REST API Development

@RestController
@RequestMapping("/api/donations")
public class DonationController {

    @GetMapping("/{id}")
    public ResponseEntity<DonationResponse> getDonation(@PathVariable Long id) {
        // => Auto-serialized to JSON by Jackson
        // => Content-Type: application/json (auto-negotiated)
        DonationResponse response = donationService.findById(id);
        return ResponseEntity.ok(response);
    }

    @PostMapping
    public ResponseEntity<DonationResponse> createDonation(
            @RequestBody @Valid DonationRequest request) {
        // => @Valid triggers Bean Validation (auto-configured)
        // => Jackson deserializes JSON to DonationRequest
        DonationResponse response = donationService.create(request);
        return ResponseEntity.status(HttpStatus.CREATED).body(response);
    }

    @GetMapping
    public Page<DonationResponse> listDonations(
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "20") int size) {
        // => Pagination auto-configured with Spring Data
        Pageable pageable = PageRequest.of(page, size);
        return donationService.findAll(pageable);
    }
}

spring:
  jackson:
    serialization:
      write-dates-as-timestamps: false # => ISO 8601 dates
    default-property-inclusion: non_null # => Exclude null fields
  mvc:
    throw-exception-if-no-handler-found: true
    # => 404 exceptions for missing endpoints