spring 读取properties的两种方法

一：直接使用context命名空间

如：

<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"   xmlns:websocket="http://www.springframework.org/schema/websocket"   xsi:schemaLocation="http://www.springframework.org/schema/beans       http://www.springframework.org/schema/beans/spring-beans.xsd      http://www.springframework.org/schema/websocket         http://www.springframework.org/schema/websocket/spring-websocket.xsd      http://www.springframework.org/schema/context       http://www.springframework.org/schema/context/spring-context.xsd">

<context:property-placeholder location="classpath:log4j.properties" />

二：在配置文件中配置PropertyPlaceholderConfigurer

<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">   <property name="locations" value="classpath:jdbc.properties" />  </bean>

然后在需要的地方直接以下方式引用

<property name="url" value="${jdbc.url}"/>