解决方法
Which is the default scope of a Spring 4 @Service?
默认范围是单例
It is reasonable to design a Service implementation in order to store some info,related to the current logged user (according to the current HTTP session)
是.在这种情况下,服务将必须有范围“会话”.见http://docs.spring.io/spring/docs/current/spring-framework-reference/html/beans.html#beans-factory-scopes-other