I Wanted to create normal spring application (not spring boot or spring mvc) which uses Jakarta Bean Validation framework
<dependency>
<groupId>org.hibernate.validator</groupId>
<artifactId>hibernate-validator</artifactId>
<version>7.0.1.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate.validator</groupId>
<artifactId>hibernate-validator-annotation-processor</artifactId>
<version>7.0.1.Final</version>
</dependency>
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>jakarta.el</artifactId>
<version>4.0.1</version>
</dependency>
<dependency>
<groupId>jakarta.el</groupId>
<artifactId>jakarta.el-api</artifactId>
<version>4.0.0</version>
</dependency>
Tried to use above dependency but unable perform method/constructor argument validation using #NotNull #NotBlank etc.
Example
public TestConstructor(#NotNull #NotBlank final String param1, #NotNull #NotBlank final String param2, #NotNull #NotBlank final String param3) {
...
...
}
...
...
public void testMethod(#NotNull #NotBlank final String param1) {
...
}
I created the below bean and was only able to validate objects manually
#Bean
public Validator validator() {
return Validation.byProvider(HibernateValidator.class).configure().buildValidatorFactory().getValidator();
}
I wanted to perform auto validation of arguments and objects using jakarta bean validation framework (not with javax validation)
I'm faced with this issue too. So i just copied required parts of Spring framework and create my own ValidatorBean with B&W, but actually with only validation.
#Bean(name = "mvcValidator")
public JakartaValidator validatorFactory(AutowireCapableBeanFactory autowireCapableBeanFactory) {
Validator validator = Validation.byDefaultProvider()
.configure()
.messageInterpolator(new ParameterMessageInterpolator())
.constraintValidatorFactory(new JakartaConstraintValidatorFactory(autowireCapableBeanFactory))
.buildValidatorFactory().getValidator();
return new JakartaValidator(validator);
}
public class JakartaConstraintValidatorFactory implements ConstraintValidatorFactory {
private final AutowireCapableBeanFactory autowireCapableBeanFactory;
#Autowired
public JakartaConstraintValidatorFactory(AutowireCapableBeanFactory autowireCapableBeanFactory) {
this.autowireCapableBeanFactory = autowireCapableBeanFactory;
}
#Override
public <T extends ConstraintValidator<?, ?>> T getInstance(Class<T> key) {
return autowireCapableBeanFactory.createBean(key);
}
#Override
public void releaseInstance(ConstraintValidator<?, ?> instance) {
autowireCapableBeanFactory.destroyBean(instance);
}
}
public class JakartaValidator implements Validator {
private static final Set<String> internalAnnotationAttributes = new HashSet<>(4);
static {
internalAnnotationAttributes.add("message");
internalAnnotationAttributes.add("groups");
internalAnnotationAttributes.add("payload");
}
private final jakarta.validation.Validator validator;
public JakartaValidator(jakarta.validation.Validator validator) {
this.validator = validator;
}
public void init() {
}
#Override
public boolean supports(Class<?> clazz) {
return true;
}
#Override
public void validate(Object target, Errors errors) {
processConstraintViolations(validator.validate(target), errors);
}
protected void processConstraintViolations(Set<ConstraintViolation<Object>> violations, Errors errors) {
for (ConstraintViolation<Object> violation : violations) {
String field = determineField(violation);
FieldError fieldError = errors.getFieldError(field);
if (fieldError == null || !fieldError.isBindingFailure()) {
try {
ConstraintDescriptor<?> cd = violation.getConstraintDescriptor();
String errorCode = determineErrorCode(cd);
Object[] errorArgs = getArgumentsForConstraint(errors.getObjectName(), field, cd);
if (errors instanceof BindingResult) {
// Can do custom FieldError registration with invalid value from ConstraintViolation,
// as necessary for Hibernate Validator compatibility (non-indexed set path in field)
BindingResult bindingResult = (BindingResult) errors;
String nestedField = bindingResult.getNestedPath() + field;
if (nestedField.isEmpty()) {
String[] errorCodes = bindingResult.resolveMessageCodes(errorCode);
ObjectError error = new ViolationObjectError(
errors.getObjectName(), errorCodes, errorArgs, violation, this);
bindingResult.addError(error);
} else {
Object rejectedValue = getRejectedValue(field, violation, bindingResult);
String[] errorCodes = bindingResult.resolveMessageCodes(errorCode, field);
FieldError error = new ViolationFieldError(errors.getObjectName(), nestedField,
rejectedValue, errorCodes, errorArgs, violation, this);
bindingResult.addError(error);
}
} else {
// got no BindingResult - can only do standard rejectValue call
// with automatic extraction of the current field value
errors.rejectValue(field, errorCode, errorArgs, violation.getMessage());
}
} catch (NotReadablePropertyException ex) {
throw new IllegalStateException("JSR-303 validated property '" + field +
"' does not have a corresponding accessor for Spring data binding - " +
"check your DataBinder's configuration (bean property versus direct field access)", ex);
}
}
}
}
#Nullable
protected Object getRejectedValue(String field, ConstraintViolation<Object> violation, BindingResult bindingResult) {
Object invalidValue = violation.getInvalidValue();
if (field != null && !field.isEmpty() && !field.contains("[]") &&
(invalidValue == violation.getLeafBean() || field.contains("[") || field.contains("."))) {
// Possibly a bean constraint with property path: retrieve the actual property value.
