HV-1466: UniqueElements constraint

annotation-processor/src/main/java/org/hibernate/validator/ap/internal/util/ConstraintHelper.java

@@ -303,6 +303,7 @@ public ConstraintHelper(Types typeUtils, AnnotationApiHelper annotationApiHelper
 		registerAllowedTypesForBuiltInConstraint( HibernateValidatorTypes.NOT_EMPTY, TYPES_SUPPORTED_BY_SIZE_AND_NOT_EMPTY_ANNOTATIONS );
 		registerAllowedTypesForBuiltInConstraint( HibernateValidatorTypes.SAFE_HTML, CharSequence.class );
 		registerAllowedTypesForBuiltInConstraint( HibernateValidatorTypes.SCRIPT_ASSERT, Object.class );
+		registerAllowedTypesForBuiltInConstraint( HibernateValidatorTypes.UNIQUE_ELEMENTS, Collection.class );
 		registerAllowedTypesForBuiltInConstraint( HibernateValidatorTypes.URL, CharSequence.class );
 
 		registerSupportedTypesUnwrappedByDefault( SupportedForUnwrapTypes.OPTIONAL_INT, Integer.class.getName() );

annotation-processor/src/main/java/org/hibernate/validator/ap/internal/util/TypeNames.java

@@ -80,6 +80,7 @@ public static class HibernateValidatorTypes {
 		public static final String NOT_EMPTY = ORG_HIBERNATE_VALIDATOR_CONSTRAINTS + ".NotEmpty";
 		public static final String SAFE_HTML = ORG_HIBERNATE_VALIDATOR_CONSTRAINTS + ".SafeHtml";
 		public static final String SCRIPT_ASSERT = ORG_HIBERNATE_VALIDATOR_CONSTRAINTS + ".ScriptAssert";
+		public static final String UNIQUE_ELEMENTS = ORG_HIBERNATE_VALIDATOR_CONSTRAINTS + ".UniqueElements";
 		public static final String URL = ORG_HIBERNATE_VALIDATOR_CONSTRAINTS + ".URL";
 		public static final String DURATION_MIN = ORG_HIBERNATE_VALIDATOR_CONSTRAINTS + ".time.DurationMin";
 		public static final String DURATION_MAX = ORG_HIBERNATE_VALIDATOR_CONSTRAINTS + ".time.DurationMax";

annotation-processor/src/test/java/org/hibernate/validator/ap/ConstraintValidationProcessorTest.java

@@ -24,6 +24,7 @@
 import org.hibernate.validator.ap.testmodel.ModelWithJava8DateTime;
 import org.hibernate.validator.ap.testmodel.ModelWithJavaMoneyTypes;
 import org.hibernate.validator.ap.testmodel.ModelWithJodaTypes;
+import org.hibernate.validator.ap.testmodel.ModelWithUniqueElementsConstraints;
 import org.hibernate.validator.ap.testmodel.ModelWithoutConstraints;
 import org.hibernate.validator.ap.testmodel.MultipleConstraintsOfSameType;
 import org.hibernate.validator.ap.testmodel.ValidationUsingAtValidAnnotation;
@@ -685,4 +686,21 @@ public void unwrappingConstraints() {
 				new DiagnosticExpectation( Kind.WARNING, 54 )
 		);
 	}
+
+	@Test
+	@TestForIssue(jiraKey = "HV-1466")
+	public void uniqueElementsConstraints() {
+		File[] sourceFiles = new File[] {
+				compilerHelper.getSourceFile( ModelWithUniqueElementsConstraints.class )
+		};
+
+		boolean compilationResult =
+				compilerHelper.compile( new ConstraintValidationProcessor(), diagnostics, false, true, sourceFiles );
+
+		assertFalse( compilationResult );
+		assertThatDiagnosticsMatch(
+				diagnostics,
+				new DiagnosticExpectation( Kind.ERROR, 26 )
+		);
+	}
 }

annotation-processor/src/test/java/org/hibernate/validator/ap/testmodel/ModelWithUniqueElementsConstraints.java

