I am working on cross field validation using javax validation API in Spring Boot Application. I have a User bean and i have to validate that both firstname and lastname are not null/empty. At least one of this field should have a value.
I have created custom annotation (NameMatch.java) and custom Validator (NameValidator.java) for this requirement.
#NameMatch(first = "firstname", second = "lastname", message = "The first and lastname can't be null")
public class User {
private String firstname;
private String lastname;
#NotNull
#Email
private String email;
#NotNull
private String phone;
}
NameMatch.java
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Constraint(validatedBy = NameValidator.class)
#Documented
public #interface NameMatch
{
String message() default "{constraints.fieldmatch}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
/**
* #return The first field
*/
String first();
/**
* #return The second field
*/
String second();
}
NameValidator.java
public class NameValidator implements ConstraintValidator<NameMatch, Object>
{
private String firstFieldName;
private String secondFieldName;
#Override
public void initialize(final NameMatch constraintAnnotation)
{
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
}
#Override
public boolean isValid(final Object value, final ConstraintValidatorContext context)
{
boolean isValidName = false;
try
{
final Object firstName = BeanUtils.getProperty(value, firstFieldName);
final Object lastName = BeanUtils.getProperty(value, secondFieldName);
// Validation logic
}
catch (final Exception ignore)
{
}
return isValidName;
}
}
UserValidator.java
public class UserValidator
{
public void isValidUser()
{
//Create ValidatorFactory which returns validator
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
//It validates bean instances
Validator validator = factory.getValidator();
User user = new User();
user.setEmail("test#gmail.com");
user.setPhone("12345678")
//Validate bean
Set<ConstraintViolation<User>> constraintViolations = validator.validate(user);
//Show errors
if (constraintViolations.size() > 0) {
for (ConstraintViolation<User> violation : constraintViolations) {
System.out.println(violation.getMessage());
}
} else {
System.out.println("Valid Object");
}
}
}
I have to write JUnit test cases for the Custom Validator class. I explored hibernate validator docs but couldn't find a way to invoke custom validator method through JUnit. Can someone please help to write JUnit test cases for above scenario.
Your NameValidator has public methods, so you can instantiate an object and write unit tests like for any other public method.
A possible JUnit 5 test with Mockito can look like the following:
#ExtendWith(MockitoExtension.class)
class NameValidatorTest {
#Mock
private NameMatch nameMatch;
#Mock
private ConstraintValidatorContext constraintValidatorContext;
#Test
public void testIsValid() {
when(nameMatch.first()).thenReturn("firstname");
when(nameMatch.second()).thenReturn("lastname");
NameValidator nameValidator = new NameValidator();
nameValidator.initialize(nameMatch);
User user = new User();
user.setFirstname("Duke");
user.setLastname("Duke");
boolean result = nameValidator.isValid(user, constraintValidatorContext);
assertTrue(result);
}
}
Depending of what you need the ConstraintValidatorContext you might also want to mock methods or later verify that specific methods were invoked.
If you are not using JUnit 5, you can adjust the code to not the JUnit 5 MockitoExtension and create the mocks using Mockito.mock().
One way is definitely Mockito (as #rieckpil mentioned).
If you dont want that, and actually want to invoke the validator, you can have something like this:
#SpringBootTest
public class NameValidatorUnitTest {
#Test
public void whenExistingRootRole_thenFail()
{
AnnotationDescriptor<NameMatch> descriptor = new AnnotationDescriptor<NameMatch>( NameMatch.class );
AnnotationFactory.create( descriptor );
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
User user = new User();
user.setEmail("test#gmail.com");
user.setPhone("12345678");
Set<ConstraintViolation<User>> constraintViolations = validator.validate(user);
if (constraintViolations.size() > 0) {
for (ConstraintViolation<User> violation : constraintViolations) {
System.out.println(violation.getMessage());
}
} else {
System.out.println("Valid Object");
}
Assert.assertEquals(true, constraintViolations.size()>0);
}
}
This question is very similar to this one, but I dont know where to start.
Suppose I have an action like this:
#GetMapping("/foo/{id}")
public Collection<Foo> listById(#PathVariable("id") string id) {
return null;
}
How could one intercept the listById method and change the value of id (Eg.: concat a string, pad with zeros etc)?
My scenario is that mostly of the IDs are left-padded with zeros (lengths differ) and I dont want to leave this to my ajax calls.
Expected solution:
#GetMapping("/foo/{id}")
public Collection<Foo> listById(#PathVariablePad("id", 4) string id) {
// id would be "0004" on "/foo/4" calls
return null;
}
Ok, here is how I've done it.
Since we can't inherit annotations and thus #PathVariable's target are only parameters, we have to create a new annotation, as follows:
#Target(ElementType.PARAMETER)
#Retention(RetentionPolicy.RUNTIME)
public #interface PathVariablePad {
int zeros() default 0;
#AliasFor("name")
String value() default "";
#AliasFor("value")
String name() default "";
boolean required() default true;
}
Now we need to create a HandlerMethodArgumentResolver. In this case, since all I want is to left-pad a #PathVariable with zeros, we're going to inherit PathVariableMethodArgumentResolver, like this:
public class PathVariablePadderMethodArgumentResolver extends PathVariableMethodArgumentResolver {
private String leftPadWithZeros(Object target, int zeros) {
return String.format("%1$" + zeros + "s", target.toString()).replace(' ', '0'); // Eeeewwwwwwwwwwww!
