1. configure PropertyPlaceholderConfigurer [html] <bean class = "org. springframework. beans. factory. config. propertyplaceholderpolicer "> <property name =" locations "value =" classpath: com/foo/jdbc. properties "/> </bean> and then reference it directly in the following way: [html] <property name =" url "value =" $ {jdbc. url} "/> 2. the namespace Declaration for adding beans to the configuration file is as follows: [html <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: aop = "http://www.springframework.org/schema/aop" xmlns: tx = "http://www.springframework.org/schema/tx" xsi: schemaLocation = "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/context"> used [html] xmlns: context = configuration as follows: [html] <context: property-placeholder location = "dbconf. properties "/>