SpringBoot handle #RequestParam exception - spring

Question

I have controller and method deleteFolder has #RequestParam:
#RestController
public class FolderController extends BaseController {
#DeleteMapping(path = Const.APIVersions.API_V1 + "/folders", params = "id")
public ResponseEntity<HttpStatus> deleteFolder(KeycloakAuthenticationToken authentication, #RequestParam Long id) throws EntityNotFoundException {
folderService.deleteFolder(id, authentication.getName());
return ResponseEntity.ok(HttpStatus.OK);
}
parent class:
public abstract class BaseController {
#ExceptionHandler({MissingServletRequestParameterException.class,
UnsatisfiedServletRequestParameterException.class, MethodArgumentTypeMismatchException.class,
IllegalArgumentException.class})
#ResponseStatus(HttpStatus.BAD_REQUEST)
public ResponseEntity<ErrorResponse> handleMissingServletRequestParameter(MissingServletRequestParameterException exception) {
return ResponseEntity
.status(HttpStatus.BAD_REQUEST)
.body(new ErrorResponse(HttpStatus.BAD_REQUEST.value(), exception.getMessage()));
}
I want to handle exception, when required param is missing. But that exception handler don't want to catch that exception raised from deletFolder method.
Any others handlers works.

Answer 1

You have to create custom ConstraintValidator and catch ConstraintViolationException so your base controller becomes
import org.springframework.http.*;
import org.springframework.web.bind.annotation.*;
import javax.validation.*;
public abstract class BaseController {
#ExceptionHandler({ConstraintViolationException.class})
#ResponseStatus(HttpStatus.BAD_REQUEST)
public ResponseEntity<ErrorResponse> handlerFolderNotFoundException(ConstraintViolationException exception) {
return ResponseEntity
.status(HttpStatus.BAD_REQUEST)
.body(new ErrorResponse(HttpStatus.BAD_REQUEST.value(), exception.getMessage()));
}
}
Validation Annotation
import javax.validation.*;
import java.lang.annotation.*;
#Constraint(validatedBy = FolderValidationConstraint.class)
#Target({ElementType.PARAMETER, ElementType.FIELD})
#Retention(RetentionPolicy.RUNTIME)
public #interface ValidateFolder {
String message() default "Error validating folder name";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
Validator class
import lombok.extern.slf4j.*;
import javax.validation.*;
import java.io.*;
#Slf4j
public class FolderValidationConstraint implements ConstraintValidator<ValidateFolder, String> {
#Override
public boolean isValid(String path, ConstraintValidatorContext constraintValidatorContext) {
return new File("/home/ashish/Documents/test-delete/" + path).exists();
}
}
Controller
import org.springframework.validation.annotation.*;
import org.springframework.web.bind.annotation.*;
import java.io.*;
import java.util.*;
#Validated
#RestController
#RequestMapping(path = "/folders")
public class FolderController extends BaseController {
#GetMapping
public Map<String, Boolean> delete(#ValidateFolder #RequestParam("name") String folderName) {
final File path = new File("/home/ashish/Documents/test-delete/" + folderName);
return Map.of("exists", path.exists());
}
}
Please make sure to add dependency in pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>