}
#Override
public boolean supportsParameter(MethodParameter parameter) {
return parameter.hasParameterAnnotation(PathVariablePad.class);
}
#Override
protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
PathVariablePad pvp = parameter.getParameterAnnotation(PathVariablePad.class);
return new NamedValueInfo(pvp.name(), pvp.required(), leftPadWithZeros("", pvp.zeros()));
}
#Override
protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request) throws Exception {
PathVariablePad pvp = parameter.getParameterAnnotation(PathVariablePad.class);
return leftPadWithZeros(super.resolveName(name, parameter, request), pvp.zeros());
}
}
Finally, let's register our method argument resolver (xml):
<mvc:annotation-driven>
<mvc:argument-resolvers>
<bean class="my.package.PathVariablePadderMethodArgumentResolver" />
</mvc:argument-resolvers>
</mvc:annotation-driven>
The usage is pretty simple and heres how to do this:
#GetMapping("/ten/{id}")
public void ten(#PathVariablePad(zeros = 10) String id) {
// id would be "0000000001" on "/ten/1" calls
}
#GetMapping("/five/{id}")
public void five(#PathVariablePad(zeros = 5) String id) {
// id would be "00001" on "/five/1" calls
}
Spring #InitBinder annotation and WebDataBinder class will help you to intercept parameter and process it's value before controller method call.
Documentation:
InitBinder
WebDataBinder
Full code pattern:
#RestController
public class FooController {
#InitBinder
private void initBinder(WebDataBinder binder) {
binder.registerCustomEditor(String.class, new PropertyEditorSupport() {
#Override
public void setAsText(String text) throws IllegalArgumentException {
super.setValue("000" + text);
}
} );
}
#GetMapping(value = "/foo/{id}")
public Foo sayHello(
#PathVariable(value = "id") String id
) {
return new Foo(id);
}
#XmlRootElement
#XmlAccessorType(XmlAccessType.FIELD)
public static class Foo {
#XmlElement(name = "id")
private String id;
public Foo(String id) {
this.id = id;
}
public Foo() {
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
}
}
And the usage:
curl http://localhost:8080/foo/10 | xmllint --format -
Response:
<foo>
<id>00010</id>
</foo>
This is quite similar, but for Decoding the #PathVariable value, as brought here by #yanefedor, but applied to all Controllers in the application:
#org.springframework.web.bind.annotation.ControllerAdvice
public class ControllerAdvice {
/**
* Just to decode the data parsed into the Controller's methods parameters annotated with #PathVariable.
*
* #param binder
*/
#InitBinder
private void initBinder(WebDataBinder binder) {
binder.registerCustomEditor(String.class, new PropertyEditorSupport() {
#Override
public void setAsText(String text) throws IllegalArgumentException {
if (text == null) {
super.setValue(null);
} else {
super.setValue(UriUtils.decode(text, Charset.defaultCharset()));
}
}
});
}
}
Is there an implementation of (or third-party implementation for) cross field validation in Hibernate Validator 4.x? If not, what is the cleanest way to implement a cross field validator?
As an example, how can you use the API to validate two bean properties are equal (such as validating a password field matches the password verify field).
In annotations, I'd expect something like:
public class MyBean {
#Size(min=6, max=50)
private String pass;
#Equals(property="pass")
private String passVerify;
}
Each field constraint should be handled by a distinct validator annotation, or in other words it's not suggested practice to have one field's validation annotation checking against other fields; cross-field validation should be done at the class level. Additionally, the JSR-303 Section 2.2 preferred way to express multiple validations of the same type is via a list of annotations. This allows the error message to be specified per match.
For example, validating a common form:
#FieldMatch.List({
#FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match"),
#FieldMatch(first = "email", second = "confirmEmail", message = "The email fields must match")
})
public class UserRegistrationForm {
#NotNull
#Size(min=8, max=25)
private String password;
#NotNull
#Size(min=8, max=25)
private String confirmPassword;
#NotNull
#Email
private String email;
#NotNull
#Email
private String confirmEmail;
}
The Annotation:
package constraints;
import constraints.impl.FieldMatchValidator;
import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.Documented;
import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.TYPE;
import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Target;
/**
* Validation annotation to validate that 2 fields have the same value.
* An array of fields and their matching confirmation fields can be supplied.
*
* Example, compare 1 pair of fields:
* #FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match")
*
* Example, compare more than 1 pair of fields:
* #FieldMatch.List({
* #FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match"),
* #FieldMatch(first = "email", second = "confirmEmail", message = "The email fields must match")})
*/
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Constraint(validatedBy = FieldMatchValidator.class)
#Documented
public #interface FieldMatch
{
String message() default "{constraints.fieldmatch}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
/**
* #return The first field
*/
String first();
/**
* #return The second field
*/
String second();
/**
* Defines several <code>#FieldMatch</code> annotations on the same element
*
* #see FieldMatch
*/
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Documented
#interface List
{
FieldMatch[] value();
}
}
The Validator:
package constraints.impl;
import constraints.FieldMatch;
import org.apache.commons.beanutils.BeanUtils;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object>
{
private String firstFieldName;
private String secondFieldName;
#Override
public void initialize(final FieldMatch constraintAnnotation)
{
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
}
#Override
public boolean isValid(final Object value, final ConstraintValidatorContext context)
{
try
{
final Object firstObj = BeanUtils.getProperty(value, firstFieldName);
final Object secondObj = BeanUtils.getProperty(value, secondFieldName);
return firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
}
catch (final Exception ignore)
{
// ignore
}
return true;
}
}
I suggest you another possible solution. Perhaps less elegant, but easier!
