spring面试题

1.springboot自动装配

从 这个META-INF/spring-autoconfigure-metadata.properties加载文件

2.springbean 的生命周期

3.spring 如何解绝循环依赖

private final Map<String, Object> earlySingletonObjects = new ConcurrentHashMap<>(16); private final Map<String, Object> singletonObjects = new ConcurrentHashMap<>(256); private final Map<String, ObjectFactory<?>> singletonFactories = new HashMap<>(16); synchronized (this.singletonObjects) { Object singletonObject = this.singletonObjects.get(beanName); if (singletonObject == null) { beforeSingletonCreation(beanName); try { singletonObject = singletonFactory.getObject(); newSingleton = true; } catch (IllegalStateException ex) { singletonObject = this.singletonObjects.get(beanName); } finally { afterSingletonCreation(beanName); } if (newSingleton) { addSingleton(beanName, singletonObject); } } return singletonObject; }

4. spring cloud zuul 的类型

 forward SendForwardFilter，SimpleHostRoutingFilter

 pre   PreDecorationFilter，FormBodyWrapperFilter，DebugFilter

 post   LocationRewriteFilter，SendErrorFilter，SendResponseFilter

5.spring cloud 的 eureka 的负载保护