Align validation metadata handling in PayloadMethodArgumentResolver

Reuses ValidationAnnotationUtils which is slightly optimized for the detection of Spring's Validated annotation now, also to the benefit of common web scenarios.

Closes gh-21852

Author: jhoeller

spring-context/src/main/java/org/springframework/validation/annotation/ValidationAnnotationUtils.java

@@ -26,37 +26,46 @@
  * Mainly for internal use within the framework.
  *
  * @author Christoph Dreis
+ * @author Juergen Hoeller
  * @since 5.3.7
  */
 public abstract class ValidationAnnotationUtils {
 
 	private static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
 
+
 	/**
 	 * Determine any validation hints by the given annotation.
-	 * <p>This implementation checks for {@code @jakarta.validation.Valid},
-	 * Spring's {@link org.springframework.validation.annotation.Validated},
-	 * and custom annotations whose name starts with "Valid".
+	 * <p>This implementation checks for Spring's
+	 * {@link org.springframework.validation.annotation.Validated},
+	 * {@code @jakarta.validation.Valid}, and custom annotations whose
+	 * name starts with "Valid" which may optionally declare validation
+	 * hints through the "value" attribute.
 	 * @param ann the annotation (potentially a validation annotation)
 	 * @return the validation hints to apply (possibly an empty array),
 	 * or {@code null} if this annotation does not trigger any validation
 	 */
 	@Nullable
 	public static Object[] determineValidationHints(Annotation ann) {
+		// Direct presence of @Validated ?
+		if (ann instanceof Validated validated) {
+			return validated.value();
+		}
+		// Direct presence of @Valid ?
 		Class<? extends Annotation> annotationType = ann.annotationType();
-		String annotationName = annotationType.getName();
-		if ("jakarta.validation.Valid".equals(annotationName)) {
+		if ("jakarta.validation.Valid".equals(annotationType.getName())) {
 			return EMPTY_OBJECT_ARRAY;
 		}
+		// Meta presence of @Validated ?
 		Validated validatedAnn = AnnotationUtils.getAnnotation(ann, Validated.class);
 		if (validatedAnn != null) {
-			Object hints = validatedAnn.value();
-			return convertValidationHints(hints);
+			return validatedAnn.value();
 		}
+		// Custom validation annotation ?
 		if (annotationType.getSimpleName().startsWith("Valid")) {
-			Object hints = AnnotationUtils.getValue(ann);
-			return convertValidationHints(hints);
+			return convertValidationHints(AnnotationUtils.getValue(ann));
 		}
+		// No validation triggered
 		return null;
 	}
 

spring-core/src/main/java/org/springframework/core/annotation/AnnotationUtils.java

@@ -1309,8 +1309,8 @@ static Annotation[] synthesizeAnnotationArray(Annotation[] annotations, Annotate
 	 */
 	public static boolean isSynthesizedAnnotation(@Nullable Annotation annotation) {
 		try {
-			return ((annotation != null) && Proxy.isProxyClass(annotation.getClass()) &&
-					(Proxy.getInvocationHandler(annotation) instanceof SynthesizedMergedAnnotationInvocationHandler));
+			return (annotation != null && Proxy.isProxyClass(annotation.getClass()) &&
+					Proxy.getInvocationHandler(annotation) instanceof SynthesizedMergedAnnotationInvocationHandler);
 		}
 		catch (SecurityException ex) {
 			// Security settings disallow reflective access to the InvocationHandler:

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/reactive/PayloadMethodArgumentResolver.java

@@ -33,7 +33,6 @@
 import org.springframework.core.ReactiveAdapter;
 import org.springframework.core.ReactiveAdapterRegistry;
 import org.springframework.core.ResolvableType;
-import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.DecodingException;
 import org.springframework.core.io.buffer.DataBuffer;
@@ -54,17 +53,17 @@
 import org.springframework.validation.BeanPropertyBindingResult;
 import org.springframework.validation.SmartValidator;
 import org.springframework.validation.Validator;
-import org.springframework.validation.annotation.Validated;
+import org.springframework.validation.annotation.ValidationAnnotationUtils;
 
