Validation in service layer (SpringBoot) - java

I have a DTO which is validated at Controller layer with a mix of BeanValidation (javax.validation) and a custom Validator (org.springframework.validation.Validator). This way I can check if the input provided is valid and then convert the DTO in an entity and forward it to the Service layer.
#Data
public class UserDTO {
#NotBlank
#Size(max = 25)
private String name;
#NotNull
private Date birthday;
#NotNull
private Date startDate;
private Date endDate;
private Long count;
}
public class UserDTOValidator implements Validator {
private static final String START_DATE= "startDate";
private static final String END_DATE= "endDate";
private static final String COUNT= "count";
#Override
public boolean supports(Class<?> clazz) {
return UserDTO.class.isAssignableFrom(clazz);
}
#Override
public void validate(Object target, Errors errors) {
UserDTO vm = (UserDTO) target;
if (vm.getEndDate() != null) {
if (vm.getStartDate().after(vm.getEndDate())) {
errors.rejectValue(START_DATE, ErrorCode.ILLEGAL_ARGUMENT.toString(), ErrorCode.ILLEGAL_ARGUMENT.description());
}
if (vm.getEndDate().equals(vm.getStartDate()) || vm.getEndDate().before(vm.getStartDate())) {
errors.rejectValue(END_DATE, ErrorCode.ILLEGAL_ARGUMENT.toString(), ErrorCode.ILLEGAL_ARGUMENT.description());
}
}
if (vm.getCount() < 1) {
errors.rejectValue(COUNT, ErrorCode.ILLEGAL_ARGUMENT.toString(), ErrorCode.ILLEGAL_ARGUMENT.description());
}
.....
}
}
public class UserController {
#InitBinder
protected void initBinder(WebDataBinder binder) {
binder.addValidators(new UserDTOValidator());
}
#PostMapping()
public ResponseEntity<UserDTO> create(#RequestBody #Valid UserDTO userDTO) {
.....
}
.....
}
Then there is the business logic validation. For example: the #Entity User's startDate must be after some event occurred and the count has to be greater than some X if the last created User's birthDay is in Summer, in other case, the entity should be discarded by the User service.
#Service
#Transactional
public class UserServiceImpl implements UserService {
#Autowired
private UserRepository userRepository;
#Autowired
private SomeEventService someEventService ;
#Override
public User create(User entity) {
String error = this.validateUser(entity);
if (StringUtils.isNotBlank(error)) {
throw new ValidationException(error);
}
return this.userRepository.save(entity);
}
....
private String validateUser(User entity) {
SomeEvent someEvent = this.someEventService.get(entity.getName());
if (entity.getStartDate().before(someEvent.getDate())) {
return "startDate";
}
User lastUser = this.userRepository.findLast();
....
}
}
However I feel like this is not the best approach to handle business logic validation. What should I do? ConstraintValidator/HibernateValidator/JPA Event listeners? Can they work at #Entity class level or I have to create X of them for each different field check? How do you guys do it in a real production application?

In my suggestion,
Use classic field level validation by #Valid
sample
void myservicemethod(#Valid UserDTO user)
For custom business level validation in entity level, create validate method in DTO itself
sample
class UserDTO {
//fields and getter setter
void validate() throws ValidationException {
//your entity level business logic
}
}
This strategy will help to keep entity specific validation logic will be kept within the entity
If still you have validation logic that requires some other service call, then create custom validation annotation with custom ConstraintValidator (eg. question on stackoverflow). In this case, my preference will be to invoke UserDTO.validate() from this custom validator in spiote of calling from service
This will help to keep your validation logic separated from service layer and also portable and modular

Related

Is there a way to selectively disable auditing for entity modifications in tests?

