, in this example 10 seconds. An Exception is thrown if
this timeout is exceeded. Set to -1 to wait indefinitely.
Maximum time to wait for a dB connection to become available
in ms, in this example 10 seconds. An Exception is thrown if
this timeout is exceeded. Set to -1 to wait indefinitely.
-->
<parameter>
<name>maxWait</name>
<value>10000</value>
</parameter>
<!-- MySQL dB username and password for dB connections -->
<parameter>
<name>username</name>
<value>root</value>
</parameter>
<parameter>
<name>password</name>
<value>1234</value>
</parameter>
<!-- Class name for mm.mysql JDBC driver -->
<parameter>
<name>driverClassName</name>
<value>com.mysql.jdbc.Driver</value>
</parameter>
<!-- The JDBC connection url for connecting to your MySQL dB.
The autoReconnect=true argument to the url makes sure that the
mm.mysql JDBC Driver will automatically reconnect if mysqld closed the
connection. mysqld by default closes idle connections after 8 hours.
-->
<parameter>
<name>url</name>
<value>jdbc:mysql://localhost:3306/forumdb?autoReconnect=true</value>
</parameter>
</ResourceParams>
</Context>
再次提醒：一定要放在</host>之前！
四、配置web.xml
web.xml位于d:\myweb\myapps\WEB-INF下，也即是你的WEB里的web.xml。
同样用文本编辑器打开web.xml，然后加入如下语句（在<web-app>与</web-app>之间）
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/DBConnection</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
五、编写测试jsp page。
在d:\myweb\myapps\下编写一个dbtest.jsp，代码如下：
<%@ page import="java.io.*,java.util.*,java.sql.*,javax.sql.*,javax.naming.*"%>
<%@ page contentType="text/html;charset=GB2312"%>
<html>
<head><title>DataSourse Connection Test</title></head>
<body>
<%
try{
java.sql.Connection con;
Statement stmt;
ResultSet rs;
Context ctx = new InitialContext();
DataSource ds=(DataSource)ctx.lookup("java:comp/env/jdbc/DBConnection");
con=ds.getConnection();
stmt=con.createStatement();
rs=stmt.executeQuery("select * from member");
while(rs.next()){
out.print(rs.getInt(1);
out.print(rs.getString(2));
}
rs.close();
stmt.close();
con.close();
}catch(Exception e){
out.print(e.getMessage());
}
%>
</body>
</html>
六、开始测试
运行tomcat.bat,打开IE在地址栏中输入：http://localhost:8080/myapps/dbtest.jsp
如果能够看到看到如下数据，恭喜你，成功了，若没有，说明还是有问题，只好再来了（通常都是最简单的拼错字符的问题）