HV-2127 Make Path implementation not rely on Lists (or other collections)

cdi/src/main/java/org/hibernate/validator/cdi/interceptor/spi/ValidationInterceptor.java

@@ -4,6 +4,7 @@
  */
 package org.hibernate.validator.cdi.interceptor.spi;
 
+import java.io.Serial;
 import java.io.Serializable;
 import java.lang.reflect.Member;
 import java.util.Arrays;
@@ -37,6 +38,7 @@
 @Priority(Interceptor.Priority.PLATFORM_AFTER + 800)
 public class ValidationInterceptor implements Serializable {
 
+	@Serial
 	private static final long serialVersionUID = 604440259030722151L;
 
 	/**

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

@@ -7,6 +7,7 @@
 import static java.util.stream.Collectors.toList;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -53,7 +54,10 @@ public boolean isValid(Collection collection, ConstraintValidatorContext constra
 		if ( constraintValidatorContext instanceof HibernateConstraintValidatorContext ) {
 			constraintValidatorContext.unwrap( HibernateConstraintValidatorContext.class )
 					.addMessageParameter( "duplicates", duplicates.stream().map( String::valueOf ).collect( Collectors.joining( ", " ) ) )
-					.withDynamicPayload( CollectionHelper.toImmutableList( duplicates ) );
+					// We cannot leverage the CollectionHelper.toImmutableList here as it does not allow `null` values.
+					//  User collections may have `null`s in it and those could as well be duplicates
+					//  so let's rely on the Collections.unmodifiableList here which accepts `null` values as long as the underlying collection allows it:
+					.withDynamicPayload( Collections.unmodifiableList( duplicates ) );
 		}
 
 		return false;

engine/src/main/java/org/hibernate/validator/internal/engine/ConstraintViolationImpl.java

@@ -4,6 +4,7 @@
  */
 package org.hibernate.validator.internal.engine;
 
+import java.io.Serial;
 import java.io.Serializable;
 import java.lang.invoke.MethodHandles;
 import java.util.Map;
@@ -24,6 +25,7 @@
 public class ConstraintViolationImpl<T> implements HibernateConstraintViolation<T>, Serializable {
 
 	private static final Log LOG = LoggerFactory.make( MethodHandles.lookup() );
+	@Serial
 	private static final long serialVersionUID = -4970067626703103139L;
 
 	private final String interpolatedMessage;

engine/src/main/java/org/hibernate/validator/internal/engine/ValidatorImpl.java

@@ -38,8 +38,8 @@
 import org.hibernate.validator.internal.engine.groups.Sequence;
 import org.hibernate.validator.internal.engine.groups.ValidationOrder;
 import org.hibernate.validator.internal.engine.groups.ValidationOrderGenerator;
+import org.hibernate.validator.internal.engine.path.ModifiablePath;
 import org.hibernate.validator.internal.engine.path.NodeImpl;
-import org.hibernate.validator.internal.engine.path.PathImpl;
 import org.hibernate.validator.internal.engine.resolver.TraversableResolvers;
 import org.hibernate.validator.internal.engine.validationcontext.BaseBeanValidationContext;
 import org.hibernate.validator.internal.engine.validationcontext.ExecutableValidationContext;
@@ -164,7 +164,7 @@ public final <T> Set<ConstraintViolation<T>> validate(T object, Class<?>... grou
 				validatorScopedContext.getParameterNameProvider(),
 				object,
 				validationContext.getRootBeanMetaData(),
-				PathImpl.createRootPath()
+				ModifiablePath.createRootPath()
 		);
 
 		return validateInContext( validationContext, valueContext, validationOrder );
@@ -184,7 +184,7 @@ public final <T> Set<ConstraintViolation<T>> validateProperty(T object, String p
 			return Collections.emptySet();
 		}
 
