applicationContext.xml

    <!-- 定义受环境影响易变的变量 -->
    <context:property-placeholder location="classpath*:application.properties" />
    <bean id="configBean" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <value>classpath*:application.properties</value>
        </property>
    </bean>

    <!--Spring整合MyBatis框架-->
    <!--配置连接池-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://rm-uf623m5846lr33extpo.mysql.rds.aliyuncs.com:3306/stzb?serverTimezone=UTC"/>
        <property name="user" value="stzb"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

application.properties