@@ -0,0 +1,28 @@
+/*
+ * Hibernate Validator, declare and validate application constraints
+ *
+ * License: Apache License, Version 2.0
+ * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
+ */
+package org.hibernate.validator.ap.testmodel;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+import org.hibernate.validator.constraints.UniqueElements;
+
+public class ModelWithUniqueElementsConstraints {
+
+	@UniqueElements
+	public Collection<String> collection;
+
+	@UniqueElements
+	public List<String> list;
+
+	@UniqueElements
+	public Set<String> set;
+
+	@UniqueElements
+	public String string;
+}

documentation/src/main/asciidoc/ch02.asciidoc

@@ -716,6 +716,10 @@ In addition, `baseURI` allows to specify the base URI used to resolve relative U
 	Supported data types::: Any type
 	Hibernate metadata impact::: None
 
+`@UniqueElements`:: Checks that the annotated collection only contains unique elements. The equality is determined using the `equals()` method. The default message does not include the list of duplicate elements but you can include it by overriding the message and using the `{duplicates}` message parameter. The list of duplicate elements is also included in the dynamic payload of the constraint violation.
+	Supported data types::: `Collection`
+	Hibernate metadata impact::: None
+
 `@URL(protocol=, host=, port=, regexp=, flags=)`:: Checks if the annotated character sequence is a valid URL according to RFC2396. If any of the optional parameters `protocol`, `host` or `port` are specified, the corresponding URL fragments must match the specified values. The optional parameters `regexp` and `flags` allow to specify an additional regular expression (including regular expression flags) which the URL must match. Per default this constraint used the `java.net.URL` constructor to verify whether a given string represents a valid URL. A regular expression based version is also available - `RegexpURLValidator` - which can be configured via XML (see <<section-mapping-xml-constraints>>) or the programmatic API (see <<section-programmatic-constraint-definition>>).
 	Supported data types::: `CharSequence`
 	Hibernate metadata impact::: None

engine/src/main/java/org/hibernate/validator/cfg/defs/UniqueElementsDef.java

@@ -0,0 +1,22 @@
+/*
+ * Hibernate Validator, declare and validate application constraints
+ *
+ * License: Apache License, Version 2.0
+ * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
+ */
+
+package org.hibernate.validator.cfg.defs;
+
+import org.hibernate.validator.cfg.ConstraintDef;
+import org.hibernate.validator.constraints.UniqueElements;
+
+/**
+ * @author Guillaume Smet
+ * @since 6.0.5
+ */
+public class UniqueElementsDef extends ConstraintDef<UniqueElementsDef, UniqueElements> {
+
+	public UniqueElementsDef() {
+		super( UniqueElements.class );
+	}
+}

engine/src/main/java/org/hibernate/validator/constraints/UniqueElements.java

@@ -0,0 +1,62 @@
+/*
+ * Hibernate Validator, declare and validate application constraints
+ *
+ * License: Apache License, Version 2.0
+ * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
+ */
+package org.hibernate.validator.constraints;
+
+import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
+import static java.lang.annotation.ElementType.CONSTRUCTOR;
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.ElementType.TYPE_USE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Repeatable;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+import java.util.Collection;
+
+import javax.validation.Constraint;
+import javax.validation.Payload;
+
+import org.hibernate.validator.constraints.UniqueElements.List;
+
+/**
+ * Validates that every object in the provided {@link Collection} is unique, i.e. that we can't find 2 equal elements in
+ * the collection.
+ * <p>
+ * For instance, this can be useful with JAX-RS, which always deserializes collections to a list. Thus, duplicates would
+ * implicitly and silently be removed when converting it to a set. This constraint allows you to check for duplicates in
+ * the list and to raise an error instead.
+ *
+ * @author Tadhg Pearson
+ * @since 6.0.5
+ */
+@Documented
+@Constraint(validatedBy = { })
+@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE })
+@Retention(RUNTIME)
+@Repeatable(List.class)
+public @interface UniqueElements {
+
+	String message() default "{org.hibernate.validator.constraints.UniqueElements.message}";
+
+	Class<?>[] groups() default {};
+
+	Class<? extends Payload>[] payload() default {};
+
+	/**
+	 * Defines several {@code @UniqueElements} annotations on the same element.
+	 */
+	@Target({ TYPE })
+	@Retention(RUNTIME)
+	@Documented
+	public @interface List {
+		UniqueElements[] value();
+	}
+}

engine/src/main/java/org/hibernate/validator/internal/constraintvalidators/hv/UniqueElementsValidator.java

