Autowiring does not work inside custom constraint validator using Spring-Test-MVC

[Darren Carter]

Hi Eveyone,

I have posted this in the Spring forums but have not had a reply. Can anyone help with this please..?

I have an issue with autowiring inside a custom constraint validator when running an integration test using spring-test-mvc. The service I require is null.

However when I run the web app, its is auotwired correctly.

Custom Constraint Validator (Booking Service is null!)

public class CheckAvailabilityValidator implements ConstraintValidator<CheckAvailability, Booking> {

	private DateTimeFormatter formatter;
	private int maxNumberOfBookings = 2;
	
	@Autowired
	private BookingService bookingService;

	public void initialize(CheckAvailability constraintAnnotation) {
		formatter = DateTimeFormat.forPattern("dd/MM/yyyy");
	}

	public boolean isValid(Booking booking, ConstraintValidatorContext constraintContext) {
		
		if (booking.getArrivalDate() == null || booking.getDepartureDate() == null) {
			return false;
		}

		DateTime arrivalDate = formatter.parseDateTime(booking.getArrivalDate());
		DateTime departureDate = formatter.parseDateTime(booking.getDepartureDate());
		
		if (bookingService.findBookingsByDateRange(arrivalDate,departureDate).size() > maxNumberOfBookings) {
			return false;
		} else {
			return true;
		}
	}

}

Annotation

@Target({ TYPE, ANNOTATION_TYPE })
@Retention(RUNTIME)
@Constraint(validatedBy = CheckAvailabilityValidator.class)
@Documented
public @interface CheckAvailability {

    String message() default "{we.do.not.have.availability}";
    
    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

}

Service

@Service
public class BookingService implements IBookingService{
	
        @Autowired
        private BookingDao bookingDao;
	
	private static Logger logger = LoggerFactory.getLogger(BookingService.class);
	
	@Override
	public List<Booking> findBookingsByDateRange(DateTime from, DateTime to) {
		return bookingDao.findBookingsByDateRange(from, to);
               
	}
	
}

Unit Test

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {BookingControllerConfig.class})
public class BookingControllerTest {

        @Autowired
	private BookingController bookingController;
	
	private List<Booking> bookingList = new ArrayList<Booking>();

        .....
	
        @Test
	public void testPostBookingDetails() throws Exception {


		
         standaloneSetup(bookingController).build().perform(post("/booking_details")
				.param("arrivalDate", "01/01/2013")
				.param("departureDate", "09/01/2013")
				.param("accomendationType", "Suite")
				.param("numberOfAdults", "2")
				.param("numberOfChildren", "2"))		
			.andDo(print())
			.andExpect(status().isOk());
	}
...

}

Config

@Configuration
public class BookingControllerConfig {
	
	@Bean
	public BookingController bookingController() {
		return new BookingController();
	}
	
	@Bean
	public BookingService bookingService() {
		return Mockito.mock(BookingService.class);
	}

.....

}

Controller

@Controller
public class BookingController {

   ...

      @RequestMapping(value = "/booking_details", method = RequestMethod.POST)
      public ModelAndView showBookingDetails(@Validated Booking booking, BindingResult bindingResult, ContactDetails  
                                                               contactDetails, HttpServletResponse response) throws IOException {
      ...
      }
  ...
}

[Darren Carter]

Hi Everyone,

With Thanks to Rossen Stoyanchev I have this working.

In short the problem is to do with standloneSetup with does not load spring configuration.

One option is to create a LocalValidatorFactoryBean configured with a SpringConstraintValidatorFactory and plug it into the standaloneSetup builder.

However I decided to migrate from spring-test-mvc to spring-test in 3.2.

All that was required was to annotate my test class with @WebAppConfiguration, load in my spring configuration files with @ContextConfiguration and then @Autowired WebApplicationContext

Example

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(value ={
		"file:src/main/webapp/WEB-INF/spring/appServlet/servlet-context.xml",
		"classpath:/META-INF/config/service-context.xml ",
		"classpath:/META-INF/config/persistence-context.xml",
		"classpath:/META-INF/config/dataSource-context.xml"
})

public class BookingControllerAvailabilityTestRefactor {
	
	@Autowired
	private BookingController bookingController;
	private String arrivalDate;
	private String departureDate;
	private static String dateFormat = "dd/MM/yyyy";
	
	@Autowired
	private WebApplicationContext wac;
	private MockMvc mvc;
	
	@Before
	public void setup() {
		arrivalDate= DateTime.now().plusDays(1).toString(dateFormat);
		departureDate= DateTime.now().plusDays(5).toString(dateFormat);
		this.mvc = webAppContextSetup(this.wac).build();
	}
	
	@Test
	public void testPostBookingDetails() throws Exception {
	    this.mvc.perform(post("/booking_details")
	    		.param("arrivalDate", this.arrivalDate)
				.param("departureDate", this.departureDate)
				.param("accomendationType", "Suite")
				.param("numberOfAdults", "2")
				.param("numberOfChildren", "2"))
			.andDo(print())
			.andExpect(status().isOk());
	        
	  }
	
		
}

I can now @Autowire services in my custom jsr annotation validator.

