Posted in: ApplicationContext In Spring,Bean Lifecycle in Spring,Bean scopes in Spring,Spring Framework,Spring IoC,Spring MVC Introduction
Bean Creation :
- Direct instantiation
- <bean id=“beanId” class=“className”>
- BeanFactory instantiation
- Same syntax but class is subclass of BeanFactory
- getObject() called to obtain Bean
- Static Factory
- <bean id=“beanId” class=“className" factory-method=" staticCreationMethod“>
- Instance Factory Method
- <bean id=“beanId” factory-bean=“existingBeanId" factory-method=“nonStaticCreationMethod">
- Beans may be singletons or “prototypes”
- Attribute singleton=“false” causes instantiation with each getBean() lookup
- Singleton is default
- XmlBeanFactory pre-instantiates singletons
- May be overridden on per-instance basis by lazy-init=“true”
- Beans may also be marked abstract, allowing reuse of attribute values through inheritance
Autowiring Properties :
- Beans may be auto-wired (rather than using <ref>)
- Per-bean attribute autowire
- Explicit settings override
- autowire=“name”
- Bean identifier matches property name
- autowire=“type”
- Type matches other defined bean
- autowire=”constructor”
- Match constructor argument types
- autowire=”autodetect”
- Attempt by constructor, otherwise “type”
ApplicationContext :
- Extends functionality of BeanFactory
- Pre-instantiates singleton beans
- Detects and registers BeanPostProcessors and BeanFactoryPostProcessors
- Supports nesting of contexts
- ApplicationListener and ApplicationEvents
- Initialized and closed predefined
- Custom may be created
- MessageSource provides i18n messaging
- <bean id=”messageSource” class=”...ResourceBundleMessageSource”/> Contains list of bundle base names.
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