我的六分钱:

BeanFactory and ApplicationContext both are interfaces where ApplicationContext extends BeanFactory. So ApplicationContext is a child interface and BeanFactory is the parent interface. In other words, ApplicationContext has all the features of BeanFactory and it has some additional features that are not present in BeanFactory. BeanFactory loads beans on-demand that is Lazy Loading whereas ApplicationContext loads all beans at startup that is Eager Loading. BeanFactory does not support annotations whereas ApplicationContext supports annotations. ApplicationContext has additional features that are not present in BeanFactory: Internationalization, Event Publishing, AOP features. BeanFactory only supports two scopes — Singleton and Prototype whereas ApplicationContext supports all bean scopes. BeanFactory does not register BeanFactoryPostProcessor and BeanPostProcessor automatically whereas ApplicationContext automatically registers them.

在实时场景中，Spring IOC核心容器(BeanFactory)和高级J2EE容器(ApplicationContext)之间的区别如下。

BeanFactory will create objects for the beans (i.e., for POJO classes) mentioned in the spring.xml file (<bean></bean>) only when you call the .getBean() method, but whereas ApplicationContext creates the objects for all the beans (<bean></bean> if its scope is not explicitly mentioned as "Prototype") configured in the spring.xml while loading the spring.xml file itself. BeanFactory: (Lazy container because it creates the objects for the beans only when you explicitly call from the user/main class) /* * Using core Container - Lazy container - Because it creates the bean objects On-Demand */ //creating a resource Resource r = (Resource) new ClassPathResource("com.spring.resources/spring.xml"); //creating BeanFactory BeanFactory factory=new XmlBeanFactory(r); //Getting the bean for the POJO class "HelloWorld.java" HelloWorld worldObj1 = (HelloWorld) factory.getBean("test"); ApplicationContext: (Eager container because of creating the objects of all singleton beans while loading the spring.xml file itself) ApplicationContext context = new ClassPathXmlApplicationContext("com/ioc/constructorDI/resources/spring.xml"); Technically, using ApplicationContext is recommended because in real-time applications, the bean objects will be created while the application is getting started in the server itself. This reduces the response time for the user request as the objects are already available to respond.

参考Spring Docs中的这个文档:

http://static.springsource.org/spring/docs/3.2.x/spring-framework-reference/html/beans.html#context-introduction-ctx-vs-beanfactory

5.15.1 bean工厂还是应用上下文?

使用ApplicationContext，除非你有很好的理由不这样做。

Because the ApplicationContext includes all functionality of the BeanFactory, it is generally recommended over the BeanFactory, except for a few situations such as in an Applet where memory consumption might be critical and a few extra kilobytes might make a difference. However, for most typical enterprise applications and systems, the ApplicationContext is what you will want to use. Spring 2.0 and later makes heavy use of the BeanPostProcessor extension point (to effect proxying and so on). If you use only a plain BeanFactory, a fair amount of support such as transactions and AOP will not take effect, at least not without some extra steps on your part. This situation could be confusing because nothing is actually wrong with the configuration.

BeanFactory和ApplicationContext的区别如下:

BeanFactory uses lazy initialization but ApplicationContext uses eager initialization. In case of BeanFactory, bean is created when you call getBeans() method, but bean is created upfront in case of ApplicationContext when the ApplicationContext object is created. BeanFactory explicitly provide a resource object using syntax but ApplicationContext creates and manages resource objects on its own. BeanFactory doesnt support internatiolization but ApplicationContext supports internationalization. With BeanFactory annotation based dependency injection is not supported but annotation based dependency injection is supported in ApplicationContext.

使用BeanFactory:

BeanFactory beanfactory = new XMLBeanFactory(new FileSystemResource("spring.xml"));
 Triangle triangle =(Triangle)beanFactory.getBean("triangle");

使用ApplicationContext:

ApplicationContext context = new ClassPathXMLApplicationContext("spring.xml")
Triangle triangle =(Triangle)context.getBean("triangle");

我需要解释BeanFactory & ApplicationContext。

BeanFactory: BeanFactory is root interface for accessing the SpringBean Container.There is basic client view of a bean container. That interface is implemented by the object class that holds the number of beans definitions, and each uniquely identify by the String name Depending the Bean definition the factory will return the instance that instance may be the instance of contained object or a single shared instance. Which type of instance will be return depends of bean factory configuration. Normally Bean factory will load the all the all the beans definition, which stored in the configuration source like XML...etc.

BeanFactory是一个为依赖注入提供基本支持的最简单的容器

应用程序上下文 应用程序上下文是spring应用程序中的一个中心接口，它向应用程序提供配置信息。它实现了Bean工厂接口。

应用程序上下文是一个高级容器，它增加了高级级别的企业特定功能，例如从属性文件....解析文本消息的能力等

一个ApplicationContext提供:

Bean factory methods for accessing application components. Inherited from ListableBeanFactory. The ability to load file resources in a generic fashion. Inherited from the ResourceLoader interface. The ability to publish events to registered listeners. Inherited from the ApplicationEventPublisher interface. The ability to resolve messages, supporting internationalization. Inherited from the MessageSource interface. Inheritance from a parent context. Definitions in a descendant context will always take priority. This means, for example, that a single parent context can be used by an entire web application, while each servlet has its own child context that is independent of that of any other servlet. In addition to standard BeanFactory lifecycle capabilities, ApplicationContext implementations detect and invoke ApplicationContextAware beans as well as ResourceLoaderAware, ApplicationEventPublisherAware and MessageSourceAware beans.

在非web应用程序中使用BeanFactory，因为它只支持单例和原型bean作用域。

而ApplicationContext容器确实支持所有的bean作用域，所以你应该将它用于web应用程序。