How do you use OpenAPI?

OpenAPI in Java projects is typically used for automatic documentation generation and client SDKs, as well as for validating incoming requests. For example, using Swagger (OpenAPI) annotations in Spring Boot, you can describe a REST API, and then generate interactive documentation accessible via a URL.

Example of usage with Spring Boot and Springdoc OpenAPI:

@RestController
@RequestMapping("/api/users")
public class UserController {

    @Operation(summary = "Get user by ID")
    @GetMapping("/{id}")
    public User getUser(@PathVariable Long id) {
        // logic to get user
    }
}

This allows frontend developers and other services to easily understand and use the API, as well as simplifies testing and maintenance.