手动加载

#properties文件
jdbc.driver=1

<?xml version="1.0" encoding="UTF-8"?>
<!--        开启context命名空间-->
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       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.xsd
">
    <!--    使用context空间加载properties-->
    <context:property-placeholder location="jdbc.properties,jdbc2.properties"/>
<!--    使用属性占位符${}读取properties文件中的属性-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="2"/>
        <property name="user" value="3"/>
        <property name="password" value="4"/>
    </bean>
</beans>

package org.example;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import javax.sql.DataSource;

public class AppForDIAtuoware {
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        DataSource dataSource = (DataSource) ctx.getBean("dataSource");
        System.out.println(dataSource);
    }
}

技巧

用通配符*可以加载所有properties文件,注意标明路径

同时只能导入本地的文件

  <context:property-placeholder location="classpath:*.properties"/>

更通用

  <context:property-placeholder location="classpath*:*.properties"/>

总结