Spring Boot: Why is an autowired object in Custom Validator class is null? - spring

Question

The following code yields null on the teamResource auto-wired object inside isValid() function:
#Component //I am not sure it is required he
public class TeamIdValidator implements ConstraintValidator<TeamIdConstraint, Integer> {
#Autowired private TeamResource teamResource;
public TeamIdValidator() {
}
#Override
public void initialize(TeamIdConstraint teamIdConstraint) {
// this.teamIdConstraint = teamIdConstraint;
}
#Override
public boolean isValid(Integer teamId, ConstraintValidatorContext cxt) {
int numOfAvailableTeams = teamResource.retrieveAllTeams().size(); //teamResource is null :(
return teamId < 0 || teamId >= numOfAvailableTeams;
}
}
TeamResource class:
#RestController
#CrossOrigin
public class TeamResource {
#Autowired private TeamRepository teamRepository;
public TeamResource() {
}
...
//mapping methods
}
And if it relevant...
#Documented
#Constraint(validatedBy = TeamIdValidator.class)
#Target({ ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER })
#Retention(RetentionPolicy.RUNTIME)
public #interface TeamIdConstraint {
String message() default "Invalid team id!";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
Why on earth teamResource is null?
It is not being explicitly initialized with new anywhere else.

Answer 1

Already mentioned in the comments but declare a a bean like this
#Configuration
public class ValidationConfig{
#Bean
public LocalValidatorFactoryBean validator() {
return new LocalValidatorFactoryBean();
}
#Bean
public MethodValidationPostProcessor methodValidationPostProcessor(Validator validator) {
MethodValidationPostProcessor methodValidationPostProcessor = new MethodValidationPostProcessor();
methodValidationPostProcessor.setValidator(validator);
return methodValidationPostProcessor;
}
}
Remove all the #autowired, prefer constructor injection. (check the internet why).
And then, it makes no sense to inject a RestContoller to validator.