-		PathImpl propertyPath = PathImpl.createPathFromString( propertyName );
+		ModifiablePath propertyPath = ModifiablePath.createPathFromString( propertyName );
 		BaseBeanValidationContext<T> validationContext = getValidationContextBuilder().forValidateProperty( rootBeanClass, rootBeanMetaData, object,
 				propertyPath );
 
@@ -211,7 +211,7 @@ public final <T> Set<ConstraintViolation<T>> validateValue(Class<T> beanType, St
 			return Collections.emptySet();
 		}
 
-		PathImpl propertyPath = PathImpl.createPathFromString( propertyName );
+		ModifiablePath propertyPath = ModifiablePath.createPathFromString( propertyName );
 		BaseBeanValidationContext<T> validationContext = getValidationContextBuilder().forValidateValue( beanType, rootBeanMetaData, propertyPath );
 
 		ValidationOrder validationOrder = determineGroupValidationOrder( groups );
@@ -813,7 +813,7 @@ private BeanValueContext<?, Object> buildNewLocalExecutionContext(ValueContext<?
 		return newValueContext;
 	}
 
-	private <T> Set<ConstraintViolation<T>> validateValueInContext(BaseBeanValidationContext<T> validationContext, Object value, PathImpl propertyPath,
+	private <T> Set<ConstraintViolation<T>> validateValueInContext(BaseBeanValidationContext<T> validationContext, Object value, ModifiablePath propertyPath,
 			ValidationOrder validationOrder) {
 		BeanValueContext<?, Object> valueContext = getValueContextForValueValidation( validationContext.getRootBeanClass(), propertyPath );
 		valueContext.setCurrentValidatedValue( value );
@@ -902,7 +902,7 @@ private <T> void validateParametersInContext(ExecutableValidationContext<T> vali
 				validatorScopedContext.getParameterNameProvider(),
 				parameterValues,
 				executableMetaData.getValidatableParametersMetaData(),
-				PathImpl.createPathForExecutable( executableMetaData )
+				ModifiablePath.createPathForExecutable( executableMetaData )
 		);
 
 		groupIterator = validationOrder.getGroupIterator();
@@ -1035,7 +1035,7 @@ private <T> ValueContext<T, Object> getExecutableValueContext(T object, Executab
 				validatorScopedContext.getParameterNameProvider(),
 				object,
 				validatable,
-				PathImpl.createPathForExecutable( executableMetaData )
+				ModifiablePath.createPathForExecutable( executableMetaData )
 		);
 
 		valueContext.setCurrentGroup( group );
@@ -1078,7 +1078,7 @@ private <V, T> void validateReturnValueInContext(ExecutableValidationContext<T>
 					validatorScopedContext.getParameterNameProvider(),
 					value,
 					executableMetaData.getReturnValueMetaData(),
-					PathImpl.createPathForExecutable( executableMetaData )
+					ModifiablePath.createPathForExecutable( executableMetaData )
 			);
 
 			groupIterator = validationOrder.getGroupIterator();
@@ -1184,7 +1184,7 @@ private <T> void validateReturnValueForSingleGroup(BaseBeanValidationContext<T>
 	 * @return Returns an instance of {@code ValueContext} which describes the local validation context associated to
 	 * the given property path.
 	 */
-	private <V> BeanValueContext<?, V> getValueContextForPropertyValidation(BaseBeanValidationContext<?> validationContext, PathImpl propertyPath) {
+	private <V> BeanValueContext<?, V> getValueContextForPropertyValidation(BaseBeanValidationContext<?> validationContext, ModifiablePath propertyPath) {
 		Class<?> clazz = validationContext.getRootBeanClass();
 		BeanMetaData<?> beanMetaData = validationContext.getRootBeanMetaData();
 		Object value = validationContext.getRootBean();
@@ -1262,7 +1262,7 @@ else if ( propertyPathNode.getKey() != null ) {
 	 * the given property path.
 	 */
 	private <V> BeanValueContext<?, V> getValueContextForValueValidation(Class<?> rootBeanClass,
-			PathImpl propertyPath) {
+			ModifiablePath propertyPath) {
 		Class<?> clazz = rootBeanClass;
 		BeanMetaData<?> beanMetaData = null;
 		PropertyMetaData propertyMetaData = null;
@@ -1330,13 +1330,13 @@ private boolean isValidationRequired(BaseBeanValidationContext<?> validationCont
 		);
 	}
 
