A Spring bean refers to an object that’s managed by the Spring Inversion of Control (IoC) container.
In order to set Spring Bean’s scope, we can use @Scope annotation or “scope” attribute in XML configuration files.
| Scope | Description |
|---|---|
| singleton | Scopes a single bean definition to a single object instance per Spring IoC container. Not Thread Safe. |
| prototype | Scopes a single bean definition to any number of object instances. |
| request | Scopes a single bean definition to the lifecycle of a single HTTP request; that is, each HTTP request has its own instance of a bean created off the back of a single bean definition. Only valid in the context of a web-aware Spring ApplicationContext. |
| session | Scopes a single bean definition to the lifecycle of an HTTP Session. Only valid in the context of a web-aware Spring ApplicationContext. |
| global session | Scopes a single bean definition to the lifecycle of a global HTTP Session. Typically only valid when used in a portlet context. Only valid in the context of a web-aware Spring ApplicationContext. |
The application context serves as a container into which Spring can inject beans.
Spring Boot extends the Spring framework by enabling the autoconfiguration of Spring beans, further simplifying development.
@SpringBootApplication is a compilation of the @Configuration, @EnableAutoConfiguration, and @ComponentScan annotations.