jdbc通过JNDI获取tomcat6连接池的连接
1.tomcat的server.xml中配置连接池

<Context docBase="HelloWeb" path="/HelloWeb" reloadable="true" source="org.eclipse.jst.jee.server:HelloWeb">      <Resource name="jdbc/msg"            auth="Container"            type="javax.sql.DataSource"            username="root"            password="root"            driverClassName="com.mysql.jdbc.Driver"            url="jdbc:mysql://localhost:3306/test"            maxActive="8"            maxIdle="4"/>      </Context>

2.将jdbc.driver的jar包拷到tomcat/lib文件夹下
3.获取数据库连接

Connection conn = null;try {Context initCtx = new InitialContext();Context envCtx = (Context) initCtx.lookup("java:comp/env");DataSource ds = (DataSource)  envCtx.lookup("jdbc/test"); conn = ds.getConnection();//conn.close();} catch (NamingException e) {e.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch block}