Spring
Framework for building enterprise-level applications in Java.
Attribute Oriented Programming (@OP) / Spring Annotations
Stereotype Annotations
Define purpose of a class.
Although, these are not just indicators. These annotations also trigger additional behavior and configurations. These additional behaviors and configurations are based on common aaplication patterns.
@Component
Marks the class as a general-purpose bean (Spring-managed component).
- Main influence here is to make the class eligible for component scanning. This adds the class to application context.
- Also allows using
@Autowiredfor Dependency Injection.
@Service
Marks the class as Service.
Transaction management can automatically be applied to methods in service class.
@Repository
Marks a class as Repository.
Enables DAO and persistence related exceptions under Spring's DataAccessException hierarchy.
@Controller
Makes Controllers capable of handling HTTP requests.
Works along with @RequestMapping annotation to map HTTP handler methods.
@RestController
@Controller + @ResponseBody
Special type of Controller, which combines @Controller and @RequestBody.
=> Return values of handler methods are automatically serialized into JSON or XML and returned as response.
NOTE: For the below annotations to work, it is important that the class is annotated with
@Controlleror@RESTController. Otherwise, it won't work, there won't be any errors, it simply wouldn't work.
Multi-value/array configuration
You can provide multiple values to annotation attributes in form of an array.
@RequestMapping(value = "/", method = { RequestMethod.GET, RequestMethod.POST })
References
Children