I am trying to validate a method parameter using custom annotation, but annotation validator is not getting invoked.
The annotation
#Target({ElementType.METHOD, ElementType.FIELD, ElementType.CONSTRUCTOR, ElementType.PARAMETER})
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = FieldValidator.class)
public #interface ValidField {
String message() default "Incorrect field.";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
The FieldValidator
public class FieldValidator implements ConstraintValidator<ValidField, String> {
#Override
public void initialize(final ValidField arg0) {
}
#Override
public boolean isValid(final String field, final ConstraintValidatorContext context) {
System.out.println("Called annotations successfully - "+ field);
return false;
}
}
Testing through the main method
public void testAnnotation(#ValidField String q){
System.out.println("inside testAnnotation..");
}
/************************* TESTING ****************************/
public static void main(String[] args) {
Test test= new Test();
test.testAnnotation("sample");
Expected: Called annotations successfully - sample should be displayed in the console
Okay, It was a mistake testing it by the main method.
#Retention(RetentionPolicy.RUNTIME) says annotation will be available at runtime.
It was tested successfully by the service call when the server is running.
Related
There is a controller accepting code as a path variable
#RestController
#RequestMapping(value = "/api/currency")
#Validated
public class CurrencyController {
#GetMapping("/gif/{code}")
public ResponseEntity<Map> getChangeGif(#PathVariable #Code String code){
// some implementation
return null;
}
}
I want to use my own annotation to validate code as I want
#Target( { FIELD, PARAMETER })
#Retention(RUNTIME)
#Documented
#Constraint(validatedBy = CodeValidator.class)
public #interface Code {
public String message() default "error message";
public Class<?>[] groups() default {};
public Class<? extends Payload>[] payload() default {};
}
And here is the validator
public class CodeValidator implements ConstraintValidator<Code, String> {
#Override
public void initialize(Code constraintAnnotation) {
ConstraintValidator.super.initialize(constraintAnnotation);
}
#Override
public boolean isValid(String code, ConstraintValidatorContext context) {
// validator implementation
return false;
}
}
For some reason when requests come, validation just skipps, and controller continue working without it
I created my own Annotation to validate my REST parameter like this:
#PostMapping("/users")
#ResponseStatus(HttpStatus.CREATED)
public User createUser(#UserConstraint("CREATE_MODE") #RequestBody User user)
{ //code }
I got everything working where my ConstraintValidator is called to validate the User input, but I can't figure out how to get the parameter of my own annotation. I want to read the value CREATE_MODE.
#Constraint(validatedBy = UserValidator.class)
#Target(ElementType.PARAMETER )
#Retention(RetentionPolicy.RUNTIME)
public #interface UserConstraint {
String message() default "";
Class<?>[] groups() default { };
Class<? extends Payload>[] payload() default { };
public String value();
}
How to access??
public class UserValidator implements ConstraintValidator<UserConstraint, User> {
#Override
public boolean isValid(User user,
ConstraintValidatorContext context) {
???
}
#Override
public void initialize(UserConstraint annotation) {
// initialization, probably not needed
mode = annotation.value();
}
I have created a custom validator to validate the String passed to the function in converter. However, the custom validator is not being called. Am I missing something?
OperationParameter.java
#Documented
#Constraint(validatedBy = OperationParameterValidation.class)
#Target( { ElementType.PARAMETER
})
#Retention(RetentionPolicy.RUNTIME)
public #interface OperationParameter {
String message() default "Operation Parameter Invalid";
Class<?>[] groups() default { };
Class<? extends Payload>[] payload() default { };
}
OperationParameterValidation.java
public class OperationParameterValidation implements ConstraintValidator<OperationParameter, String> {
#Override
public boolean isValid(String value, ConstraintValidatorContext context) {
System.out.println("Validator called");
// validation process
// return true / false;
}
}
converter.java
#Component
public class StringToOperation implements Converter<String, Operation> {
#Override
public Operation convert(#Valid #OperationParameter String source) {
// Even I pass wrong String this function is executed successfully, and no print from validator
}
}
Service.java
public class Service {
#Autowired
ConversionService conversionService;
public void action() {
String action = "";
Operation addInsertOperation = conversionService.convert(action, Operation.class);
}
}
Set #SupportedValidationTarget(ValidationTarget.PARAMETERS) on validator class
I'm using Spring version 4.1.6.RELEASE. I have the following custom ConstraintValidator.
public class CountryCodeValidator implements ConstraintValidator<CountryCode, String> {
private List<String> allowedCountries;
#Autowired
public void setAllowedCountries(#Value("${allowed.countries}")String countries) {
allowedCountries = Arrays.asList(countries.split(","));
}
#Override
public void initialize(CountryCode constraintAnnotation) { }
#Override
public boolean isValid(String countryCode, ConstraintValidatorContext ctx) {
return null != countryCode && allowedCountries.contains(countryCode.toUpperCase());
}
}
and I have the following annotation
#Documented
#Constraint(validatedBy = CountryCodeValidator.class)
#Target({ElementType.FIELD})
#Retention(RetentionPolicy.RUNTIME)
public #interface CountryCode {
String message() default "{CountryCode}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
I'm using this in a request object like the following
#CountryCode(message = MessageKeys.COUNTRY_CODE_INVALID)
private String countryCode;
When I run the application, everything is working as expected. However in the unit test for the controller it is failing.