I have several entities that need to be audited. Auditing is implemented by using the following JPA event listener.
public class AuditListener {
#PrePersist
#Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW)
public void setCreatedOn(Auditable auditable) {
User currentUser = getCurrentUser();
Long entityId = auditable.getId();
Audit audit;
if (isNull(entityId)) {
audit = getCreatedOnAudit(currentUser);
} else {
audit = getUpdatedOnAudit(auditable, currentUser);
}
auditable.setAudit(audit);
}
#PreUpdate
#Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW)
public void setUpdatedOn(Auditable auditable) {
User currentUser = getCurrentUser();
auditable.setAudit(getUpdatedOnAudit(auditable, currentUser));
}
private Audit getCreatedOnAudit(User currentUser) {
return Audit.builder()
.userCreate(currentUser)
.dateCreate(now())
.build();
}
private Audit getUpdatedOnAudit(Auditable auditable, User currentUser) {
AuditService auditService = BeanUtils.getBean(AuditService.class);
Audit audit = auditService.getAudit(auditable.getClass().getName(), auditable.getId());
audit.setUserUpdate(currentUser);
audit.setDateUpdate(now());
return audit;
}
private User getCurrentUser() {
String userName = "admin";
UserService userService = BeanUtils.getBean(UserService.class);
Authentication auth = SecurityContextHolder.getContext().getAuthentication();
if (nonNull(auth)) {
Object principal = auth.getPrincipal();
if (principal instanceof UserDetails) {
userName = ((UserDetails)principal).getUsername();
}
}
return userService.findByLogin(userName);
}
}
In a test environment(unit tests, e2e) for some tests I want to be able to manually set the audit.
Is that possible? I have previously tried to solve this problem with Spring AOP but unfortunately without success. I think, that Spring AOP could allow selectively set the audit by using various combinations in pointcuts:
Audit for cascade saving by using Spring AOP
Why aspect not triggered for owner side in OneToOne relationship?
Is there a way to selectively set auditing by using JPA features?
Solved as was suggested by Naros.
The logic for pre-persist and pre-update is moved to a separate injectable component, and AuditListener delegates execution to different implementations of this component, depending of the current active profile.
For Spring Boot 2.1.0:
Common interface:
public interface AuditManager {
void performPrePersistLogic(Auditable auditable);
void performPreUpdateLogic(Auditable auditable);
}
Listener for JPA callbacks:
#Component
#RequiredArgsConstructor
public class AuditListener {
private final AuditManager auditManager;
#PrePersist
public void setCreatedOn(Auditable auditable) {
auditManager.performPrePersistLogic(auditable);
}
#PreUpdate
public void setUpdatedOn(Auditable auditable) {
auditManager.performPreUpdateLogic(auditable);
}
}
Implementations of the common interface, for test environment and local environment:
#RequiredArgsConstructor
public class AuditChanger implements AuditManager {
private final UserService userService;
private final AuditService auditService;
#Override
#Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW)
public void performPrePersistLogic(Auditable auditable) {
// logic here
}
#Override
#Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW)
public void performPreUpdateLogic(Auditable auditable) {
// logic here
}
}
public class AuditNoChanger implements AuditManager {
// mostly similar
...
Configuration that allows Spring perform injection of different implementation depending of the currently active profile:
#Configuration
public class AuditConfig {
#Bean
#Profile("e2e")
public AuditManager getAuditNoChanger() {
return new AuditNoChanger();
}
#Bean
#Profile("local")
public AuditManager getAuditChanger(AuditService auditService,
CurrentUserService currentUserService) {
return new AuditChanger(auditService, currentUserService);
}
}
Also need to allow beans overriding in *.yml file:
spring:
main:
allow-bean-definition-overriding: true

