spring中bean配置8.0版本数据库（使用属性文件配置）

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:p="http://www.springframework.org/schema/p"
  xmlns:context="http://www.springframework.org/schema/context"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
  <!-- 导入context来引入属性文件 -->
  <context:property-placeholder location="classpath:db.properties"/>
  <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    p:user="${user}" 
    p:password="${password}"
    p:driverClass="${driverclass}"
    p:jdbcUrl="${jdbcurl}">
  </bean>
</beans>

user=root
password=123456
driverclass=com.mysql.cj.jdbc.Driver
jdbcurl=jdbc:mysql://localhost:3306/daname?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8

package springDemo.properties;
import java.sql.SQLException;
import javax.sql.DataSource;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
  public static void main(String[] args) throws SQLException {
    // TODO Auto-generated method stub
    ApplicationContext ctx =  new ClassPathXmlApplicationContext("beans-properties.xml");
    DataSource dataSource = (DataSource)ctx.getBean("dataSource");
    System.out.println(dataSource.getConnection());
  }
}