@@ -0,0 +1,66 @@
+/*
+ * Hibernate Validator, declare and validate application constraints
+ *
+ * License: Apache License, Version 2.0
+ * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
+ */
+package org.hibernate.validator.internal.constraintvalidators.hv;
+
+import static java.util.stream.Collectors.toList;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import javax.validation.ConstraintValidator;
+import javax.validation.ConstraintValidatorContext;
+
+import org.hibernate.validator.constraints.UniqueElements;
+import org.hibernate.validator.constraintvalidation.HibernateConstraintValidatorContext;
+import org.hibernate.validator.internal.util.CollectionHelper;
+
+/**
+ * Validates that the provided collection only contains unique elements, i.e. that we can't find 2 equal elements in the
+ * collection.
+ * <p>
+ * Uniqueness is defined by the {@code equals()} method of the objects being compared.
+ *
+ * @author Tadhg Pearson
+ * @author Guillaume Smet
+ */
+public class UniqueElementsValidator implements ConstraintValidator<UniqueElements, Collection<?>> {
+
+	/**
+	 * @param collection the collection to validate
+	 * @param constraintValidatorContext context in which the constraint is evaluated
+	 *
+	 * @return true if the input collection is null or does not contain duplicate elements
+	 */
+	@Override
+	public boolean isValid(Collection<?> collection, ConstraintValidatorContext constraintValidatorContext) {
+		if ( collection == null || collection.size() < 2 ) {
+			return true;
+		}
+
+		List<Object> duplicates = findDuplicates( collection );
+
+		if ( duplicates.isEmpty() ) {
+			return true;
+		}
+
+		if ( constraintValidatorContext instanceof HibernateConstraintValidatorContext ) {
+			constraintValidatorContext.unwrap( HibernateConstraintValidatorContext.class )
+					.addMessageParameter( "duplicates", duplicates.stream().map( String::valueOf ).collect( Collectors.joining( ", " ) ) )
+					.withDynamicPayload( CollectionHelper.toImmutableList( duplicates ) );
+		}
+
+		return false;
+	}
+
+	private List<Object> findDuplicates(Collection<?> collection) {
+		Set<Object> uniqueElements = CollectionHelper.newHashSet( collection.size() );
+		return collection.stream().filter( o -> !uniqueElements.add( o ) )
+				.collect( toList() );
+	}
+}

engine/src/main/java/org/hibernate/validator/internal/metadata/core/ConstraintHelper.java

@@ -66,6 +66,7 @@
 import org.hibernate.validator.constraints.SafeHtml;
 import org.hibernate.validator.constraints.ScriptAssert;
 import org.hibernate.validator.constraints.URL;
+import org.hibernate.validator.constraints.UniqueElements;
 import org.hibernate.validator.constraints.br.CNPJ;
 import org.hibernate.validator.constraints.br.CPF;
 import org.hibernate.validator.constraints.pl.NIP;
@@ -262,6 +263,7 @@
 import org.hibernate.validator.internal.constraintvalidators.hv.SafeHtmlValidator;
 import org.hibernate.validator.internal.constraintvalidators.hv.ScriptAssertValidator;
 import org.hibernate.validator.internal.constraintvalidators.hv.URLValidator;
+import org.hibernate.validator.internal.constraintvalidators.hv.UniqueElementsValidator;
 import org.hibernate.validator.internal.constraintvalidators.hv.br.CNPJValidator;
 import org.hibernate.validator.internal.constraintvalidators.hv.br.CPFValidator;
 import org.hibernate.validator.internal.constraintvalidators.hv.pl.NIPValidator;
@@ -667,6 +669,7 @@ public ConstraintHelper() {
 		putConstraint( tmpConstraints, ParameterScriptAssert.class, ParameterScriptAssertValidator.class );
 		putConstraint( tmpConstraints, SafeHtml.class, SafeHtmlValidator.class );
 		putConstraint( tmpConstraints, ScriptAssert.class, ScriptAssertValidator.class );
+		putConstraint( tmpConstraints, UniqueElements.class, UniqueElementsValidator.class );
 		putConstraint( tmpConstraints, URL.class, URLValidator.class );
 