Spring validator class does not validate the Dto data

I am implementing a microservice which has only to validate Transaction
from the request body, and if it is valid, send it to the next microservice. I have implemented the Validator, but it does not seem to work
Transaction DTO:
public class Transaction {
private TransactionType transactionType;
private String iban;
private String CNP;
private String name;
private String description;
private Float sum;
...
}
The Validator:
#Component()
public class TransactionValidation implements Validator {
#Override
public boolean supports(Class<?> aClass) {
return Transaction.class.equals(aClass);
}
#Override
public void validate(Object object, Errors errors) {
Transaction transaction = (Transaction) object;
if(!isValidCnp(transaction.getCNP())){
errors.rejectValue("CNP", "CNP validation error");
}
if(!isValidIban(transaction.getIban())){
errors.rejectValue("IBAN", "IBAN validation error");
}
if(isInputStringEmpty(transaction.getName())){
errors.rejectValue("name", "Name validation error");
}
}
...
}
The Controller does nothing but simply returns the transaction it receives:
#PostMapping()
public Transaction validateTransaction(#RequestBody #Valid Transaction transaction){
return transaction;
}
But it does not seem to work, it seems that the app does not use the Validator implemented above. Why? Do I have to register my validator anywhere?
I believe the #Valid annotation works on JSR-303 validation spec with annotations in your DTO. You have 2 options
public class Transaction {
#NonNull
#NotEmpty
#NumericIbanConstriant
private String iban;
}
#Constraint(validatedBy = NumericIbanConstriantValidator.class)
public #interface NumericIbanConstriant {
}
public NumericIbanConstriantValidator implements ConstraintValidator<NumericIbanConstraint, String> {
// validation logic for iban string being numeric perhaps?
}
OR in your controller directly autowire the TransactionValidation and call "validate" passing in Transaction, and Errors object
#PostMapping()
public Transaction validateTransaction(#RequestBody Transaction transaction, Errors errors){
transactionValidation.validate(transaction, errors);
return transaction;
}

