Spring导入外部资源

1. 创建一个数据库连接的 properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?serverTimezone=Asia/Shanghai&useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=admin888

2. 创建ApplicationContext.xml配置文件

<?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:con="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 https://www.springframework.org/schema/context/spring-context.xsd">

<!--    导入外部资源-->
<!--    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">-->
<!--        <property name="location" value="classpath:datasourse.properties"/>-->
<!--    </bean>-->

    <con:property-placeholder location="classpath:datasourse.properties"/>

    <bean id="datasource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driver}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>


</beans>

这里导入资源有两种方式,选择一种即可

• 第一种：已经过时了！

<!--    导入外部资源-->
    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:datasourse.properties"/>
    </bean>

• 第二种：Spring推荐使用的

 <con:property-placeholder location="classpath:datasourse.properties"/>

3. 创建一个测试类

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("ApplicationContext.xml");

        DruidDataSource datasource = context.getBean("datasource", DruidDataSource.class);
        System.out.println(datasource);


    }
}

4. 运行结果