在xml文件里获取jvm环境变量

 1    <context-param>
 2              <param-name> contextConfigLocation</param-name >
 3              <param-value>
 4                   file:${home}${file.separator}amn_sms${file.separator} config${file.separator}context.xml
 5              </param-value>
 6    </context-param>
 7    <listener>
 8              <listener-class>
 9                   org.springframework.web.context.ContextLoaderListener
10              </listener-class>
11     </listener>