-	private boolean isReachable(BaseBeanValidationContext<?> validationContext, Object traversableObject, PathImpl path,
+	private boolean isReachable(BaseBeanValidationContext<?> validationContext, Object traversableObject, ModifiablePath path,
 			ConstraintLocationKind constraintLocationKind) {
 		if ( needToCallTraversableResolver( path, constraintLocationKind ) ) {
 			return true;
 		}
 
-		Path pathToObject = PathImpl.createCopyWithoutLeafNode( path );
+		Path pathToObject = ModifiablePath.createCopyWithoutLeafNode( path );
 		try {
 			return validationContext.getTraversableResolver().isReachable(
 					traversableObject,
@@ -1351,7 +1351,7 @@ private boolean isReachable(BaseBeanValidationContext<?> validationContext, Obje
 		}
 	}
 
-	private boolean needToCallTraversableResolver(PathImpl path, ConstraintLocationKind constraintLocationKind) {
+	private boolean needToCallTraversableResolver(ModifiablePath path, ConstraintLocationKind constraintLocationKind) {
 		// as the TraversableResolver interface is designed right now it does not make sense to call it when
 		// there is no traversable object hosting the property to be accessed. For this reason we don't call the resolver
 		// for class level constraints (ElementType.TYPE) or top level method parameters or return values.
@@ -1362,7 +1362,7 @@ private boolean needToCallTraversableResolver(PathImpl path, ConstraintLocationK
 				|| isReturnValueValidation( path );
 	}
 
-	private boolean isCascadeRequired(BaseBeanValidationContext<?> validationContext, Object traversableObject, PathImpl path,
+	private boolean isCascadeRequired(BaseBeanValidationContext<?> validationContext, Object traversableObject, ModifiablePath path,
 			ConstraintLocationKind constraintLocationKind) {
 		if ( needToCallTraversableResolver( path, constraintLocationKind ) ) {
 			return true;
@@ -1373,7 +1373,7 @@ private boolean isCascadeRequired(BaseBeanValidationContext<?> validationContext
 			return false;
 		}
 
-		Path pathToObject = PathImpl.createCopyWithoutLeafNode( path );
+		Path pathToObject = ModifiablePath.createCopyWithoutLeafNode( path );
 		try {
 			return validationContext.getTraversableResolver().isCascadable(
 					traversableObject,
@@ -1392,15 +1392,15 @@ private boolean isClassLevelConstraint(ConstraintLocationKind constraintLocation
 		return ConstraintLocationKind.TYPE.equals( constraintLocationKind );
 	}
 
-	private boolean isCrossParameterValidation(PathImpl path) {
+	private boolean isCrossParameterValidation(ModifiablePath path) {
 		return path.getLeafNode().getKind() == ElementKind.CROSS_PARAMETER;
 	}
 
-	private boolean isParameterValidation(PathImpl path) {
+	private boolean isParameterValidation(ModifiablePath path) {
 		return path.getLeafNode().getKind() == ElementKind.PARAMETER;
 	}
 
-	private boolean isReturnValueValidation(PathImpl path) {
+	private boolean isReturnValueValidation(ModifiablePath path) {
 		return path.getLeafNode().getKind() == ElementKind.RETURN_VALUE;
 	}
 

engine/src/main/java/org/hibernate/validator/internal/engine/constraintvalidation/ComposingConstraintTree.java