public class MyBean {
#Size(min=6, max=50)
private String pass;
private String passVerify;
#NotNull
private LocalDate passExpiry;
#NotNull
private LocalDate dateOfJoining;
#AssertTrue(message = "Fields `pass` and `passVerify` should be equal")
// Any method name is ok als long it begins with `is`
private boolean isValidPass() {
//return pass == null && passVerify == null || pass.equals(passVerify);
// Since Java 7:
return Objects.equals(pass, passVerify);
}
#AssertTrue(message = "Field `passExpiry` should be later than `dateOfJoining`")
// Other rules can also be validated in other methods
private boolean isPassExpiryAfterDateOfJoining() {
return dateOfJoining.isBefore(passExpiry);
}
}
The isValid() and isPassExpiryAfterDateOfJoining() methods are invoked automatically by the validator. The property paths reported in the ConstraintViolations will be extracted from the method names: valid and passExpiryAfterDateOfJoining.
I'm surprised this isn't available out of the box. Anyway, here is a possible solution.
I've created a class level validator, not the field level as described in the original question.
Here is the annotation code:
package com.moa.podium.util.constraints;
import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.validation.Constraint;
import javax.validation.Payload;
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Constraint(validatedBy = MatchesValidator.class)
#Documented
public #interface Matches {
String message() default "{com.moa.podium.util.constraints.matches}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String field();
String verifyField();
}
And the validator itself:
package com.moa.podium.util.constraints;
import org.mvel2.MVEL;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
public class MatchesValidator implements ConstraintValidator<Matches, Object> {
private String field;
private String verifyField;
public void initialize(Matches constraintAnnotation) {
this.field = constraintAnnotation.field();
this.verifyField = constraintAnnotation.verifyField();
}
public boolean isValid(Object value, ConstraintValidatorContext context) {
Object fieldObj = MVEL.getProperty(field, value);
Object verifyFieldObj = MVEL.getProperty(verifyField, value);
boolean neitherSet = (fieldObj == null) && (verifyFieldObj == null);
if (neitherSet) {
return true;
}
boolean matches = (fieldObj != null) && fieldObj.equals(verifyFieldObj);
if (!matches) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate("message")
.addNode(verifyField)
.addConstraintViolation();
}
return matches;
}
}
Note that I've used MVEL to inspect the properties of the object being validated. This could be replaced with the standard reflection APIs or if it is a specific class you are validating, the accessor methods themselves.
The #Matches annotation can then be used used on a bean as follows:
#Matches(field="pass", verifyField="passRepeat")
public class AccountCreateForm {
#Size(min=6, max=50)
private String pass;
private String passRepeat;
...
}
As a disclaimer, I wrote this in the last 5 minutes, so I probably haven't ironed out all the bugs yet. I'll update the answer if anything goes wrong.
With Hibernate Validator 4.1.0.Final I recommend using #ScriptAssert. Exceprt from its JavaDoc:
Script expressions can be written in any scripting or expression
language, for which a JSR 223 ("Scripting for the JavaTM Platform")
compatible engine can be found on the classpath.
Note: the evaluation is being performed by a scripting "engine" running in the Java VM, therefore on Java "server side", not on "client side" as stated in some comments.
Example:
#ScriptAssert(lang = "javascript", script = "_this.passVerify.equals(_this.pass)")
public class MyBean {
#Size(min=6, max=50)
private String pass;
private String passVerify;
}
or with shorter alias and null-safe:
#ScriptAssert(lang = "javascript", alias = "_",
script = "_.passVerify != null && _.passVerify.equals(_.pass)")
public class MyBean {
#Size(min=6, max=50)
private String pass;
private String passVerify;
}
or with Java 7+ null-safe Objects.equals():
#ScriptAssert(lang = "javascript", script = "Objects.equals(_this.passVerify, _this.pass)")
public class MyBean {
#Size(min=6, max=50)
private String pass;
private String passVerify;
}
Nevertheless, there is nothing wrong with a custom class level validator #Matches solution.
Cross fields validations can be done by creating custom constraints.
Example:- Compare password and confirmPassword fields of User instance.