// However, explicitly avoid this for "address[]" style paths that we can't handle.
invalidValue = bindingResult.getRawFieldValue(field);
}
return invalidValue;
}
protected String determineField(ConstraintViolation<Object> violation) {
Path path = violation.getPropertyPath();
StringBuilder sb = new StringBuilder();
boolean first = true;
for (Path.Node node : path) {
if (node.isInIterable()) {
sb.append('[');
Object index = node.getIndex();
if (index == null) {
index = node.getKey();
}
if (index != null) {
sb.append(index);
}
sb.append(']');
}
String name = node.getName();
if (name != null && node.getKind() == ElementKind.PROPERTY && !name.startsWith("<")) {
if (!first) {
sb.append('.');
}
first = false;
sb.append(name);
}
}
return sb.toString();
}
protected String determineErrorCode(ConstraintDescriptor<?> descriptor) {
return descriptor.getAnnotation().annotationType().getSimpleName();
}
protected Object[] getArgumentsForConstraint(String objectName, String field, ConstraintDescriptor<?> descriptor) {
List<Object> arguments = new ArrayList<>();
arguments.add(getResolvableField(objectName, field));
// Using a TreeMap for alphabetical ordering of attribute names
Map<String, Object> attributesToExpose = new TreeMap<>();
descriptor.getAttributes().forEach((attributeName, attributeValue) -> {
if (!internalAnnotationAttributes.contains(attributeName)) {
if (attributeValue instanceof String) {
attributeValue = new ResolvableAttribute(attributeValue.toString());
}
attributesToExpose.put(attributeName, attributeValue);
}
});
arguments.addAll(attributesToExpose.values());
return arguments.toArray();
}
protected MessageSourceResolvable getResolvableField(String objectName, String field) {
String[] codes = {objectName + Errors.NESTED_PATH_SEPARATOR + field, field};
return new DefaultMessageSourceResolvable(codes, field);
}
protected boolean requiresMessageFormat(ConstraintViolation<?> violation) {
return containsSpringStylePlaceholder(violation.getMessage());
}
private static boolean containsSpringStylePlaceholder(#Nullable String message) {
return (message != null && message.contains("{0}"));
}
private static class ResolvableAttribute implements MessageSourceResolvable, Serializable {
private final String resolvableString;
public ResolvableAttribute(String resolvableString) {
this.resolvableString = resolvableString;
}
#Override
public String[] getCodes() {
return new String[]{this.resolvableString};
}
#Override
#Nullable
public Object[] getArguments() {
return null;
}
#Override
public String getDefaultMessage() {
return this.resolvableString;
}
#Override
public String toString() {
return this.resolvableString;
}
}
private static class ViolationObjectError extends ObjectError implements Serializable {
#Nullable
private final transient JakartaValidator adapter;
#Nullable
private final transient ConstraintViolation<?> violation;
public ViolationObjectError(String objectName, String[] codes, Object[] arguments,
ConstraintViolation<?> violation, JakartaValidator adapter) {
super(objectName, codes, arguments, violation.getMessage());
this.adapter = adapter;
this.violation = violation;
wrap(violation);
}
#Override
public boolean shouldRenderDefaultMessage() {
return (this.adapter != null && this.violation != null ?
this.adapter.requiresMessageFormat(this.violation) :
containsSpringStylePlaceholder(getDefaultMessage()));
}
}
private static class ViolationFieldError extends FieldError implements Serializable {
#Nullable
private final transient JakartaValidator adapter;
#Nullable
private final transient ConstraintViolation<?> violation;
public ViolationFieldError(String objectName, String field, #Nullable Object rejectedValue, String[] codes,
Object[] arguments, ConstraintViolation<?> violation, JakartaValidator adapter) {
super(objectName, field, rejectedValue, false, codes, arguments, violation.getMessage());
this.adapter = adapter;
this.violation = violation;
wrap(violation);
}
#Override
public boolean shouldRenderDefaultMessage() {
return (this.adapter != null && this.violation != null ?
this.adapter.requiresMessageFormat(this.violation) :
containsSpringStylePlaceholder(getDefaultMessage()));
}
}
}
I was following this tutorial for create a custom validation with multiple parameters, but I get the following exception when executing the #PostMapping method:
HV000030: No validator could be found for constraint 'com.crimsonlogic.anotaciones.TimeRangeConstraints' validating type 'com.crimsonlogic.model.NuevoEvento'. Check configuration for ''
it catches my attention that at the "check configuration for ''" part, does not tell me any kind of information.
