如何从服务层访问spring托管bean

我无法在服务层(ServiceContext.getBean(“beanName”)中获取SpringBean)。不过,我可以在servlet中获取bean。下节课我做错什么了?

package com.ekaplus.presentation.common;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public class ServiceContext implements ApplicationContextAware{

    private static ApplicationContext applicationContext;       

    @SuppressWarnings("static-access")
    public  void setApplicationContext(ApplicationContext ctx)throws BeansException {
        this.applicationContext=ctx;        
    }
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }
    public static Object getBean(String beanName)
    {
        return applicationContext.getBean(beanName);
    }

}