Use List for violations in ParameterErrors

See gh-29825

Author: rstoyanchev

spring-context/src/main/java/org/springframework/validation/beanvalidation/MethodValidationAdapter.java

@@ -350,7 +350,7 @@ private final class ValueResultBuilder {
 
 		private final List<MessageSourceResolvable> resolvableErrors = new ArrayList<>();
 
-		private final Set<ConstraintViolation<Object>> violations = new LinkedHashSet<>();
+		private final List<ConstraintViolation<Object>> violations = new ArrayList<>();
 
 		public ValueResultBuilder(Object target, MethodParameter parameter, @Nullable Object argument) {
 			this.target = target;
@@ -359,8 +359,8 @@ public ValueResultBuilder(Object target, MethodParameter parameter, @Nullable Ob
 		}
 
 		public void addViolation(ConstraintViolation<Object> violation) {
-			this.violations.add(violation);
 			this.resolvableErrors.add(createMessageSourceResolvable(this.target, this.parameter, violation));
+			this.violations.add(violation);
 		}
 
 		public ParameterValidationResult build() {
@@ -449,8 +449,22 @@ public int compare(ParameterValidationResult result1, ParameterValidationResult
 				Integer containerIndex2 = errors2.getContainerIndex();
 				if (containerIndex1 != null && containerIndex2 != null) {
 					i = Integer.compare(containerIndex1, containerIndex2);
-					return i;
+					if (i != 0) {
+						return i;
+					}
 				}
+				i = compareKeys(errors1, errors2);
+				return i;
+			}
+			return 0;
+		}
+
+		@SuppressWarnings("unchecked")
+		private <E> int compareKeys(ParameterErrors errors1, ParameterErrors errors2) {
+			Object key1 = errors1.getContainerKey();
+			Object key2 = errors2.getContainerKey();
+			if (key1 instanceof Comparable<?> && key2 instanceof Comparable<?>) {
+				return ((Comparable<E>) key1).compareTo((E) key2);
 			}
 			return 0;
 		}

spring-context/src/main/java/org/springframework/validation/beanvalidation/ParameterErrors.java

@@ -16,9 +16,8 @@
 
 package org.springframework.validation.beanvalidation;
 
-import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
-import java.util.Set;
 
 import jakarta.validation.ConstraintViolation;
 
@@ -66,10 +65,10 @@ public class ParameterErrors extends ParameterValidationResult implements Errors
 	 */
 	public ParameterErrors(
 			MethodParameter parameter, @Nullable Object argument, Errors errors,
-			Set<ConstraintViolation<Object>> violations,
+			Collection<ConstraintViolation<Object>> violations,
 			@Nullable Object container, @Nullable Integer index, @Nullable Object key) {
 
-		super(parameter, argument, new ArrayList<>(errors.getAllErrors()), violations);
+		super(parameter, argument, errors.getAllErrors(), violations);
 
 		this.errors = errors;
 		this.container = container;

spring-context/src/main/java/org/springframework/validation/beanvalidation/ParameterValidationResult.java

@@ -16,8 +16,8 @@
 
 package org.springframework.validation.beanvalidation;
 
+import java.util.Collection;
 import java.util.List;
-import java.util.Set;
 
 import jakarta.validation.ConstraintViolation;
 
@@ -51,23 +51,24 @@ public class ParameterValidationResult {
 
 	private final List<MessageSourceResolvable> resolvableErrors;
 
-	private final Set<ConstraintViolation<Object>> violations;
+	private final List<ConstraintViolation<Object>> violations;
 
 
 	/**
 	 * Create a {@code ParameterValidationResult}.
 	 */
 	public ParameterValidationResult(
-			MethodParameter methodParameter, @Nullable Object argument, List<MessageSourceResolvable> errors,
-			Set<ConstraintViolation<Object>> violations) {
+			MethodParameter methodParameter, @Nullable Object argument,
+			Collection<? extends MessageSourceResolvable> resolvableErrors,
+			Collection<ConstraintViolation<Object>> violations) {
 
-		Assert.notNull(methodParameter, "`MethodParameter` is required");
-		Assert.notEmpty(errors, "`resolvableErrors` must not be empty");
+		Assert.notNull(methodParameter, "MethodParameter is required");
+		Assert.notEmpty(resolvableErrors, "`resolvableErrors` must not be empty");
 		Assert.notEmpty(violations, "'violations' must not be empty");
 		this.methodParameter = methodParameter;
 		this.argument = argument;
-		this.resolvableErrors = List.copyOf(errors);
-		this.violations = violations;
+		this.resolvableErrors = List.copyOf(resolvableErrors);
+		this.violations = List.copyOf(violations);
 	}
 
 
@@ -110,9 +111,10 @@ public List<MessageSourceResolvable> getResolvableErrors() {
 	}
 
 	/**
-	 * The violations associated with the method parameter.
+	 * The violations associated with the method parameter, in the same order
+	 * as {@link #getResolvableErrors()}.
 	 */
-	public Set<ConstraintViolation<Object>> getViolations() {
+	public List<ConstraintViolation<Object>> getViolations() {
 		return this.violations;
 	}