Spring Annotations Cheat Sheet

Spring annotations are a powerful tool for developers who use the Spring Framework. Annotations are a way to add metadata to code, which can be used by the framework to configure and manage the application. Spring annotations provide a way to simplify the configuration of Spring applications, making it easier to write and maintain code.

This cheat sheet provides an extensive list of Spring annotations with their descriptions.

Core Annotations

Annotation	Description
@Autowired	Marks a constructor, field, or method as to be autowired by Spring’s dependency injection facilities.
@Component	Indicates that an annotated class is a “”component””. Such classes are considered as candidates for auto-detection when using annotation-based configuration and classpath scanning.
@Configuration	Indicates that a class declares one or more @Bean methods and may be processed by the Spring container to generate bean definitions and service requests for those beans at runtime.
@Controller	Indicates that an annotated class is a “”Controller”” (e.g. a web controller).
@Repository	Indicates that an annotated class is a “”Repository”” (e.g. a data access object).
@Service	Indicates that an annotated class is a “”Service”” (e.g. a business service).
@Scope	Specifies the scope of a bean.

Web Annotations

Annotation	Description
@ControllerAdvice	Marks a class as a global exception handler for all @RequestMapping methods.
@CrossOrigin	Configures cross-origin resource sharing (CORS) for a web application.
@RequestMapping	Maps HTTP requests to handler methods of a controller.
@RequestParam	Binds the value of a request parameter to a method parameter.
@ResponseBody	Indicates that a method return value should be bound to the web response body.
@RestController	A convenience annotation that combines @Controller and @ResponseBody.
@PathVariable	Binds a URI template variable to a method parameter.
@GetMapping	Shortcut for @RequestMapping(method = RequestMethod.GET).
@PostMapping	Shortcut for @RequestMapping(method = RequestMethod.POST).
@PutMapping	Shortcut for @RequestMapping(method = RequestMethod.PUT).
@DeleteMapping	Shortcut for @RequestMapping(method = RequestMethod.DELETE).

Data Annotations

Annotation	Description
@Transactional	Marks a method as transactional.
@Entity	Indicates that an annotated class is a JPA entity.
@Table	Specifies the primary table for the annotated entity.
@Column	Specifies the mapped column for a persistent property or field.
@Id	Specifies the primary key of an entity.
@GeneratedValue	Provides for the specification of generation strategies for the values of primary keys.
@ManyToOne	Defines a many-to-one relationship between two entities.
@OneToMany	Defines a one-to-many relationship between two entities.
@JoinColumn	Specifies a column for joining an entity association or element collection.

Security Annotations

Annotation	Description
@EnableWebSecurity	Enables Spring Security’s web security support and provides the Spring Security configuration.
@Secured	Defines a method-level security expression.
@PreAuthorize	Defines a method-level security expression that is evaluated before a method is invoked.
@PostAuthorize	Defines a method-level security expression that is evaluated after a method is invoked.
@RolesAllowed	Defines a list of roles that are allowed to access a method.
@AuthenticationPrincipal	Provides access to the currently authenticated user.

Test Annotations

Annotation	Description
@RunWith	Specifies the test runner to use.
@SpringBootTest	Loads the complete Spring application context for integration testing.
@WebMvcTest	Loads only the web layer of a Spring application context for testing controllers.
@DataJpaTest	Loads only the JPA layer of a Spring application context for testing repositories.
@MockBean	Creates a mock object for a bean in the Spring application context.
@Autowired	Injects a bean from the Spring application context into a test class.

Conclusion

This cheat sheet provides an extensive list of Spring annotations with their descriptions. It is a useful reference for developers who are working with Spring applications.

Reference:

https://docs.spring.io/spring-framework/docs/current/reference/html/