CompareStrings
#Target({TYPE})
#Retention(RUNTIME)
#Constraint(validatedBy=CompareStringsValidator.class)
#Documented
public #interface CompareStrings {
String[] propertyNames();
StringComparisonMode matchMode() default EQUAL;
boolean allowNull() default false;
String message() default "";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
StringComparisonMode
public enum StringComparisonMode {
EQUAL, EQUAL_IGNORE_CASE, NOT_EQUAL, NOT_EQUAL_IGNORE_CASE
}
CompareStringsValidator
public class CompareStringsValidator implements ConstraintValidator<CompareStrings, Object> {
private String[] propertyNames;
private StringComparisonMode comparisonMode;
private boolean allowNull;
#Override
public void initialize(CompareStrings constraintAnnotation) {
this.propertyNames = constraintAnnotation.propertyNames();
this.comparisonMode = constraintAnnotation.matchMode();
this.allowNull = constraintAnnotation.allowNull();
}
#Override
public boolean isValid(Object target, ConstraintValidatorContext context) {
boolean isValid = true;
List<String> propertyValues = new ArrayList<String> (propertyNames.length);
for(int i=0; i<propertyNames.length; i++) {
String propertyValue = ConstraintValidatorHelper.getPropertyValue(String.class, propertyNames[i], target);
if(propertyValue == null) {
if(!allowNull) {
isValid = false;
break;
}
} else {
propertyValues.add(propertyValue);
}
}
if(isValid) {
isValid = ConstraintValidatorHelper.isValid(propertyValues, comparisonMode);
}
if (!isValid) {
/*
* if custom message was provided, don't touch it, otherwise build the
* default message
*/
String message = context.getDefaultConstraintMessageTemplate();
message = (message.isEmpty()) ? ConstraintValidatorHelper.resolveMessage(propertyNames, comparisonMode) : message;
context.disableDefaultConstraintViolation();
ConstraintViolationBuilder violationBuilder = context.buildConstraintViolationWithTemplate(message);
for (String propertyName : propertyNames) {
NodeBuilderDefinedContext nbdc = violationBuilder.addNode(propertyName);
nbdc.addConstraintViolation();
}
}
return isValid;
}
}
ConstraintValidatorHelper
public abstract class ConstraintValidatorHelper {
public static <T> T getPropertyValue(Class<T> requiredType, String propertyName, Object instance) {
if(requiredType == null) {
throw new IllegalArgumentException("Invalid argument. requiredType must NOT be null!");
}
if(propertyName == null) {
throw new IllegalArgumentException("Invalid argument. PropertyName must NOT be null!");
}
if(instance == null) {
throw new IllegalArgumentException("Invalid argument. Object instance must NOT be null!");
}
T returnValue = null;
try {
PropertyDescriptor descriptor = new PropertyDescriptor(propertyName, instance.getClass());
Method readMethod = descriptor.getReadMethod();
if(readMethod == null) {
throw new IllegalStateException("Property '" + propertyName + "' of " + instance.getClass().getName() + " is NOT readable!");
}
if(requiredType.isAssignableFrom(readMethod.getReturnType())) {
try {
Object propertyValue = readMethod.invoke(instance);
returnValue = requiredType.cast(propertyValue);
} catch (Exception e) {
e.printStackTrace(); // unable to invoke readMethod
}
}
} catch (IntrospectionException e) {
throw new IllegalArgumentException("Property '" + propertyName + "' is NOT defined in " + instance.getClass().getName() + "!", e);
}
return returnValue;
}
public static boolean isValid(Collection<String> propertyValues, StringComparisonMode comparisonMode) {
boolean ignoreCase = false;
switch (comparisonMode) {
case EQUAL_IGNORE_CASE:
case NOT_EQUAL_IGNORE_CASE:
ignoreCase = true;
}
List<String> values = new ArrayList<String> (propertyValues.size());
for(String propertyValue : propertyValues) {
if(ignoreCase) {
values.add(propertyValue.toLowerCase());
} else {
values.add(propertyValue);
}
}
switch (comparisonMode) {
case EQUAL:
case EQUAL_IGNORE_CASE:
Set<String> uniqueValues = new HashSet<String> (values);
return uniqueValues.size() == 1 ? true : false;
case NOT_EQUAL:
case NOT_EQUAL_IGNORE_CASE:
Set<String> allValues = new HashSet<String> (values);
return allValues.size() == values.size() ? true : false;
}
return true;
}
public static String resolveMessage(String[] propertyNames, StringComparisonMode comparisonMode) {
StringBuffer buffer = concatPropertyNames(propertyNames);
buffer.append(" must");
switch(comparisonMode) {
case EQUAL:
case EQUAL_IGNORE_CASE:
buffer.append(" be equal");
break;
case NOT_EQUAL:
case NOT_EQUAL_IGNORE_CASE:
buffer.append(" not be equal");
break;
}
buffer.append('.');
return buffer.toString();
}
private static StringBuffer concatPropertyNames(String[] propertyNames) {
//TODO improve concating algorithm
StringBuffer buffer = new StringBuffer();
buffer.append('[');
for(String propertyName : propertyNames) {
char firstChar = Character.toUpperCase(propertyName.charAt(0));
buffer.append(firstChar);
buffer.append(propertyName.substring(1));
buffer.append(", ");
}
buffer.delete(buffer.length()-2, buffer.length());
buffer.append("]");
return buffer;
}
}
User
#CompareStrings(propertyNames={"password", "confirmPassword"})
public class User {
private String password;
private String confirmPassword;
public String getPassword() { return password; }
public void setPassword(String password) { this.password = password; }
public String getConfirmPassword() { return confirmPassword; }
public void setConfirmPassword(String confirmPassword) { this.confirmPassword = confirmPassword; }
}
Test
public void test() {
User user = new User();
user.setPassword("password");
user.setConfirmPassword("paSSword");
Set<ConstraintViolation<User>> violations = beanValidator.validate(user);
for(ConstraintViolation<User> violation : violations) {
logger.debug("Message:- " + violation.getMessage());
}
Assert.assertEquals(violations.size(), 1);
}
Output Message:- [Password, ConfirmPassword] must be equal.
