Comprehensive Guide to Spring MVC, Spring Bean, and Spring Boot Annotations

1. Spring Web MVC Annotations

The @RequestMapping annotation maps HTTP requests to handler methods; it supports six attributes (value, method, params, header, consumes, produces) and can be applied at both class and method levels. Example usage:

@RequestMapping(value="/users", method=RequestMethod.GET, params="id")

Shortcut annotations such as @GetMapping, @PostMapping, @PutMapping, @DeleteMapping and @PatchMapping are equivalent to @RequestMapping with a specific HTTP method.

2. Spring Bean Annotations

Core component annotations include @Component, @Service, @Repository, and @Controller, which register classes as Spring beans. Scoping is controlled with @Scope, supporting singleton, prototype, request, session, etc. @Scope(value = ConfigurableBeanFactory.SCOPE_PROTOTYPE) Dependency injection is performed with @Autowired (field, setter, or constructor), optionally qualified by @Qualifier or prioritized with @Primary. Lifecycle callbacks use @PostConstruct and @PreDestroy.

3. Container‑Configuration Annotations

Exception handling and model binding are simplified with @ControllerAdvice, @ExceptionHandler, @ModelAttribute, and @ResponseBody. Cross‑origin support is added via @CrossOrigin, and data binding customization uses @InitBinder.

4. Spring Boot Annotations

The meta‑annotation @SpringBootApplication combines @Configuration, @EnableAutoConfiguration, and @ComponentScan, enabling rapid application setup.

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Conditional bean creation can be controlled with annotations such as @ConditionalOnClass, @ConditionalOnMissingBean, @ConditionalOnProperty, and others, allowing fine‑grained configuration based on classpath, bean presence, or property values.

Overall, the article serves as a reference sheet for developers to understand and correctly apply the wide range of Spring and Spring Boot annotations in modern Java backend projects.