tomcat怎么配置数据源

<resource><name>jdbc/myDataSource</name><type>javax.sql.DataSource</type></resource>

<resource>  ...  <property><name>url</name><value>jdbc:mysql://localhost:3306/mydatabase</value></property><property><name>username</name><value>root</value></property><property><name>password</name><value></value></property></resource>

<resource>  ...  <property><name>driverClassName</name><value>com.mysql.jdbc.Driver</value></property><property><name>maxActive</name><value>10</value></property><property><name>maxIdle</name><value>5</value></property></resource>

Context initContext = new InitialContext();Context envContext = (Context) initContext.lookup("java:comp/env");DataSource dataSource = (DataSource) envContext.lookup("jdbc/myDataSource");