Tomcat 中Jndi是使用Tomcat自带的连接池，由于客户要求，抛弃Tomcat自带的连接池。使用c3p0 。经过几个小时调试，解决方案如下：
环境：Tomcat 6
下面来看Jndi 与 c3p0 结合：
下载地址：http://nchc.dl.sourceforge.net/sourceforge/
c3p0/c3p0c3p0-0.9.0.4.bin.zip
把 c3p0-0.9.0.4.jar 放到应用服务的%tomcat6%/lib目录下。如：
1.在context.xml中<Context></Context>内加<Resource />，完整的示例：
<?xml version='1.0' encoding='utf-8'?>
<Context> <WatchedResource>WEB-INF/web.xml</WatchedResource>
<!-- 下面注释部分为使用jndi+tomcat自带的连接池-->
<!--<Resource name="jdbc/ctitc" type="javax.sql.DataSource"
username="business" password="ctitc" driverClassName="oracle.jdbc.driver.OracleDriver" url="jdbc:oracle:thin:@127.0.0.1:1521:FJTDC"
maxIdle="30" maxWait="5000" maxActive="100"/>
-->
<!-- 下面注释部分为使用jndi+c3p0-->
<Resource name="jdbc/ctitc"
type="com.mchange.v2.c3p0.ComboPooledDataSource"
maxPoolSize="50" minPoolSize="2" acquireIncrement="2"
factory="org.apache.naming.factory.BeanFactory"
user="user" password=""
driverClass="oracle.jdbc.driver.OracleDriver"
jdbcUrl="jdbc:oracle:thin:@127.0.0.1:1521:ORCL"
/> </Context>
2.在web.xml添加：
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/ctitc</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
3.与spring结合，代码如下
<bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="java:comp/env/jdbc/ctitc"/>
</bean>
4.使用oracle数据库的rac插件时url地址的写法
两台小机没做os集群，只做了oracle RAC，A机虚拟ip为192.168.30.51，标识符为kms1；B机虚拟ip为192.168.30.52，标识符为kms2。关键的连接字符串如下：
url=jdbc:oracle:thin:@(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.30.51)(PORT = 1521))(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.30.52)(PORT = 1521))(LOAD_BALANCE = yes)(FAILOVER = yes)(CONNECT_DATA =(SERVER = DEDICATED)(SERVICE_NAME = kms)(FAILOVER_MODE=(TYPE = SELECT)(METHOD = BASIC)(RETIRES = 20)(DELAY = 15))))
注：不同的版本有不同的连接方式，tomcat5.5版本的连接方式参见
http://www.cnblogs.com/koal/p/4367676.html