Spring Data REST JPA: Integrate automatic CRUD operations with manual controller

I'm using Spring Data REST JPA to build a RESTful web service. So far, Spring is auto-generating all the responses for all the possible methods and for listing all the resources available and even for searches over them:
#RepositoryRestResource(collectionResourceRel = "scans", path = "scans")
public interface ScanRepository extends PagingAndSortingRepository<Scan, Long> {
List<Scan> findByProjectId(#Param("pid") String pid);
}
Now I would like to modify what is returned "only" to POST requests while leaving intact the support to all the others.
I thought I'd create a controller for this purpose like the following:
#Controller
public class ScanController {
#RequestMapping(value = "/scans", method = POST, produces = {MediaType.APPLICATION_JSON_VALUE})
public #ResponseBody Result parseScan(#RequestParam String projectId, #RequestParam String tool) {
return null;
}
However when I do this, the JPA-data auto-generated responses for all the other methods and searches etc. ceases to exist. For instance, I get "Method not allowed" if I forward a GET request.
Besides, how could I access a JSON payload from the controller?
UPDATE
Now only one of the exposed resource does back to the default methods for requests not manually handled in my own controller. However I have no idea why it does and why this doesn't happen for any of the other resources.*
Despite they all only differ in their entity's attributes.
The following particular resource is the one that does back to the default request handlers for anything that is not POST scan/ or GET /scan/// which I declared in the controller:
#Controller
public class ScanController {
#Autowired
private ScanService scanService;
#RequestMapping(
value = "/scan",
method = POST,
consumes = MediaType.APPLICATION_JSON_VALUE,
produces = {MediaType.APPLICATION_JSON_VALUE})
public #ResponseBody
Scan parseScan(#RequestBody Scan rbody) {
<...do something...>
}
#RequestMapping(value = "/scans/{id}/{totvuln}/{nth}", method = RequestMethod.GET,
produces = {MediaType.APPLICATION_JSON_VALUE})
public #ResponseBody
Scan getScan(#PathVariable String id, #PathVariable int totvuln, #PathVariable int nth) throws ScanNotFound {
<...do something...>
}
It has the following repository interface:
public interface ScanRepository extends PagingAndSortingRepository<Scan, Long> {}
and the following service:
#Service
public class ScanServiceImpl implements ScanService {
#Resource
private ScanRepository scanRepository;
#Resource
private ResultRepository resultRepository;
#Override
#Transactional
public Scan create(Scan shop) {
<some code>
}
#Override
#Transactional
public Scan findById(long id) {
<some code>
}
#Override
#Transactional(rollbackFor = ScanNotFound.class)
public Scan delete(long id) throws ScanNotFound {
<some code>
}
#Override
#Transactional
public List<Scan> findAll() {
<some code>
}
#Override
#Transactional(rollbackFor = ScanNotFound.class)
public Scan update(Scan scan) throws ScanNotFound {
<some code>
}
}
and the resource itself has the following attributes:
#Entity
public class Scan {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private Long projectId;
#OneToMany
private Collection<Result> result;
private int totV;
<getters and setters>
}
While the following semi-identical resource "Rules" does not back to any of the default request handlers. It returns "Method not Allowed" for anything different from POST /rule:
#Controller
public class RulesController {
#Autowired
private RulesService rService;
#Resource
private ScanRepository scanRepository;
#RequestMapping(
value = "/rule",
method = POST,
consumes = MediaType.APPLICATION_JSON_VALUE,
produces = {MediaType.APPLICATION_JSON_VALUE})
public #ResponseBody
Rules generateRules(#RequestBody Scan rbody) throws Exception {
<do something>
}
}
It has the same repository interface:
public interface RulesRepository extends PagingAndSortingRepository<Rules, Long> {}
and also the same service implementation:
#Service
public class RulesServiceImpl implements RulesService {
#Resource
private RulesRepository rRepository;
#Resource
private ResultRepository resultRepository;
#Override
#Transactional
public Rules create(Rules shop) {
<do something>
}
#Override
#Transactional
public Rules findById(long id) {
<do something>
}
#Override
#Transactional(rollbackFor = RulesNotFound.class)
public Rules delete(long id) throws RulesNotFound {
<do something>
}
#Override
#Transactional
public List<Rules> findAll() {
<do something>
}
#Override
#Transactional
public Rules findByScanId(long id) throws RulesNotFound {
<do something>
}
#Override
#Transactional(rollbackFor = RulesNotFound.class)
public Rules update(Rules scan) throws RulesNotFound {
<do something>
}
}
and the resource Rules itself has the following attributes:
#Entity
public class Rules {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#OneToOne
private Scan scan;
#OneToMany
private Collection<Result> result;
private String rules;
<getters and setters>
}
Why isn't Spring exposing the default request handlers also for "Rules" for any request that hasn't been specified manually in my controller class?
I would truly appreciate if you could point out why. Thank you so much!
I've figured out how to access a JSON payload from the controller:
#RequestMapping(
value = "/scan",
method = POST,
consumes = MediaType.APPLICATION_JSON_VALUE,
produces = {MediaType.APPLICATION_JSON_VALUE})
public #ResponseBody
Scan parseScan(#RequestBody Scan rbody) {
Scan scan = new Scan();
scan.setProjectId(rbody.getProjectId());
scan.setTool(rbody.getTool());
return scan;
}
Also I've realised the automatic CRUD operations were actually being already supported for every request not handled by my own controller: I was just requesting the wrong URL.
I got the list of correct URLs to use by requesting "curl http://localhost:8080"
However, the preferred URL for any of the auto-generated operations can be set with
#RepositoryRestResource(collectionResourceRel = pref_URL_suffix, path = pref_URL_suffix)
^^somehow during all the changes I tried, that line above went missing.