 		this.builtinConstraints = Collections.unmodifiableMap( tmpConstraints );

engine/src/main/resources/org/hibernate/validator/ValidationMessages.properties

@@ -37,6 +37,7 @@ org.hibernate.validator.constraints.ParametersScriptAssert.message  = script exp
 org.hibernate.validator.constraints.Range.message                   = must be between {min} and {max}
 org.hibernate.validator.constraints.SafeHtml.message                = may have unsafe html content
 org.hibernate.validator.constraints.ScriptAssert.message            = script expression "{script}" didn't evaluate to true
+org.hibernate.validator.constraints.UniqueElements.message          = must only contain unique elements
 org.hibernate.validator.constraints.URL.message                     = must be a valid URL
 
 org.hibernate.validator.constraints.br.CNPJ.message                 = invalid Brazilian corporate taxpayer registry number (CNPJ)

engine/src/main/resources/org/hibernate/validator/ValidationMessages_de.properties

@@ -33,6 +33,7 @@ org.hibernate.validator.constraints.ParametersScriptAssert.message = Skriptausdr
 org.hibernate.validator.constraints.Range.message            = muss zwischen {min} und {max} liegen
 org.hibernate.validator.constraints.SafeHtml.message         = k\u00F6nnte unsicheren HTML-Inhalt haben
 org.hibernate.validator.constraints.ScriptAssert.message     = Skriptausdruck "{script}" gab nicht true zur\u00FCck
+org.hibernate.validator.constraints.UniqueElements.message   = darf keine Duplikate enthalten
 org.hibernate.validator.constraints.URL.message              = muss eine g\u00FCltige URL sein
 
 org.hibernate.validator.constraints.time.DurationMax.message        = muss k\u00FCrzer${inclusive == true ? ' oder gleich' : ' als'}${days == 0 ? '' : days == 1 ? ' 1 Tag' : ' ' += days += ' Tage'}${hours == 0 ? '' : hours == 1 ? ' 1 Stunde' : ' ' += hours += ' Stunden'}${minutes == 0 ? '' : minutes == 1 ? ' 1 Minute' : ' ' += minutes += ' Minuten'}${seconds == 0 ? '' : seconds == 1 ? ' 1 Sekunde' : ' ' += seconds += ' Sekunden'}${millis == 0 ? '' : millis == 1 ? ' 1 Millisekunde' : ' ' += millis += ' Millisekunden'}${nanos == 0 ? '' : nanos == 1 ? ' 1 Nanosekunde' : ' ' += nanos += ' Nanosekunden'} sein

engine/src/main/resources/org/hibernate/validator/ValidationMessages_fr.properties

@@ -37,6 +37,7 @@ org.hibernate.validator.constraints.ParametersScriptAssert.message  = le script
 org.hibernate.validator.constraints.Range.message            = doit \u00EAtre entre {min} et {max}
 org.hibernate.validator.constraints.SafeHtml.message         = peut contenir du HTML dangereux
 org.hibernate.validator.constraints.ScriptAssert.message     = le script "{script}" n'a pas \u00E9t\u00E9 \u00E9valu\u00E9 \u00E0 vrai
+org.hibernate.validator.constraints.UniqueElements.message   = ne doit contenir que des \u00E9l\u00E9ments uniques
 org.hibernate.validator.constraints.URL.message              = URL mal form\u00E9e
 
 org.hibernate.validator.constraints.br.CNPJ.message                 = numéro d'enregistrement brésilien de société contribuable (CNPJ) invalide

engine/src/main/resources/org/hibernate/validator/ValidationMessages_uk.properties