My unit test code is like the following
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = "classpath:/test-context.xml")
public class ControllerTest {
#InjectMocks
private Controller controller;
#Before
public void init() {
MockitoAnnotations.initMocks(this);
}
#Test
public void testEndpoint() {
Request request = new Request();
RestAssuredMockMvc.given().standaloneSetup(controller).contentType(MediaType.APPLICATION_JSON_VALUE).body(request)
.post("/endpoint").then().statusCode(HttpStatus.OK.value());
}
}
When I run the code I could not get #Value("${allowed.countries}"), therefore I'm receiving a null pointer exception in the isValid method.
What am I missing?
Thanks in advance
After learning about Hibernate Custom Validators, it has given me an interest in one topic, could I possibly create one base annotation wherein I could set which Validator to use?
#Target({ ElementType.FIELD })
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = validator().class)
public #interface CustomAnnotation {
public String message();
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
Class<? extends ConstraintValidator<? extends CustomAnnotation, Serializable>> validator();
}
So that I could use #CustomAnnotation in this manner
#CustomAnnotation(validator = CustomConstraintValidator.class, message = "validationMessage")
private Object fieldName;
I would not recommend it but you can do it roughly this way:
#Target({ ElementType.FIELD })
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = GenericValidatorBootstrapperValidator.class)
public #interface CustomAnnotation {
public String message();
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
Class<? extends ConstraintValidator<? extends CustomAnnotation, Serializable>> validator();
}
public class GenericValidatorBootstrapperValidator implements ConstraintValidator<CustomAnnotation, Object> {
private final ConstraintValidator validator;
#Override
public void initialize(CustomAnnotation constraintAnnotation) {
Class<? extends ConstraintValidator> validatorClass = constraintAnnotation.validator();
validator = validatorClass.newInstance();
validator.initialize( ... ); //TODO with what?
}
#Override
public boolean isValid(Object value, ConstraintValidatorContext context) {
return validator.isValid(value, context);
}
}
But again, prefer specific annotations, they are more expressive.
Edit
After your comment, I think what you want is to be able to set different validators based on the return type of the property
#CustomAnnotation
List<String> foo;
#CustomAnnotation
Table bar;
If that's the case, add several validators implementations in the #Constraint annotation.
#Target({ ElementType.FIELD })
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = {ListValidatorImpl.class, TableValidatorImpl.class, ...})
public #interface CustomAnnotation {
public String message();
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
public class ListValidatorImpl implements ConstraintValidator<CustomAnnotation, List> {
#Override
public boolean isValid(List value, ConstraintValidatorContext context) {
}
}
public class TableValidatorImpl implements ConstraintValidator<CustomAnnotation, Table> {
#Override
public boolean isValid(Table value, ConstraintValidatorContext context) {
}
}
You can even link a contraint annotation with an implementation via the META/validation.xml file
<constraint-mappings
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://jboss.org/xml/ns/javax/validation/mapping validation-mapping-1.1.xsd"
xmlns="http://jboss.org/xml/ns/javax/validation/mapping" version="1.1">
<constraint-definition annotation="org.mycompany.CustomAnnotation">
<validated-by include-existing-validators="true">
<value>org.mycompany.EnumCustomValidatorImpl</value>
</validated-by>
</constraint-definition>
</constraint-mappings>
If you need something more flexible, I think my initial proposal would work. In the GenericValidatorBootstrapperValidator isValid method, you could call the right validator instance based on the object type of the value parameter (via instanceof for example).
Hibernate Validator also offers now a annotation #ScriptAssert which makes the implementation of custom validations easier and helps to avoid plenty lines of code.
Example of use:
#ScriptAssert(lang = "javascript",
script = "_this.capital.equals(_this.capital.toUpperCase)",
message = "capital has not Capital letters")
public class BigLetters {
private String capital;
public String getCapital() {
return capital;
}
public void setCapital(String capital) {
this.capital = capital;
}
}
I don't think you can implement a dynamic validator resolver on top of Hibernate Validator support. It's much better to have a dedicated set of annotation-validator pairs so when you annotate a field with a specific Validation annotation, it's clear what Validator will be used.