Java class inheritance/interface implementation principle

I am not sure of using inheritance / interface implementation in particular situation.
In my simple Spring MVC application I have #Entity class TennisPlayer, which is inherited from abstract class Player (TennisPlayer adds some attributes).
Also I have class TennisPlayerForm, which is inherited from abstract class PlayerForm (TennisPlayerForm adds some attributes again).
User fills the form about tennis player in .jsp page and TennisPlayerForm object is used to represent filled values and then on the basis of this object is created TennisPlayer object and saved into database.
Creation of TennisPlayer object is responsibility of class TennisPlayerDbService. This class is implementation of interface PlayerService.
I have following #Controller, which handles requests:
#Controller
public class NewPlayerController {
#Resource(name="tennisPlayerService")
private PlayerService playerService;
//omitted RequestMethod.GET handler method
#RequestMapping(value = "/newplayer", method = RequestMethod.POST)
public String newplayer(Locale locale, #ModelAttribute("tennisPlayerForm") #Valid TennisPlayerForm tennisPlayerForm,
BindingResult result, RedirectAttributes redirectAttributes) {
playerService.createPlayer(tennisPlayerForm);
return "redirect:/allplayers";
}
}
Part of my source code looks like this:
public interface PlayerService {
public void createPlayer(PlayerForm playerForm);
}
#Service(value="tennisPlayerService")
public class TennisPlayerDbService implements PlayerService {
private TennisPlayerDAO dao;
#Autowired
public void setDao(TennisPlayerDAO dao) {
this.dao = dao;
}
#Override
public void createPlayer(PlayerForm playerForm) {
TennisPlayerForm tennisPlayerForm = null;
if (playerForm instanceof TennisPlayerForm) {
tennisPlayerForm = (TennisPlayerForm) playerForm;
}
else {
throw new IllegalArgumentException("Must be of type TennisPlayerForm.");
}
TennisPlayer player = new TennisPlayer();
player.setName(tennisPlayerForm.getName());
player.setSurname(tennisPlayerForm.getSurname());
player.setAge(tennisPlayerForm.getAge());
player.setRacket(tennisPlayerForm.getRacket());
player.setRanking(tennisPlayerForm.getRanking());
player.setSponsor(tennisPlayerForm.getSponsor());
player.setCoach(tennisPlayerForm.getCoach());
player.setClub(tennisPlayerForm.getClub());
dao.saveAndFlush(player);
}
}
Is it justified to use inheritance and interface implementations like this in this situation, when concrete implementation of PlayerService (TennisPlayerDbService) expects instance of particular class, although these potential classes have common parent?
Finally I solved my problem according to your comments and answers.
I deleted PlayerForm abstract class, TennisPlayerForm and mixed javax.validation and javax.persistence annotations in #Entity classes Player and Tennis Player.
Previously mentioned code now looks like this:
#Controller
public class NewPlayerController {
#Resource(name="tennisPlayerService")
private PlayerService<TennisPlayer> playerService;
//omitted RequestMethod.GET handler method
#RequestMapping(value = "/newplayer", method = RequestMethod.POST)
public String newplayer(Locale locale, #ModelAttribute("tennisPlayer") #Valid TennisPlayer tennisPlayer,
BindingResult result, RedirectAttributes redirectAttributes) {
if(result.hasErrors()) {
return "newplayer";
}
playerService.createPlayer(tennisPlayer);
MessageUtil.flash(locale, redirectAttributes, "success", "signup.success");
return "redirect:/allplayers";
}
}
public interface PlayerService<T extends Player> {
public void createPlayer(T player);
public List<T> getAllPlayers();
}
#Service(value="tennisPlayerService")
public class TennisPlayerDbService implements PlayerService<TennisPlayer> {
private TennisPlayerDAO dao;
#Autowired
public void setDao(TennisPlayerDAO dao) {
this.dao = dao;
}
#Override
public void createPlayer(TennisPlayer player) {
dao.saveAndFlush(player);
}
#Override
public List<TennisPlayer> getAllPlayers() {
return dao.findAll();
}
}
Normally your service does not need to know you are working with a form. Your form is purely created to be the model in the model-view-controller architecture of your webpage. (your jsp being the view and your controller being the c-part)
Are you also planning on using other types of players than a TennisPlayer? If not it all seems like premature optimisation and you should keep it as simple as possible.

