The ElementType.RECORD_COMPONENT, when applied to annotation for constructor parameter of a record does not work as I would anticipate.
I have this record:
public record MyRecord (
MultipartFile document
) {}
I want to ensure that document is file type application/pdf.
So I created the annotation:
#Documented
#Target({ElementType.RECORD_COMPONENT})
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = PdfValidator.class)
public #interface ValidPdf {
String message() default "MultipartFile must be application/pdf type";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
the validator:
public class PdfValidator implements ConstraintValidator<ValidPdf, MultipartFile> {
#Override
public boolean isValid(MultipartFile file, ConstraintValidatorContext context) {
if (file == null) {
return false;
}
return "application/pdf".equals(file.getContentType());
}
}
and applied it to the record:
public record MyRecord (
#ValidPdf
MultipartFile document
) {}
This however doesn't work, the validator is never called. After a few tries I managed to make it work by changing the #Target in PdfValid interface from RECORD_COMPONENT to FIELD.
#Documented
#Target({ElementType.FIELD})
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = PdfValidator.class)
public #interface ValidPdf {
String message() default "MultipartFile must be application/pdf type";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
Now it works. But why? Isn't document in MyRecord literally a record component? Why is FIELD the correct value here?
Related
So I have a type level custom annotation that checks for matching passwords in a user registration form. Even when the validator is returning false, it doesn't throw an error and show the error message. Any help is appreciated!
Entity class. Annotation in question is #ValidPassword
#Entity
#ValidPassword(fields = {"password", "matchingPassword"})
public class User {
private String password;
private String matchingPassword;
Constraintvalidator class
public class PasswordValidator implements ConstraintValidator<ValidPassword, User> {
private String[] fields;
private String message;
#Override
public boolean isValid(User user, ConstraintValidatorContext context) {
if (fields[0]== null || fields[1] == null) {
return false;
}
for ( String temp : fields) {
System.out.println(temp);
}
boolean flag = Pattern.matches("^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!#$%^&*-]).{8,}$", fields[0]);
boolean flag1 = fields[0].equals(fields[1]);
if ( !flag1 ) {
message = "Passwords do not match!";
}
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate(message)
.addPropertyNode(fields[0]).addConstraintViolation();
return flag && flag1;
}
//Show default message if no special message is set
#Override
public void initialize(ValidPassword validPassword) {
fields = validPassword.fields();
message = validPassword.message();
}
}
validpassword
#Target(ElementType.TYPE)
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = PasswordValidator.class)
#Documented
public #interface ValidPassword {
String message() default "Please enter at least 8 characters, 1 uppercase letter, 1 lowercase letter, and 1 special character";
String[] fields();
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
I am developing a Spring REST application.
I have a DTO
private String name;
#
private String nationality;
private String matchType;
private List<NC_Field> ncFields = new ArrayList();
// Getters and Setters
I have 3 tables
Field Table
Name Clearance Table
NC_Fields Table
You can have a custom validator defined with whatever logic you want.
Then you can create a custom annotation for the validator and use it in your DTO just like #NotNull
public class CustomValidator implements ConstraintValidator<MyObject, String> {
.
.
.
}
--
#Constraint(validatedBy = { CustomValidator.class })
#Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER })
#Retention(RetentionPolicy.RUNTIME)
public #interface ContactInfo {
String message() default "Invalid value";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
refer to this link for example: https://www.baeldung.com/spring-dynamic-dto-validation
I've got a simple REST resource which accepts a couple of query parameters. I'd like to validate one of these parameters, and came across ConstraintValidator for this purpose. The REST resource expects the query param territoryId to be a UUID, so I'd like to validate that it indeed is a valid UUID.
I've created an #IsValidUUID annotation, and a corresponding IsValidUUIDValidator (which is a ConstraintValidator). With what I have now, nothing gets validated and getSuggestions accepts anything I throw at it. So clearly I'm doing something wrong.
What am I doing wrong?
The REST resource now looks like this :
#Component
#Path("/search")
public class SearchResource extends AbstractResource {
#GET
#Path("/suggestions")
#Produces(MediaType.APPLICATION_XML)
public Response getSuggestions(
#QueryParam("phrase") List<String> phrases,
#IsValidUUID #QueryParam("territoryId") String territoryId) {
[...]
