Spring Boot request body validation - spring-boot

Question

I am working on Spring REST API and have following controller:
#RestController
#RequestMapping(
value = "/api/Test",
produces = "application/json"
)
public class MyController {
#RequestMapping(method = RequestMethod.POST)
public Response serviceRequest(#Valid #RequestBody ServiceRequest myServiceRequest) {
....
}
}
ServiceRequest has following structure:
#Getter
#Setter
#AllArgsConstructor
#NoArgsConstructor
public class ServiceRequest {
#NotBlank
private LocalDate fromDate;
#NotBlank
private LocalDate toDate;
}
My task is to introduce validation based on combination of fromDate and toDate field's values: if time period between them is longer that 1 week then validation should fail.
What is the best way to archive this please?

Answer 1

You may create a custom constraint validator that will validate the required conditions before processing the request.
DatesDifference.java
#Constraint(validatedBy = DatesDifferenceValidator.class)
#Target(ElementType.TYPE)
#Retention(RetentionPolicy.RUNTIME)
public #interface DatesDifference {
String message() default "Dates difference is more than a week";
Class<?>[] groups() default { };
Class<? extends Payload>[] payload() default { };
}
DatesDifferenceValidator.java
#Component
public class DatesDifferenceValidator implements ConstraintValidator<DatesDifference, ServiceRequest> {
#Override
public boolean isValid(ServiceRequest serviceRequest, ConstraintValidatorContext context) {
System.out.println("validation...");
if (!(serviceRequest instanceof ServiceRequest)) {
throw new IllegalArgumentException("#DatesDifference only applies to ServiceRequest");
}
LocalDate from = serviceRequest.getFromDate();
LocalDate to = serviceRequest.getToDate();
long daysBetween = ChronoUnit.DAYS.between(from, to);
System.out.println("daysBetween "+daysBetween);
return daysBetween <= 7;
}
}
ServiceRequest.java
#Getter
#Setter
#AllArgsConstructor
#NoArgsConstructor
#DatesDifference
public class ServiceRequest {
#NotBlank
private LocalDate fromDate;
#NotBlank
private LocalDate toDate;
}