By using the CompareStrings validation constraint, we can also compare more than two properties and we can mix any of four string comparison methods.
ColorChoice
#CompareStrings(propertyNames={"color1", "color2", "color3"}, matchMode=StringComparisonMode.NOT_EQUAL, message="Please choose three different colors.")
public class ColorChoice {
private String color1;
private String color2;
private String color3;
......
}
Test
ColorChoice colorChoice = new ColorChoice();
colorChoice.setColor1("black");
colorChoice.setColor2("white");
colorChoice.setColor3("white");
Set<ConstraintViolation<ColorChoice>> colorChoiceviolations = beanValidator.validate(colorChoice);
for(ConstraintViolation<ColorChoice> violation : colorChoiceviolations) {
logger.debug("Message:- " + violation.getMessage());
}
Output Message:- Please choose three different colors.
Similarly, we can have CompareNumbers, CompareDates, etc cross-fields validation constraints.
P.S. I have not tested this code under production environment (though I tested it under dev environment), so consider this code as Milestone Release. If you find a bug, please write a nice comment. :)
If you’re using the Spring Framework then you can use the Spring Expression Language (SpEL) for that. I’ve wrote a small library that provides JSR-303 validator based on SpEL – it makes cross-field validations a breeze! Take a look at https://github.com/jirutka/validator-spring.
This will validate length and equality of the password fields.
#SpELAssert(value = "pass.equals(passVerify)",
message = "{validator.passwords_not_same}")
public class MyBean {
#Size(min = 6, max = 50)
private String pass;
private String passVerify;
}
You can also easily modify this to validate the password fields only when not both empty.
#SpELAssert(value = "pass.equals(passVerify)",
applyIf = "pass || passVerify",
message = "{validator.passwords_not_same}")
public class MyBean {
#Size(min = 6, max = 50)
private String pass;
private String passVerify;
}
I have tried Alberthoven's example (hibernate-validator 4.0.2.GA) and i get an ValidationException: „Annotated methods must follow the JavaBeans naming convention. match() does not.“ too. After I renamed the method from „match“ to "isValid" it works.
public class Password {
private String password;
private String retypedPassword;
public Password(String password, String retypedPassword) {
super();
this.password = password;
this.retypedPassword = retypedPassword;
}
#AssertTrue(message="password should match retyped password")
private boolean isValid(){
if (password == null) {
return retypedPassword == null;
} else {
return password.equals(retypedPassword);
}
}
public String getPassword() {
return password;
}
public String getRetypedPassword() {
return retypedPassword;
}
}
I like the idea from Jakub Jirutka to use Spring Expression Language. If you don't want to add another library/dependency (assuming that you already use Spring), here is a simplified implementation of his idea.
The constraint:
#Constraint(validatedBy=ExpressionAssertValidator.class)
#Target({ElementType.TYPE})
#Retention(RetentionPolicy.RUNTIME)
public #interface ExpressionAssert {
String message() default "expression must evaluate to true";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String value();
}
The validator:
public class ExpressionAssertValidator implements ConstraintValidator<ExpressionAssert, Object> {
private Expression exp;
public void initialize(ExpressionAssert annotation) {
ExpressionParser parser = new SpelExpressionParser();
exp = parser.parseExpression(annotation.value());
}
public boolean isValid(Object value, ConstraintValidatorContext context) {
return exp.getValue(value, Boolean.class);
}
}
Apply like this:
#ExpressionAssert(value="pass == passVerify", message="passwords must be same")
public class MyBean {
#Size(min=6, max=50)
private String pass;
private String passVerify;
}
I made a small adaptation in Nicko's solution so that it is not necessary to use the Apache Commons BeanUtils library and replace it with the solution already available in spring, for those using it as I can be simpler:
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.PropertyAccessorFactory;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object> {
private String firstFieldName;
private String secondFieldName;
#Override
public void initialize(final FieldMatch constraintAnnotation) {
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
}
#Override
public boolean isValid(final Object object, final ConstraintValidatorContext context) {
BeanWrapper beanWrapper = PropertyAccessorFactory.forBeanPropertyAccess(object);
final Object firstObj = beanWrapper.getPropertyValue(firstFieldName);
final Object secondObj = beanWrapper.getPropertyValue(secondFieldName);
boolean isValid = firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
if (!isValid) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate(context.getDefaultConstraintMessageTemplate())
.addPropertyNode(firstFieldName)
.addConstraintViolation();
}
return isValid;
}
}
I don't have the reputation for commenting on the first answer but wanted to add that I have added unit tests for the winning answer and have the following observations:
If you get the first or field names wrong then you get a validation error as though the values don't match. Don't get tripped up by spelling mistakes e.g.
#FieldMatch(first="invalidFieldName1", second="validFieldName2")
The validator will accept equivalent data types i.e. these will all pass with FieldMatch:
private String stringField = "1";
private Integer integerField = new Integer(1)
private int intField = 1;
If the fields are of an object type which does not implement equals, the validation will fail.
Very nice solution bradhouse. Is there any way to apply the #Matches annotation to more than one field?