@@ -14,7 +14,6 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
-import java.util.Optional;
 import java.util.stream.Collectors;
 
 import jakarta.validation.ConstraintValidator;
@@ -38,7 +37,7 @@
  * @author Guillaume Smet
  * @author Marko Bekhta
  */
-class ComposingConstraintTree<B extends Annotation> extends ConstraintTree<B> {
+final class ComposingConstraintTree<B extends Annotation> extends ConstraintTree<B> {
 
 	private static final Log LOG = LoggerFactory.make( MethodHandles.lookup() );
 
@@ -61,6 +60,23 @@ private <U extends Annotation> ConstraintTree<U> createConstraintTree(Constraint
 		}
 	}
 
+	@Override
+	public boolean validateConstraints(ValidationContext<?> validationContext, ValueContext<?, ?> valueContext) {
+		List<ConstraintValidatorContextImpl> violatedConstraintValidatorContexts = new ArrayList<>( 5 );
+		validateConstraints( validationContext, valueContext, violatedConstraintValidatorContexts );
+		if ( !violatedConstraintValidatorContexts.isEmpty() ) {
+			for ( ConstraintValidatorContextImpl constraintValidatorContext : violatedConstraintValidatorContexts ) {
+				for ( ConstraintViolationCreationContext constraintViolationCreationContext : constraintValidatorContext.getConstraintViolationCreationContexts() ) {
+					validationContext.addConstraintFailure(
+							valueContext, constraintViolationCreationContext, constraintValidatorContext.getConstraintDescriptor()
+					);
+				}
+			}
+			return false;
+		}
+		return true;
+	}
+
 	@Override
 	protected void validateConstraints(ValidationContext<?> validationContext,
 			ValueContext<?, ?> valueContext,
@@ -69,7 +85,7 @@ protected void validateConstraints(ValidationContext<?> validationContext,
 				validationContext, valueContext, violatedConstraintValidatorContexts
 		);
 
-		Optional<ConstraintValidatorContextImpl> violatedLocalConstraintValidatorContext;
+		ConstraintValidatorContextImpl violatedLocalConstraintValidatorContext;
 
 		// After all children are validated the actual ConstraintValidator of the constraint itself is executed
 		if ( mainConstraintNeedsEvaluation( validationContext, violatedConstraintValidatorContexts ) ) {
@@ -103,15 +119,15 @@ protected void validateConstraints(ValidationContext<?> validationContext,
 
 			// We re-evaluate the boolean composition by taking into consideration also the violations
 			// from the local constraintValidator
-			if ( !violatedLocalConstraintValidatorContext.isPresent() ) {
+			if ( violatedLocalConstraintValidatorContext == null ) {
 				compositionResult.setAtLeastOneTrue( true );
 			}
 			else {
 				compositionResult.setAllTrue( false );
 			}
 		}
 		else {
-			violatedLocalConstraintValidatorContext = Optional.empty();
+			violatedLocalConstraintValidatorContext = null;
 		}
 
 		if ( !passesCompositionTypeRequirement( violatedConstraintValidatorContexts, compositionResult ) ) {
@@ -157,7 +173,7 @@ private boolean mainConstraintNeedsEvaluation(ValidationContext<?> validationCon
 	private void prepareFinalConstraintViolations(ValidationContext<?> validationContext,
 			ValueContext<?, ?> valueContext,
 			Collection<ConstraintValidatorContextImpl> violatedConstraintValidatorContexts,
-			Optional<ConstraintValidatorContextImpl> localConstraintValidatorContext) {
+			ConstraintValidatorContextImpl localConstraintValidatorContext) {
 		if ( reportAsSingleViolation() ) {
 			// We clear the current violations list anyway
 			violatedConstraintValidatorContexts.clear();
@@ -166,7 +182,7 @@ private void prepareFinalConstraintViolations(ValidationContext<?> validationCon
 			// violations or not (or if there is no local ConstraintValidator at all).
 			// If not we create a violation
 			// using the error message in the annotation declaration at top level.
-			if ( !localConstraintValidatorContext.isPresent() ) {
+			if ( localConstraintValidatorContext == null ) {
 				violatedConstraintValidatorContexts.add(
 						validationContext.createConstraintValidatorContextFor(
 								descriptor, valueContext.getPropertyPath()
@@ -183,8 +199,8 @@ private void prepareFinalConstraintViolations(ValidationContext<?> validationCon
 		// as checked in test CustomErrorMessage.java
 		// If no violations have been reported from the local ConstraintValidator, or no such validator exists,
 		// then we just add an empty list.
-		if ( localConstraintValidatorContext.isPresent() ) {
-			violatedConstraintValidatorContexts.add( localConstraintValidatorContext.get() );
+		if ( localConstraintValidatorContext != null ) {
+			violatedConstraintValidatorContexts.add( localConstraintValidatorContext );
 		}
 	}
 

