This post is about Parsing XML In Groovy Using Xmlslurper — covering REST API design and implementation patterns in Spring Boot applications.

Introduction to REST APIs

REST (Representational State Transfer) is the dominant architectural style for building web APIs today. A well-designed REST API is predictable, consistent, easily discoverable, and a pleasure to work with. Spring Boot makes it straightforward to build production-quality REST APIs with very little configuration.

Building a REST Controller

@RestController
@RequestMapping("/api/v1/users")
public class UserController {
    
    private final UserService userService;
    
    public UserController(UserService userService) {
        this.userService = userService;
    }
    
    @GetMapping
    public List<UserDto> getAllUsers() {
        return userService.findAll();
    }
    
    @GetMapping("/{id}")
    public ResponseEntity<UserDto> getUserById(@PathVariable Long id) {
        return userService.findById(id)
            .map(ResponseEntity::ok)
            .orElse(ResponseEntity.notFound().build());
    }
    
    @PostMapping
    @ResponseStatus(HttpStatus.CREATED)
    public UserDto createUser(@Valid @RequestBody CreateUserRequest request) {
        return userService.create(request);
    }
    
    @DeleteMapping("/{id}")
    @ResponseStatus(HttpStatus.NO_CONTENT)
    public void deleteUser(@PathVariable Long id) {
        userService.delete(id);
    }
}

HTTP Status Codes Best Practices

• 200 OK — Successful GET, PUT, PATCH
• 201 Created — Successful POST that creates a resource
• 204 No Content — Successful DELETE
• 400 Bad Request — Invalid input/validation error
• 401 Unauthorized — Authentication required
• 403 Forbidden — Authenticated but not authorized
• 404 Not Found — Resource not found
• 500 Internal Server Error — Unexpected server error

Summary

Parsing XML In Groovy Using Xmlslurper illustrates how Spring Boot's @RestController and related annotations make it remarkably easy to build robust, standards-compliant REST APIs. Following these patterns ensures your APIs are intuitive and maintainable.