在spring3.1中怎么在annotation中注入properties中的值

在spring3.1中如何在annotation中注入properties中的值
spring.scheduler.cron = 0 0 0 0

??

???? 步骤2：????

<context:property-placeholder location="classpath:drm.properties" ignore-unresolvable="true"/> 

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? ? 步骤3：????

        private String cron = null;@Value("${spring.scheduler.cron}")public void setCron(String cron) {this.cron = cron;}

?