 /**
  * A resolver to extract and decode the payload of a message using a
- * {@link Decoder}, where the payload is expected to be a {@link Publisher} of
- * {@link DataBuffer DataBuffer}.
+ * {@link Decoder}, where the payload is expected to be a {@link Publisher}
+ * of {@link DataBuffer DataBuffer}.
  *
  * <p>Validation is applied if the method argument is annotated with
- * {@code @jakarta.validation.Valid} or
- * {@link org.springframework.validation.annotation.Validated}. Validation
- * failure results in an {@link MethodArgumentNotValidException}.
+ * {@link org.springframework.validation.annotation.Validated} or
+ * {@code @jakarta.validation.Valid}. Validation failure results in an
+ * {@link MethodArgumentNotValidException}.
  *
  * <p>This resolver should be ordered last if {@link #useDefaultResolution} is
  * set to {@code true} since in that case it supports all types and does not
@@ -286,10 +285,8 @@ private Consumer<Object> getValidator(Message<?> message, MethodParameter parame
 			return null;
 		}
 		for (Annotation ann : parameter.getParameterAnnotations()) {
-			Validated validatedAnn = AnnotationUtils.getAnnotation(ann, Validated.class);
-			if (validatedAnn != null || ann.annotationType().getSimpleName().startsWith("Valid")) {
-				Object hints = (validatedAnn != null ? validatedAnn.value() : AnnotationUtils.getValue(ann));
-				Object[] validationHints = (hints instanceof Object[] objectHints ? objectHints : new Object[] {hints});
+			Object[] validationHints = ValidationAnnotationUtils.determineValidationHints(ann);
+			if (validationHints != null) {
 				String name = Conventions.getVariableNameForParameter(parameter);
 				return target -> {
 					BeanPropertyBindingResult bindingResult = new BeanPropertyBindingResult(target, name);

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/PayloadMethodArgumentResolver.java

@@ -20,7 +20,6 @@
 import java.util.Optional;
 
 import org.springframework.core.MethodParameter;
-import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.converter.MessageConversionException;
@@ -38,12 +37,16 @@
 import org.springframework.validation.ObjectError;
 import org.springframework.validation.SmartValidator;
 import org.springframework.validation.Validator;
-import org.springframework.validation.annotation.Validated;
+import org.springframework.validation.annotation.ValidationAnnotationUtils;
 
 /**
  * A resolver to extract and convert the payload of a message using a
- * {@link MessageConverter}. It also validates the payload using a
- * {@link Validator} if the argument is annotated with a Validation annotation.
+ * {@link MessageConverter}.
+ *
+ * <p>Validation is applied if the method argument is annotated with
+ * {@link org.springframework.validation.annotation.Validated} or
+ * {@code @jakarta.validation.Valid}. Validation failure results in an
+ * {@link MethodArgumentNotValidException}.
  *
  * <p>This {@link HandlerMethodArgumentResolver} should be ordered last as it
  * supports all types and does not require the {@link Payload} annotation.
@@ -196,8 +199,6 @@ protected Class<?> resolveTargetClass(MethodParameter parameter, Message<?> mess
 
 	/**
 	 * Validate the payload if applicable.
-	 * <p>The default implementation checks for {@code @jakarta.validation.Valid},
-	 * Spring's {@link Validated}, and custom annotations whose name starts with "Valid".
 	 * @param message the currently processed message
 	 * @param parameter the method parameter
 	 * @param target the target payload object
@@ -208,10 +209,8 @@ protected void validate(Message<?> message, MethodParameter parameter, Object ta
 			return;
 		}
 		for (Annotation ann : parameter.getParameterAnnotations()) {
-			Validated validatedAnn = AnnotationUtils.getAnnotation(ann, Validated.class);
-			if (validatedAnn != null || ann.annotationType().getSimpleName().startsWith("Valid")) {
-				Object hints = (validatedAnn != null ? validatedAnn.value() : AnnotationUtils.getValue(ann));
-				Object[] validationHints = (hints instanceof Object[] objectHints ? objectHints : new Object[] {hints});
+			Object[] validationHints = ValidationAnnotationUtils.determineValidationHints(ann);
+			if (validationHints != null) {
 				BeanPropertyBindingResult bindingResult =
 						new BeanPropertyBindingResult(target, getParameterName(parameter));
 				if (!ObjectUtils.isEmpty(validationHints) && this.validator instanceof SmartValidator sv) {