Spring bean实例化排序

Question

@Service ("bean3")   
 public class Bean3 implements ApplicationListener  { 
    public void onApplicationEvent() {  
      //load data from DB and populate cache                    
    }
     public void getCache(){
     //get data from cache
    }

@Service ("bean2")
public class Bean2 { 
@Autowired 
private Bean3 bean3;
   private void methodA(){
     bean3.getCache();
   }
}

JAR2（非Spring项目）

public class Bean1{  
Bean2 bean2 = SpringServiceLocator.getBean("bean2")
  public void methodB(){
    bean2.methodA();
   } 
}

Answer 1

如果我没有理解错的话，您正在尝试对应用程序启动（上下文初始化）执行一些逻辑。

如果是这种情况，我建议您使用BeanPostProcessor在应用程序启动时执行任何特殊操作。

public class MyBeanPostProcessor implements BeanPostProcessor {

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName)
            throws BeansException {

        .. **perform special things**
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName)
            throws BeansException {
        ..**perform special things**
        return bean;
    }
}

不要忘记告诉Spring关于您的后处理器

<context:component-scan base-package="some.package" />
<bean class="some.package.MyBeanPostProcessor"