mchmielarz

try {
  database.start();
  fetchMeasurements(geoCoordinatesReader, airlyService, measurementsRepository);
} catch (SQLException exc) {
  log.error("Cannot start the database", exc);
}

mchmielarz

Try
  .run(database::start)
  .onSuccess(ignore -> log.info("Database started successfully"))
  .onFailure(exc -> log.error("Cannot start the database", exc))
  .andThen(
    () -> fetchMeasurements(geoCoordinatesReader, airlyService, measurementsRepository)
  );

mchmielarz

Try.of(
  () -> geoCoordinatesReader.fromCsvFile("./src/main/resources/cities.csv")
)
  .onSuccess(coords -> log.info("Coordinates read: {}", coords))
  .onFailure(exc -> log.error("Cannot read coordinates from a file", exc))
  .recover(FileNotFoundException.class, (exc) -> provideBackupCoordinates())
  .getOrElse(List.empty());

mchmielarz

private static List<GeoCoordinates> provideBackupCoordinates() {
 log.warn("Calling for backup data");
 return List.of(
   GeoCoordinates.builder()
     .city("Warszawa")
     .latitude("52.25")
     .longitude("21")
     .build()
 );
}

mchmielarz

Try.of(() -> Uri.create("http://airapi.airly.eu/v2/measurements/nearest/..."))
  .flatMap(this::callAirly)
  .map(responseBody -> new RawMeasurements(coordinates.city(), responseBody))
  .mapTry(this::parse);

mchmielarz

private Try<String> callAirly(URI airlyUri) {
  HttpRequest req = requestBuilder.uri(airlyUri).build();
  return Try
    .of(() -> httpClient.send(req, bodyHandler))
    .map(HttpResponse::body);
}

mchmielarz

Try.of(this::computation)
  .onFailure(exc -> log.error("Computation failed!", exc))
  .andThen(this::storeInDb)
  .onFailure(exc -> log.error("Storing in database failed!", exc))
  .andThen(this::sendEmail)
  .onFailure(exc -> log.error("Email sending failed!", exc))
  .onSuccess(value -> log.info("Value computed, stored in db and sent in email"));

mchmielarz

@Target({ ElementType.METHOD, ElementType.FIELD })
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = IbanValidator.class)
public @interface Iban {
  String message() default "{iban.constraint}";
  Class<?>[] groups() default {};
  Class<? extends Payload>[] payload() default {};
}

mchmielarz

@Slf4j
public class IbanValidator implements ConstraintValidator<Iban, String> {

  @Override
  public boolean isValid(String value, ConstraintValidatorContext context) {
   if (value == null) {
     return false;
   }

  return Try.of(() -> {

mchmielarz

BankAccount bankAccount = newBankAccount("invalid_iban", "invalid_bic", null);
final Set<ConstraintViolation<BankAccount>> constraints = 
  Validation.buildDefaultValidatorFactory().getValidator().validate(bankAccount);