EDIT:
Here's the solution I came up with to answer this question, I modified the Constraint to accept an array instead of a single value:
#Matches(fields={"password", "email"}, verifyFields={"confirmPassword", "confirmEmail"})
public class UserRegistrationForm {
#NotNull
#Size(min=8, max=25)
private String password;
#NotNull
#Size(min=8, max=25)
private String confirmPassword;
#NotNull
#Email
private String email;
#NotNull
#Email
private String confirmEmail;
}
The code for the annotation:
package springapp.util.constraints;
import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.validation.Constraint;
import javax.validation.Payload;
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Constraint(validatedBy = MatchesValidator.class)
#Documented
public #interface Matches {
String message() default "{springapp.util.constraints.matches}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String[] fields();
String[] verifyFields();
}
And the implementation:
package springapp.util.constraints;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import org.apache.commons.beanutils.BeanUtils;
public class MatchesValidator implements ConstraintValidator<Matches, Object> {
private String[] fields;
private String[] verifyFields;
public void initialize(Matches constraintAnnotation) {
fields = constraintAnnotation.fields();
verifyFields = constraintAnnotation.verifyFields();
}
public boolean isValid(Object value, ConstraintValidatorContext context) {
boolean matches = true;
for (int i=0; i<fields.length; i++) {
Object fieldObj, verifyFieldObj;
try {
fieldObj = BeanUtils.getProperty(value, fields[i]);
verifyFieldObj = BeanUtils.getProperty(value, verifyFields[i]);
} catch (Exception e) {
//ignore
continue;
}
boolean neitherSet = (fieldObj == null) && (verifyFieldObj == null);
if (neitherSet) {
continue;
}
boolean tempMatches = (fieldObj != null) && fieldObj.equals(verifyFieldObj);
if (!tempMatches) {
addConstraintViolation(context, fields[i]+ " fields do not match", verifyFields[i]);
}
matches = matches?tempMatches:matches;
}
return matches;
}
private void addConstraintViolation(ConstraintValidatorContext context, String message, String field) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate(message).addNode(field).addConstraintViolation();
}
}
You need to call it explicitly. In the example above, bradhouse has given you all the steps to write a custom constraint.
Add this code in your caller class.
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
validator = factory.getValidator();
Set<ConstraintViolation<yourObjectClass>> constraintViolations = validator.validate(yourObject);
in the above case it would be
Set<ConstraintViolation<AccountCreateForm>> constraintViolations = validator.validate(objAccountCreateForm);
Why not try Oval: http://oval.sourceforge.net/
I looks like it supports OGNL so maybe you could do it by a more natural
#Assert(expr = "_value ==_this.pass").
You guys are awesome. Really amazing ideas. I like Alberthoven's and McGin's most, so I decided to combine both ideas. And develop some generic solution to cater all cases. Here is my proposed solution.
#Documented
#Constraint(validatedBy = NotFalseValidator.class)
#Target({ElementType.METHOD, ElementType.FIELD,ElementType.TYPE})
#Retention(RetentionPolicy.RUNTIME)
public #interface NotFalse {
String message() default "NotFalse";
String[] messages();
String[] properties();
String[] verifiers();
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
public class NotFalseValidator implements ConstraintValidator<NotFalse, Object> {
private String[] properties;
private String[] messages;
private String[] verifiers;
#Override
public void initialize(NotFalse flag) {
properties = flag.properties();
messages = flag.messages();
verifiers = flag.verifiers();
}
#Override
public boolean isValid(Object bean, ConstraintValidatorContext cxt) {
if(bean == null) {
return true;
}
boolean valid = true;
BeanWrapper beanWrapper = PropertyAccessorFactory.forBeanPropertyAccess(bean);
for(int i = 0; i< properties.length; i++) {
Boolean verified = (Boolean) beanWrapper.getPropertyValue(verifiers[i]);
valid &= isValidProperty(verified,messages[i],properties[i],cxt);
}
return valid;
}
boolean isValidProperty(Boolean flag,String message, String property, ConstraintValidatorContext cxt) {
if(flag == null || flag) {
return true;
} else {
cxt.disableDefaultConstraintViolation();
cxt.buildConstraintViolationWithTemplate(message)
.addPropertyNode(property)
.addConstraintViolation();
return false;
}
}
}
#NotFalse(
messages = {"End Date Before Start Date" , "Start Date Before End Date" } ,
properties={"endDateTime" , "startDateTime"},
verifiers = {"validDateRange" , "validDateRange"})
public class SyncSessionDTO implements ControllableNode {
#NotEmpty #NotPastDate
private Date startDateTime;
#NotEmpty
private Date endDateTime;
public Date getStartDateTime() {
return startDateTime;
}
public void setStartDateTime(Date startDateTime) {
this.startDateTime = startDateTime;
}
public Date getEndDateTime() {
return endDateTime;
}
public void setEndDateTime(Date endDateTime) {
this.endDateTime = endDateTime;
}
public Boolean getValidDateRange(){
if(startDateTime != null && endDateTime != null) {
return startDateTime.getTime() <= endDateTime.getTime();
}
return null;
}
}
Solution realated with question:
How to access a field which is described in annotation property
#Target(ElementType.FIELD)
#Retention(RetentionPolicy.RUNTIME)
#Documented
public #interface Match {
String field();
String message() default "";
}
#Target(ElementType.TYPE)
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy = MatchValidator.class)
#Documented
public #interface EnableMatchConstraint {
String message() default "Fields must match!";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
public class MatchValidator implements ConstraintValidator<EnableMatchConstraint, Object> {
#Override
public void initialize(final EnableMatchConstraint constraint) {}
#Override
public boolean isValid(final Object o, final ConstraintValidatorContext context) {
boolean result = true;
try {
String mainField, secondField, message;
Object firstObj, secondObj;
final Class<?> clazz = o.getClass();
final Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
if (field.isAnnotationPresent(Match.class)) {
mainField = field.getName();
secondField = field.getAnnotation(Match.class).field();
message = field.getAnnotation(Match.class).message();
if (message == null || "".equals(message))
message = "Fields " + mainField + " and " + secondField + " must match!";
firstObj = BeanUtils.getProperty(o, mainField);
secondObj = BeanUtils.getProperty(o, secondField);
result = firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
if (!result) {
context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate(message).addPropertyNode(mainField).addConstraintViolation();
break;
}
}
}
} catch (final Exception e) {
// ignore
//e.printStackTrace();
}
return result;
}
}
And how to use it...? Like this:
#Entity
#EnableMatchConstraint
public class User {
#NotBlank
private String password;
#Match(field = "password")
private String passwordConfirmation;
}
I'm looking to do a little custom validation with JSR-303 javax.validation.