Hope this helps others

Regards
Darren C.

[Abhishekrvce Kumar]

We also faced the similar problem where @Autowiring was failing (not initialised) in ConstrainValidator Class. Our ConstraintValidator Implemented class was using a value which supposed to be read from the `application.yml` file.  Below solution helped us as this is using a pure spring scope. Hope this helps, with proper SpringJunit4ClassRunner.

    import org.springframework.test.context.web.WebAppConfiguration;
    import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
    import org.springframework.validation.beanvalidation.SpringConstraintValidatorFactory;
    import org.springframework.web.context.WebApplicationContext;
    
    @WebAppConfiguration
    @ContextConfiguration(classes = {ApplicationConfig.class})
    @RunWith(SpringJUnit4ClassRunner.class)
    @TestPropertySource(properties = {
            "spring.someConfigValue.InApplicationYaml=Value1",
    })
    public class MyTest {
    
    	@Autowired
    	private WebApplicationContext webApplicationContext;
    
    	LocalValidatorFactoryBean validator;
    
    	@Before
    	public void setup() {
    
    		SpringConstraintValidatorFactory springConstraintValidatorFactory
    		            = new SpringConstraintValidatorFactory(webApplicationContext.getAutowireCapableBeanFactory());
    		    validator = new LocalValidatorFactoryBean();
    		    validator.setConstraintValidatorFactory(springConstraintValidatorFactory);
    		    validator.setApplicationContext(webApplicationContext);
    		    validator.afterPropertiesSet();
    	}
    
    	@Test
    		public void should_have_no_violations_for_all_valid_fields() {
    
    		Set<ConstraintViolation<PojoClassWhichHaveConstraintValidationAnnotation>> violations = validator.validate(pojoClassObjectWhichHaveConstraintValidationAnnotation);
    
    		assertTrue(violations.isEmpty());
    	}
    
    }
    
    
    @Configuration
    public class ApplicationConfig {
    
        @Value("${spring.someConfigValue.InApplicationYaml=Value1}")
        public String configValueToBeReadFromApplicationYamlFile;
    
    }

[Georgy Louis]

Think about it. There should have been no issue with using @Autowired inside a Constraint validator class. This means that something is wrong.

This issue has been reported on various platform and I have seen some workaround. But I wanted to know how to solve it directly.

Here is what I found.
The problem was the incorrect use of the of class being validated. You may notice that the validation is happening twice. the first time it should work but the second time you got @Autowired object is null.

The problem was that the entity or the class being validated was being used twice in the controller. For example, you may want validate the entity class and try to save it at the same time in the same method in the controller method. When you try to save the entity, it will try to validate the object again and this time the @Autowired object will be null.

Here is what you can do for this scenario

You can use create a dto class of the entity class(meaning that the entity and the dto class will have the same field). Relocate the annotation validation from the entity class to the dto class.Then copy the properties of the entity class unto your your entity class and save your entity. This way the validation will happen once and the null error message should go away. Your scenario may be different but the approach should be the same.

Below is an example of code that works

[Georgy Louis]

Think about it[/b]. There should have been no issue with using @Autowired inside a Constraint validator class. This means that something is wrong.

This issue has been reported on various platform and I have seen some workaround. But I wanted to know how to solve it directly.

Here is what I found.
The problem was the incorrect use of the of class being validated. You may notice that the validation is happening twice. the first time it should work but the second time you got @Autowired object is null.

The problem was that the entity or the class being validated was being used twice in the controller. For example, you may want validate the entity class and try to save it at the same time in the same method in the controller method. When you try to save the entity, it will try to validate the object again and this time the @Autowired object will be null.

Here is what you can do for this scenario

You can use create a dto class of the entity class(meaning that the entity and the dto class will have the same field). Relocate the annotation validation from the entity class to the dto class.Then copy the properties of the entity class unto your your entity class and save your entity. This way the validation will happen once and the null error message should go away. Your scenario may be different but the approach should be the same.


Below is an example of code that works

public ResponseEntity<InstitutionModel> create(@Valid @RequestBody InstitutionDto institutiondto) {
		Institution institution = new Institution();
		BeanUtils.copyProperties(institutiondto, institution);
		return Optional.of(this.institutionService.save(institution)).map(institutionModelAssembler::toModel)
				.map(ResponseEntity::ok).orElse(ResponseEntity.notFound().build());
	}