engine/src/main/java/org/hibernate/validator/internal/engine/constraintvalidation/ConstraintTree.java

@@ -7,9 +7,7 @@
 import java.lang.annotation.Annotation;
 import java.lang.invoke.MethodHandles;
 import java.lang.reflect.Type;
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
 import java.util.Optional;
 
 import jakarta.validation.ConstraintDeclarationException;
@@ -33,7 +31,7 @@
  * @author Guillaume Smet
  * @author Marko Bekhta
  */
-public abstract class ConstraintTree<A extends Annotation> {
+public abstract sealed class ConstraintTree<A extends Annotation> permits SimpleConstraintTree, ComposingConstraintTree {
 
 	private static final Log LOG = LoggerFactory.make( MethodHandles.lookup() );
 
@@ -68,21 +66,7 @@ public static <U extends Annotation> ConstraintTree<U> of(ConstraintValidatorMan
 		}
 	}
 
-	public final boolean validateConstraints(ValidationContext<?> validationContext, ValueContext<?, ?> valueContext) {
-		List<ConstraintValidatorContextImpl> violatedConstraintValidatorContexts = new ArrayList<>( 5 );
-		validateConstraints( validationContext, valueContext, violatedConstraintValidatorContexts );
-		if ( !violatedConstraintValidatorContexts.isEmpty() ) {
-			for ( ConstraintValidatorContextImpl constraintValidatorContext : violatedConstraintValidatorContexts ) {
-				for ( ConstraintViolationCreationContext constraintViolationCreationContext : constraintValidatorContext.getConstraintViolationCreationContexts() ) {
-					validationContext.addConstraintFailure(
-							valueContext, constraintViolationCreationContext, constraintValidatorContext.getConstraintDescriptor()
-					);
-				}
-			}
-			return false;
-		}
-		return true;
-	}
+	public abstract boolean validateConstraints(ValidationContext<?> validationContext, ValueContext<?, ?> valueContext);
 
 	protected abstract void validateConstraints(ValidationContext<?> validationContext, ValueContext<?, ?> valueContext,
 			Collection<ConstraintValidatorContextImpl> violatedConstraintValidatorContexts);
@@ -168,7 +152,7 @@ private ValidationException getExceptionForNullValidator(Type validatedValueType
 	 * @return an {@link Optional#empty()} if there is no violation or a corresponding {@link ConstraintValidatorContextImpl}
 	 * 		otherwise.
 	 */
-	protected final <V> Optional<ConstraintValidatorContextImpl> validateSingleConstraint(
+	protected final <V> ConstraintValidatorContextImpl validateSingleConstraint(
 			ValueContext<?, ?> valueContext,
 			ConstraintValidatorContextImpl constraintValidatorContext,
 			ConstraintValidator<A, V> validator) {
@@ -187,9 +171,9 @@ protected final <V> Optional<ConstraintValidatorContextImpl> validateSingleConst
 		if ( !isValid ) {
 			//We do not add these violations yet, since we don't know how they are
 			//going to influence the final boolean evaluation
-			return Optional.of( constraintValidatorContext );
+			return constraintValidatorContext;
 		}
-		return Optional.empty();
+		return null;
 	}
 
 	@Override