NuevoEvento class:
#TimeRangeConstraints.List({
#TimeRangeConstraints(
fechaEvento="fechaEvento",
horaInicio="horaInicio",
horaCulminacion="horaCulminacion"
)
})
public class NuevoEvento {
#NotNull(message="Como se llamara el evento?")
#Size(max=40, message="Titulo invalido")
private String titulo;
#NotNull(message="Seleccione un tipo.")
private String tipoEvento;
private String url;
#NotNull(message="Seleccione la fecha del evento")
private String fechaEvento;
#NotNull(message="A que hora inicia el evento?")
private String horaInicio;
#NotBlank(message="A que hora termina el evento?")
private String horaCulminacion;
#NotNull(message="Seleccione un salon.")
private int salonId;
public NuevoEvento() {}
public String getTitulo() {
return titulo;
}
public void setTitulo(String titulo) {
this.titulo = titulo;
}
public String getTipoEvento() {
return tipoEvento;
}
public void setTipoEvento(String tipoEvento) {
this.tipoEvento = tipoEvento;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getFechaEvento() {
return fechaEvento;
}
public void setFechaEvento(String fechaEvento) {
this.fechaEvento = fechaEvento;
}
public String getHoraInicio() {
return horaInicio;
}
public void setHoraInicio(String horaInicio) {
this.horaInicio = horaInicio;
}
public String getHoraCulminacion() {
return horaCulminacion;
}
public void setHoraCulminacion(String horaCulminacion) {
this.horaCulminacion = horaCulminacion;
}
public int getSalonId() {
return salonId;
}
public void setSalon(int salon) {
this.salonId = salon;
}
}
TimeRangeConstraint annotation:
#Documented
#Target({ElementType.TYPE})
#Retention(RetentionPolicy.RUNTIME)
#Constraint(validatedBy= TimeRangeValidator.class)
public #interface TimeRangeConstraints {
String fechaEvento();
String horaInicio();
String horaCulminacion();
String message() default "El rango de tiempo establecido no es valido o esta ocupado.";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
#Target({ElementType.TYPE})
#Retention(RetentionPolicy.RUNTIME)
#interface List {
TimeRangeConstraints[] value();
}
}
Anyone knows causes of this problem?
I found the problem.
In my TimeRangeValidator class I had the code as follows:
//HERE WAS THE PROBLEM
public class TimeRangeValidator implements ConstraintValidator<TimeRangeConstraints,String> {
//--------------------------------------------------------------------------------->
private String fechaEvento;
private String horaInicial;
private String horaFinal;
#Autowired
private UsuarioSalonRepository usuarioSalon;
#Override
public void initialize(TimeRangeConstraints constraintAnnotation) {
this.fechaEvento = constraintAnnotation.fechaEvento();
this.horaInicial = constraintAnnotation.horaInicio();
this.horaFinal = constraintAnnotation.horaCulminacion();
}
//// MORE AND MOREEE CODE....////
I had to replace the String with Object
public class TimeRangeValidator implements ConstraintValidator<TimeRangeConstraints,Object>
and the problem disappeared.
Deeper explanation for those who did not understand what happened
TimeRangeValidator takes 3 fields from the form to perform the validation logic. The value that was changed previously prevented me from taking the 3 fields of the form due to the following reason:
#Override
public boolean isValid(Object value, ConstraintValidatorContext context) {
Object dt = new BeanWrapperImpl(value).getPropertyValue(fechaEvento);
Object hInit = new BeanWrapperImpl(value).getPropertyValue(horaInicial);
Object hFin = new BeanWrapperImpl(value).getPropertyValue(horaFinal);
SimpleDateFormat form = new SimpleDateFormat("yyyy-MM-dd");
try {
Date dia = form.parse(dt.toString().replaceAll("/","-"));
return TimeUtils.detectOverlappingEvents(usuarioSalon.buscarEvento(dia),
hInit.toString().replaceAll("\\s","")+":00",
hFin.toString().replaceAll("\\s","")+":00");
} catch (ParseException e) {
e.printStackTrace();
return false;
}
With the type object I can have the ability (with the help of BeanWrapperImpl) to obtain multiple values of the form to validate them.
Normally, type String (or Integer, whatever) is used to validate a single value of the form.
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;
}