@@ -37,6 +37,7 @@ org.hibernate.validator.constraints.ParametersScriptAssert.message  = \u0441\u04
 org.hibernate.validator.constraints.Range.message                   = \u043c\u0430\u0454 \u0431\u0443\u0442\u0438 \u043c\u0456\u0436 {min} \u0442\u0430 {max}
 org.hibernate.validator.constraints.SafeHtml.message                = \u043c\u043e\u0436\u0435 \u043c\u0456\u0441\u0442\u0438\u0442\u0438 \u043d\u0435\u0431\u0435\u0437\u043f\u0435\u0447\u043d\u0438\u0439 html \u043a\u043e\u043d\u0442\u0435\u043d\u0442
 org.hibernate.validator.constraints.ScriptAssert.message            = \u0441\u043a\u0440\u0438\u043f\u0442\u043e\u0432\u0438\u0439 \u0432\u0438\u0440\u0430\u0437 "{script}" \u043d\u0435 \u0454 \u0456\u0441\u0442\u0438\u043d\u043d\u0438\u043c
+org.hibernate.validator.constraints.UniqueElements.message          = \u043f\u043e\u0432\u0438\u043d\u043d\u043e \u043c\u0456\u0441\u0442\u0438\u0442\u0438 \u043b\u0438\u0448\u0435 \u0443\u043d\u0456\u043a\u0430\u043b\u044c\u043d\u0456 \u0435\u043b\u0435\u043c\u0435\u043d\u0442\u0438
 org.hibernate.validator.constraints.URL.message                     = \u043c\u0430\u0454 \u0431\u0443\u0442\u0438 \u0434\u0456\u0439\u0441\u043d\u0438\u043c URL
 
 org.hibernate.validator.constraints.br.CNPJ.message                 = \u043d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u0438\u0439 \u043d\u043e\u043c\u0435\u0440 \u0431\u0440\u0430\u0437\u0438\u043b\u044c\u0441\u043a\u043e\u0433\u043e \u043a\u043e\u0440\u043f\u043e\u0440\u0430\u0442\u0438\u0432\u043d\u043e\u0433\u043e \u043f\u043b\u0430\u0442\u043d\u0438\u043a\u0430 \u043f\u043e\u0434\u0430\u0442\u043a\u0456\u0432 (CNPJ)

engine/src/test/java/org/hibernate/validator/test/cfg/UniqueElementsDefTest.java

@@ -0,0 +1,62 @@
+/*
+ * Hibernate Validator, declare and validate application constraints
+ *
+ * License: Apache License, Version 2.0
+ * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
+ */
+package org.hibernate.validator.test.cfg;
+
+import static org.hibernate.validator.testutil.ConstraintViolationAssert.assertThat;
+import static org.hibernate.validator.testutil.ConstraintViolationAssert.violationOf;
+
+import java.lang.annotation.ElementType;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.Validator;
+
+import org.hibernate.validator.HibernateValidator;
+import org.hibernate.validator.HibernateValidatorConfiguration;
+import org.hibernate.validator.cfg.ConstraintMapping;
+import org.hibernate.validator.cfg.defs.UniqueElementsDef;
+import org.hibernate.validator.constraints.UniqueElements;
+import org.hibernate.validator.testutil.TestForIssue;
+import org.hibernate.validator.testutils.ValidatorUtil;
+import org.testng.annotations.Test;
+
+/**
+ * @author Guillaume Smet
+ */
+public class UniqueElementsDefTest {
+
+	@Test
+	@TestForIssue(jiraKey = "HV-1466")
+	public void testUniqueItemsDef() {
+		final HibernateValidatorConfiguration configuration = ValidatorUtil.getConfiguration( HibernateValidator.class );
+
+		final ConstraintMapping programmaticMapping = configuration.createConstraintMapping();
+		programmaticMapping.type( Library.class )
+				.property( "books", ElementType.FIELD ).constraint( new UniqueElementsDef() );
+		configuration.addMapping( programmaticMapping );
+
+		Validator validator = configuration.buildValidatorFactory().getValidator();
+		Set<ConstraintViolation<Library>> violations = validator.validate( new Library(
+				Arrays.asList( "A Prayer for Owen Meany", "The Cider House Rules", "The Cider House Rules" ) ) );
+
+		assertThat( violations ).containsOnlyViolations(
+				violationOf( UniqueElements.class ).withProperty( "books" )
+		);
+	}
+
+	@SuppressWarnings("unused")
+	private static class Library {
+
+		private final List<String> books;
+
+		public Library(List<String> books) {
+			this.books = books;
+		}
+	}
+}