I have a field. And If a certain value is entered into this field I want to require that a few other fields are not null.
I'm trying to figure this out. Not sure exactly what I would call this to help find an explanation.
Any help would be appreciated. I am pretty new to this.
At the moment I'm thinking a Custom Constraint. But I'm not sure how to test the value of the dependent field from within the annotation. Basically I'm not sure how to access the panel object from the annotation.
public class StatusValidator implements ConstraintValidator<NotNull, String> {
#Override
public void initialize(NotNull constraintAnnotation) {}
#Override
public boolean isValid(String value, ConstraintValidatorContext context) {
if ("Canceled".equals(panel.status.getValue())) {
if (value != null) {
return true;
}
} else {
return false;
}
}
}
It's the panel.status.getValue(); giving me trouble.. not sure how to accomplish this.
Define method that must validate to true and put the #AssertTrue annotation on the top of it:
#AssertTrue
private boolean isOk() {
return someField != something || otherField != null;
}
The method must start with 'is'.
In this case I suggest to write a custom validator, which will validate at class level (to allow us get access to object's fields) that one field is required only if another field has particular value. Note that you should write generic validator which gets 2 field names and work with only these 2 fields. To require more than one field you should add this validator for each field.
Use the following code as an idea (I've not test it).
Validator interface
/**
* Validates that field {#code dependFieldName} is not null if
* field {#code fieldName} has value {#code fieldValue}.
**/
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Repeatable(NotNullIfAnotherFieldHasValue.List.class) // only with hibernate-validator >= 6.x
#Constraint(validatedBy = NotNullIfAnotherFieldHasValueValidator.class)
#Documented
public #interface NotNullIfAnotherFieldHasValue {
String fieldName();
String fieldValue();
String dependFieldName();
String message() default "{NotNullIfAnotherFieldHasValue.message}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Documented
#interface List {
NotNullIfAnotherFieldHasValue[] value();
}
}
Validator implementation
/**
* Implementation of {#link NotNullIfAnotherFieldHasValue} validator.
**/
public class NotNullIfAnotherFieldHasValueValidator
implements ConstraintValidator<NotNullIfAnotherFieldHasValue, Object> {
private String fieldName;
private String expectedFieldValue;
private String dependFieldName;
#Override
public void initialize(NotNullIfAnotherFieldHasValue annotation) {
fieldName = annotation.fieldName();
expectedFieldValue = annotation.fieldValue();
dependFieldName = annotation.dependFieldName();
}
#Override
public boolean isValid(Object value, ConstraintValidatorContext ctx) {
if (value == null) {
return true;
}
try {
String fieldValue = BeanUtils.getProperty(value, fieldName);
String dependFieldValue = BeanUtils.getProperty(value, dependFieldName);
if (expectedFieldValue.equals(fieldValue) && dependFieldValue == null) {
ctx.disableDefaultConstraintViolation();
ctx.buildConstraintViolationWithTemplate(ctx.getDefaultConstraintMessageTemplate())
.addNode(dependFieldName)
.addConstraintViolation();
return false;
}
} catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException ex) {
throw new RuntimeException(ex);
}
return true;
}
}
Validator usage example (hibernate-validator >= 6 with Java 8+)
#NotNullIfAnotherFieldHasValue(
fieldName = "status",
fieldValue = "Canceled",
dependFieldName = "fieldOne")
#NotNullIfAnotherFieldHasValue(
fieldName = "status",
fieldValue = "Canceled",
dependFieldName = "fieldTwo")
public class SampleBean {
private String status;
private String fieldOne;
private String fieldTwo;
// getters and setters omitted
}
Validator usage example (hibernate-validator < 6; the old example)
#NotNullIfAnotherFieldHasValue.List({
#NotNullIfAnotherFieldHasValue(
fieldName = "status",
fieldValue = "Canceled",
dependFieldName = "fieldOne"),
#NotNullIfAnotherFieldHasValue(
fieldName = "status",
fieldValue = "Canceled",
dependFieldName = "fieldTwo")
})
public class SampleBean {
private String status;
private String fieldOne;
private String fieldTwo;
// getters and setters omitted
}
Note that validator implementation uses BeanUtils class from commons-beanutils library but you could also use BeanWrapperImpl from Spring Framework.
