Support binding indexed values for record class

spring-context/src/main/java/org/springframework/validation/DataBinder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,6 +49,7 @@
 import org.springframework.beans.SimpleTypeConverter;
 import org.springframework.beans.TypeConverter;
 import org.springframework.beans.TypeMismatchException;
+import org.springframework.core.CollectionFactory;
 import org.springframework.core.KotlinDetector;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ResolvableType;
@@ -112,6 +113,7 @@
  * @author Stephane Nicoll
  * @author Kazuki Shimizu
  * @author Sam Brannen
+ * @author Yanming Zhou
  * @see #setAllowedFields
  * @see #setRequiredFields
  * @see #registerCustomEditor
@@ -952,6 +954,19 @@ private Object createObject(ResolvableType objectType, String nestedPath, ValueR
 					ResolvableType type = ResolvableType.forMethodParameter(param);
 					args[i] = createObject(type, paramPath + ".", valueResolver);
 				}
+				else if (value == null && (Collection.class == paramType || List.class.isAssignableFrom(paramType)
+						|| Map.class.isAssignableFrom(paramType)) && hasIndexedValuesFor(paramPath, valueResolver)) {
+					if (Collection.class == paramType) {
+						// CollectionFactory.createCollection() will create LinkedHashSet which doesn't support indexed property path
+						args[i] = new ArrayList<>(16);
+					}
+					else if (List.class.isAssignableFrom(paramType)) {
+						args[i] = CollectionFactory.createCollection(paramType, 16);
+					}
+					else if (Map.class.isAssignableFrom(paramType)) {
+						args[i] = CollectionFactory.createMap(paramType, 16);
+					}
+				}
 				else {
 					try {
 						if (value == null && (param.isOptional() || getBindingResult().hasErrors())) {
@@ -1031,6 +1046,15 @@ private boolean hasValuesFor(String paramPath, ValueResolver resolver) {
 		return false;
 	}
 
+	private boolean hasIndexedValuesFor(String paramPath, ValueResolver resolver) {
+		for (String name : resolver.getNames()) {
+			if (name.startsWith(paramPath + "[")) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	private void validateConstructorArgument(
 			Class<?> constructorClass, String nestedPath, String name, @Nullable Object value) {
 

spring-context/src/test/java/org/springframework/validation/DataBinderConstructTests.java

@@ -17,13 +17,16 @@
 package org.springframework.validation;
 
 import java.beans.ConstructorProperties;
+import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 
 import jakarta.validation.constraints.NotNull;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.MutablePropertyValues;
 import org.springframework.core.ResolvableType;
 import org.springframework.format.support.DefaultFormattingConversionService;
 import org.springframework.lang.Nullable;
@@ -35,6 +38,7 @@
  * Tests for {@link DataBinder} with constructor binding.
  *
  * @author Rossen Stoyanchev
+ * @author Yanming Zhou
  */
 class DataBinderConstructTests {
 
@@ -101,6 +105,24 @@ void dataClassBindingWithConversionError() {
 		assertThat(bindingResult.getFieldValue("param3")).isNull();
 	}
 
+	@Test
+	void recordClassBindingWithIndexedValue() {
+		Map<String, Object> data = Map.of("collection[0]", "test","list[0]", "test", "map[foo]", "bar");
+		MapValueResolver valueResolver = new MapValueResolver(data);
+		DataBinder binder = initDataBinder(RecordClass.class);
+		binder.construct(valueResolver);
+		binder.bind(new MutablePropertyValues(data));
+
+		BindingResult bindingResult = binder.getBindingResult();
+		assertThat(bindingResult.getAllErrors()).hasSize(0);
+
+		RecordClass target = (RecordClass) binder.getTarget();
+		assertThat(target).isNotNull();
+		assertThat(target.collection).hasSize(1).first().isEqualTo("test");
+		assertThat(target.list).hasSize(1).first().isEqualTo("test");
+		assertThat(target.map).hasSize(1).containsEntry("foo", "bar");
+	}
+
 	@SuppressWarnings("SameParameterValue")
 	private static DataBinder initDataBinder(Class<?> targetType) {
 		DataBinder binder = new DataBinder(null);
@@ -191,4 +213,8 @@ public Set<String> getNames() {
 		}
 	}
 
+	record RecordClass(Collection<String> collection, List<String> list, Map<String, String> map) {
+
+	}
+
 }