从jndi获取数据源

目前还不知道这种方式有啥用,但是既看到了就先记下来再说
1.spring配置文件中是怎么定义的
<bean id="dataSource"
class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName">
<value>java:/comp/env/PortalONEServiceDB</value>
</property>

</bean>
2.tomcat server.xml中定义
<Resource name="DevPortalDB" auth="Container"
type="javax.sql.DataSource" initialSize="5" minIdle="5" maxActive="5"
maxIdle="5" maxWait="6000" username="devuser_sit" password="tDiZ9+dCIz3LPVGXvEgfhA=="
driverClassName="oracle.jdbc.driver.OracleDriver"
url="jdbc:oracle:thin:@10.137.41.105:1521:MDSPDB"
validationQuery="select 1 from dual" testOnBorrow="true" />

3.在tomcat\conf\Catalina\localhost下建一个xml
<Context path="/devPortal" docBase="E:/working1/devportal/WebRoot"
debug="0" crossContext="true">
<ResourceLink global='DevPortalDB' name='PortalONEServiceDB' type="javax.sql.Datasource"/>
</Context>