这个类是用来解析Java Properties属性文件值,并提供在spring配置期间替换使用属性值。以下是它的三种常见使用方法。 (1).基本的使用方法: spring-config.xml <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location"> <value>classpath:/spring/include/dbQuery.properties</value> </property> </bean> 其中classpath是引用src目录下的文件写法。 (2).当存在多个Properties文件时,配置就需使用locations了: spring-config.xml <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="locations"> <list> <value>classpath:/spring/include/jdbc-parms.properties</value> <value>classpath:/spring/include/base-config.properties</value> </list> </property> </bean> (3).接下来我们要使用多个PropertyPlaceholderConfigurer来分散配置,达到整合多工程下的多个分散的Properties文件,其配置如下 Xml代码 <bean id="propertyConfigurerForProject1" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="order" value="1" /> <property name="ignoreUnresolvablePlaceholders" value="true" /> <property name="location"> <value>classpath:/spring/include/dbQuery.properties</value> </property> </bean> Xml代码 <bean id="propertyConfigurerForProject2" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="order" value="2" /> <property name="ignoreUnresolvablePlaceholders" value="true" /> <property name="locations"> <list> <value>classpath:/spring/include/jdbc-parms.properties</value> <value>classpath:/spring/include/base-config.properties</value> </list> </property> </bean> 其中order属性代表其加载顺序,而ignoreUnresolvablePlaceholders为是否忽略不可解析的Placeholder,如配置了多个PropertyPlaceholderConfigurer,则需设置为true。