@Configuration
public class OAConfig {
    @Autowired
    private ApplicationContext applicationContext;
    
    @Bean
    public PersonUtils personUtil(){
        boolean bool=applicationContext.containsBean("aa");
        System.out.println("containsBean:aa:
 
"+bool);
        return new PersonUtils();
    }
}



@Component
public class User {

    @Autowired
    private ApplicationContext applicationContext;
}

@Component
public class User{
    private ApplicationContext applicationContext;

    public User(ApplicationContext applicationContext) {
        
 
this.applicationContext = applicationContext;
    }
}

/**
 * Spring的ApplicationContext的持有者,可以用靜態方法的方式獲取spring容器中的bean
 *
 * @author yj
 * @date 2018年5月27日 下午6:32:11
 */
@Component
public class SpringContextHolder implements ApplicationContextAware {

    
 
private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextHolder.applicationContext = applicationContext;
    }

    public static ApplicationContext getApplicationContext() {
        assertApplicationContext();
        return applicationContext;
    }

    @SuppressWarnings("unchecked")
    public static <T> T getBean(String beanName) {
        assertApplicationContext();
        return (T) applicationContext.getBean(beanName);
    }

    public static <T> T getBean(Class<T> requiredType) {
        assertApplicationContext();
        return applicationContext.getBean(requiredType);
    }

    private static void assertApplicationContext() {
        if (SpringContextHolder.applicationContext == null) {
            throw new RuntimeException("applicaitonContext屬性為null,請檢查是否注入了SpringContextHolder!");
        }
    }

}