}
}
IsValidUUID
#Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER})
#Retention(RetentionPolicy.RUNTIME)
#Documented
#Constraint(validatedBy = {IsValidUUIDValidator.class})
public #interface IsValidUUID {
String message() default "Invalid UUID";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
IsValidUUIDValidator
public class IsValidUUIDValidator implements ConstraintValidator<IsValidUUID, String> {
#Override
public void initialize(IsValidUUID constraintAnnotation) {
}
#Override
public boolean isValid(String value, ConstraintValidatorContext context) {
if (value == null) {
return true;
}
try {
UUID.fromString(value);
return true;
} catch (Exception e) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate("The provided UUID is not valid")
.addConstraintViolation();
return false;
}
}
}
You need to set the supported targets on IsValidUUID, using the following annotation.
#SupportedValidationTarget(ValidationTarget.ANNOTATED_ELEMENT)
or
#SupportedValidationTarget(ValidationTarget.PARAMETERS)
Edit:
Sorry, I wasn't able to make it work either on a RequestParam directly. However, if you can, try creating a POJO that you can bind your request parameters to and annotate the binding field with your constraint instead. This worked for me.
public class MyModel {
#IsValidUUID
private String territoryId;
public String getTerritoryId() {
return territoryId;
}
public void setTerritoryId(String territoryId) {
this.territoryId = territoryId;
}
}
#GET
#Path("/suggestions")
#Produces(MediaType.APPLICATION_XML)
public Response getSuggestions(
#QueryParam("phrase") List<String> phrases,
#Valid #ModelAttribute MyModel myModel) {
[...]
}
I'm looking for a clean way to handle Jackson Deserialization errors for REST web requests.
More precisely: I have an Enum in a incoming DTO object, mapped from JSON. But if the user sends a wrong value, a 400 Bad Request is returned. I would like to return a 422 Unprocessable Entity with a correct message.
One option would be to accept a String, and use bean validation. However, it's not possible to pass all enum values as a list to the annotation (not a constant), so I would need to pass all enum values separately and keep them up to date. This will be very error prone over the whole application. I'm looking for a more structural way to handle this.
I solved this by using a String in the DTO and using a public #interface EnumValueas annotation.
The EnumValue:
#ReportAsSingleViolation
#Documented
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = EnumValueValidator.class)
#Target(ElementType.FIELD)
public #interface EnumValue {
Class<? extends Enum> value();
String message() default "The input contains validation errors.";
Class<?>[] groups() default { };
Class<? extends Payload>[] payload() default { };
}
The validator:
public class EnumValueValidator implements ConstraintValidator<EnumValue, String> {
private Class<? extends Enum> enumClass;
private String message;
#Override
public void initialize(final EnumValue constraintAnnotation) {
this.enumClass = constraintAnnotation.value();
this.message = constraintAnnotation.message();
}
#Override
public boolean isValid(final String value, final ConstraintValidatorContext context) {
boolean valid = false;
for (final Enum enumValue : enumClass.getEnumConstants()) {
if (enumValue.name().equals(value)) {
valid = true;
}
}
if (!valid) {
context.buildConstraintViolationWithTemplate(message) //
.addConstraintViolation();
}
return valid;
}
}
Hi am using hibernate validator in jersey rest service.
Here how can we pass value to the property file message as follows
empty.check= Please enter {0}
here in {0} i need to pass the value from annotation
#EmptyCheck(message = "{empty.check}") private String userName
here in the {0} i need to pass "user name", similarly i need to reuse message
please help me out to solve this.
You can do this by altering your annotation to provide a field description and then exposing this in the validator.
First, add a description field to your annotation:
#Target({ FIELD, METHOD, PARAMETER, ANNOTATION_TYPE })
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = EmptyCheckValidator.class)
#Documented
public #interface EmptyCheck {
String description() default "";
String message() default "{empty.check}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
Next, change your message so that it uses a named parameter; this is more readable.
empty.check= Please enter ${description}
Since you're using hibernate-validator, you can get the hibernate validator context within your validation class and add a context variable.
public class EmptyCheckValidator
implements ConstraintValidator<EmptyCheck, String> {
String description;
public final void initialize(final EmptyCheck annotation) {
this.description = annotation.description();
}
public final boolean isValid(final String value,
final ConstraintValidatorContext context) {
if(null != value && !value.isEmpty) {
return true;
}
HibernateConstraintValidatorContext ctx =
context.unwrap(HibernateConstraintValidatorContext.class);
ctx.addExpressionVariable("description", this.description);
return false;
}
}
Finally, add the description to the field:
#EmptyCheck(description = "a user name") private String userName
This should produce the following error when userName is null or empty:
Please enter a user name