Support @Validated at method level for overriding validation groups

Issue: SPR-9174

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -35,7 +35,11 @@ import java.lang.annotation.Target;
  * class is supposed to be validated at the method level (acting as a pointcut
  * for the corresponding validation interceptor), but also optionally specifying
  * the validation groups for method-level validation in the annotated class.
- * Can also be used as a meta-annotation on a custom stereotype annotation.
+ * Applying this annotation at the method level allows for overriding the
+ * validation groups for a specific method but does not serve as a pointcut;
+ * a class-level annotation is nevertheless necessary to trigger method validation
+ * for a specific bean to begin with. Can also be used as a meta-annotation on a
+ * custom stereotype annotation or a custom group-specific validated annotation.
  *
  * @author Juergen Hoeller
  * @since 3.1
@@ -44,7 +48,7 @@ import java.lang.annotation.Target;
  * @see org.springframework.validation.beanvalidation.SpringValidatorAdapter
  * @see org.springframework.validation.beanvalidation.MethodValidationPostProcessor
  */
-@Target({ElementType.TYPE, ElementType.PARAMETER})
+@Target({ElementType.TYPE, ElementType.METHOD, ElementType.PARAMETER})
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 public @interface Validated {

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

@@ -141,8 +141,11 @@ public class MethodValidationInterceptor implements MethodInterceptor {
 	 * @return the applicable validation groups as a Class array
 	 */
 	protected Class<?>[] determineValidationGroups(MethodInvocation invocation) {
-		Validated valid = AnnotationUtils.findAnnotation(invocation.getThis().getClass(), Validated.class);
+		Validated validatedAnn = AnnotationUtils.findAnnotation(invocation.getMethod(), Validated.class);
-		return (valid != null ? valid.value() : new Class<?>[0]);
+		if (validatedAnn == null) {
+			validatedAnn = AnnotationUtils.findAnnotation(invocation.getThis().getClass(), Validated.class);
+		}
+		return (validatedAnn != null ? validatedAnn.value() : new Class<?>[0]);
 	}
 
 

spring-context/src/test/java/org/springframework/validation/beanvalidation/MethodValidationTests.java

@@ -124,7 +124,8 @@ public class MethodValidationTests {
 
 		@NotNull Object myValidMethod(@NotNull(groups = MyGroup.class) String arg1, @Max(10) int arg2);
 
-		@Async void myValidAsyncMethod(@NotNull(groups = MyGroup.class) String arg1, @Max(10) int arg2);
+		@MyValid
+		@Async void myValidAsyncMethod(@NotNull(groups = OtherGroup.class) String arg1, @Max(10) int arg2);
 	}
 
 
@@ -132,9 +133,19 @@ public class MethodValidationTests {
 	}
 
 
+	public interface OtherGroup {
+	}
+
+
 	@Validated({MyGroup.class, Default.class})
 	@Retention(RetentionPolicy.RUNTIME)
 	public @interface MyStereotype {
 	}
 
+
+	@Validated({OtherGroup.class, Default.class})
+	@Retention(RetentionPolicy.RUNTIME)
+	public @interface MyValid {
+	}
+
 }