See also this great answer: Cross field validation with Hibernate Validator (JSR 303)
You should make use of custom DefaultGroupSequenceProvider<T>:
ConditionalValidation.java
// Marker interface
public interface ConditionalValidation {}
MyCustomFormSequenceProvider.java
public class MyCustomFormSequenceProvider
implements DefaultGroupSequenceProvider<MyCustomForm> {
#Override
public List<Class<?>> getValidationGroups(MyCustomForm myCustomForm) {
List<Class<?>> sequence = new ArrayList<>();
// Apply all validation rules from ConditionalValidation group
// only if someField has given value
if ("some value".equals(myCustomForm.getSomeField())) {
sequence.add(ConditionalValidation.class);
}
// Apply all validation rules from default group
sequence.add(MyCustomForm.class);
return sequence;
}
}
MyCustomForm.java
#GroupSequenceProvider(MyCustomFormSequenceProvider.class)
public class MyCustomForm {
private String someField;
#NotEmpty(groups = ConditionalValidation.class)
private String fieldTwo;
#NotEmpty(groups = ConditionalValidation.class)
private String fieldThree;
#NotEmpty
private String fieldAlwaysValidated;
// getters, setters omitted
}
See also related question on this topic.
Here's my take on it, tried to keep it as simple as possible.
The interface:
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Constraint(validatedBy = OneOfValidator.class)
#Documented
public #interface OneOf {
String message() default "{one.of.message}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String[] value();
}
Validation implementation:
public class OneOfValidator implements ConstraintValidator<OneOf, Object> {
private String[] fields;
#Override
public void initialize(OneOf annotation) {
this.fields = annotation.value();
}
#Override
public boolean isValid(Object value, ConstraintValidatorContext context) {
BeanWrapper wrapper = PropertyAccessorFactory.forBeanPropertyAccess(value);
int matches = countNumberOfMatches(wrapper);
if (matches > 1) {
setValidationErrorMessage(context, "one.of.too.many.matches.message");
return false;
} else if (matches == 0) {
setValidationErrorMessage(context, "one.of.no.matches.message");
return false;
}
return true;
}
private int countNumberOfMatches(BeanWrapper wrapper) {
int matches = 0;
for (String field : fields) {
Object value = wrapper.getPropertyValue(field);
boolean isPresent = detectOptionalValue(value);
if (value != null && isPresent) {
matches++;
}
}
return matches;
}
private boolean detectOptionalValue(Object value) {
if (value instanceof Optional) {
return ((Optional) value).isPresent();
}
return true;
}
private void setValidationErrorMessage(ConstraintValidatorContext context, String template) {
context.disableDefaultConstraintViolation();
context
.buildConstraintViolationWithTemplate("{" + template + "}")
.addConstraintViolation();
}
}
Usage:
#OneOf({"stateType", "modeType"})
public class OneOfValidatorTestClass {
private StateType stateType;
private ModeType modeType;
}
Messages:
one.of.too.many.matches.message=Only one of the following fields can be specified: {value}
one.of.no.matches.message=Exactly one of the following fields must be specified: {value}
A different approach would be to create a (protected) getter that returns an object containing all dependent fields. Example:
public class MyBean {
protected String status;
protected String name;
#StatusAndSomethingValidator
protected StatusAndSomething getStatusAndName() {
return new StatusAndSomething(status,name);
}
}
StatusAndSomethingValidator can now access StatusAndSomething.status and StatusAndSomething.something and make a dependent check.
Sample below:
package io.quee.sample.javax;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import javax.validation.ConstraintViolation;
import javax.validation.Valid;
import javax.validation.Validator;
import javax.validation.constraints.Pattern;
import java.util.Set;
/**
* Created By [**Ibrahim Al-Tamimi **](https://www.linkedin.com/in/iloom/)
* Created At **Wednesday **23**, September 2020**
*/
#SpringBootApplication
public class SampleJavaXValidation implements CommandLineRunner {
private final Validator validator;
public SampleJavaXValidation(Validator validator) {
this.validator = validator;
}
public static void main(String[] args) {
SpringApplication.run(SampleJavaXValidation.class, args);
}
#Override
public void run(String... args) throws Exception {
Set<ConstraintViolation<SampleDataCls>> validate = validator.validate(new SampleDataCls(SampleTypes.TYPE_A, null, null));
System.out.println(validate);
}
public enum SampleTypes {
TYPE_A,
TYPE_B;
}
#Valid
public static class SampleDataCls {
private final SampleTypes type;
private final String valueA;
private final String valueB;
public SampleDataCls(SampleTypes type, String valueA, String valueB) {
this.type = type;
this.valueA = valueA;
this.valueB = valueB;
}
public SampleTypes getType() {
return type;
}
public String getValueA() {
return valueA;
}
public String getValueB() {
return valueB;
}
#Pattern(regexp = "TRUE")
public String getConditionalValueA() {
if (type.equals(SampleTypes.TYPE_A)) {
return valueA != null ? "TRUE" : "";
}
return "TRUE";
}
#Pattern(regexp = "TRUE")
public String getConditionalValueB() {
if (type.equals(SampleTypes.TYPE_B)) {
return valueB != null ? "TRUE" : "";
}
return "TRUE";
}
}
}