Spring MVC validator annotation + custom validation

I'm working on spring mvc application, where I should aplly validation based on Spring MVC validator. I first step for that I added annotation for class and setup controller and it works fine. And now I need to implement custom validator for perform complex logic, but i want to use existing annotation and just add additional checking.
My User class:
public class User
{
#NotEmpty
private String name;
#NotEmpty
private String login; // should be unique
}
My validator:
#Component
public class UserValidator implements Validator
{
#Autowired
private UserDAO userDAO;
#Override
public boolean supports(Class<?> clazz)
{
return User.class.equals(clazz) || UsersForm.class.equals(clazz);
}
#Override
public void validate(Object target, Errors errors)
{
/*
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "NotEmpty.user");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "login", "NotEmpty.user");
*/
User user = (User) target;
if (userDAO.getUserByLogin(user.getLogin()) != null) {
errors.rejectValue("login", "NonUniq.user");
}
}
}
My controller:
#Controller
public class UserController
{
#Autowired
private UserValidator validator;
#InitBinder
protected void initBinder(final WebDataBinder binder)
{
binder.setValidator(validator);
}
#RequestMapping(value = "/save")
public ModelAndView save(#Valid #ModelAttribute("user") final User user,
BindingResult result) throws Exception
{
if (result.hasErrors())
{
// handle error
} else
{
//save user
}
}
}
So, Is it possible to use custom validator and annotation together? And if yes how?
I know this is a kind of old question but, for googlers...
you should use addValidators instead of setValidator. Like following:
#InitBinder
protected void initBinder(final WebDataBinder binder) {
binder.addValidators(yourCustomValidator, anotherValidatorOfYours);
}
PS: addValidators accepts multiple parameters (ellipsis)
if you checkout the source of org.springframework.validation.DataBinder you will see:
public class DataBinder implements PropertyEditorRegistry, TypeConverter {
....
public void setValidator(Validator validator) {
assertValidators(validator);
this.validators.clear();
this.validators.add(validator);
}
public void addValidators(Validator... validators) {
assertValidators(validators);
this.validators.addAll(Arrays.asList(validators));
}
....
}
as you see setValidator clears existing (default) validator so #Valid annotation won't work as expected.
If I correctly understand your problem, as soon as you use you custom validator, default validation for #NotEmpty annotation no longer occurs. That is common when using spring : if you override a functionnality given by default, you have to call it explicitely.
You have to generate a LocalValidatorFactoryBean and inject it with your message source (if any). Then you inject that basic validator in you custom validator and delegate annotation validation to it.
Using java configuration it could look like :
#Configuration
public class ValidatorConfig {
#Autowired
private MessageSource messageSource;
#Bean
public Validator basicValidator() {
LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
validator.setValidationMessageSource(messageSource);
return validator;
}
}
Then you modify UserValidator to use it :
#Component
public class UserValidator implements Validator
{
#Autowired
#Qualifier("basicValidator")
private Validator basicValidator;
#Autowired
private UserDAO userDAO;
// ...
#Override
public void validate(Object target, Errors errors)
{
basicValidator.validate(target, errors);
// eventually stop if any errors
// if (errors.hasErrors()) { return; }
User user = (User) target;
if (userDAO.getUserByLogin(user.getLogin()) != null) {
errors.rejectValue("login", "NonUniq.user");
}
}
}
Well for me you have to delete the
#InitBinder
protected void initBinder(final WebDataBinder binder)
{
binder.setValidator(validator);
}
Leave the
#Valid #ModelAttribute("user") final User user,
BindingResult result
And after in the function make
validator.validate(user,result)
This way you will use the validation basic with the #Valid and after you will put make the more complex validation.
Because with the initBinder you are setting the validation with your complex logic and putting a way the basic logic.
Maybe is wrong, i use always the #Valid without any validator.

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