[Spring] Spring IoC Contrainer & Spring Configurations

Spring IoC Container

• The Spring IoC container is at the core of the Spring Framework
• Uses IoC to manage components that make up an application
• Components are expressed as regular Java Beans
• Container manages the relationships between beans and is responsible for configuring them
• Manages the lifecycle of the beans

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Spring Configurations

• Ref-Bean
•  <ref bean> element

• used to set properties that reference other beans
• defined as sub-element of <property> element
• e.g.
•  
• Inner Bean
• A <bean/> element inside the <property/> or <constructor-arg/> elements
• Inner beans do not have an id attribute.

• Inner beans in constructor injection

• Compound Properties

•   "country" bean must have a "person" nested bean, which in turn has an "age" property.
• Equivalent to countryBean.getPerson().setAge(23)