Allow Errors after @RequestBody and @RequestPart

An @RequestBody or an @RequestPart argument can now be followed by an
Errors/BindingResult argument making it possible to handle validation
errors (as a result of an @Valid annotation) locally within the
@RequestMapping method.

Issue: SPR-7114

spring-web/src/main/java/org/springframework/web/bind/annotation/RequestMapping.java

@@ -100,9 +100,8 @@ import java.util.concurrent.Callable;
  * converted to the declared method argument type using
  * {@linkplain org.springframework.http.converter.HttpMessageConverter message
  * converters}. Such parameters may optionally be annotated with {@code @Valid}
- * but do not support access to validation results through a
- * {@link org.springframework.validation.Errors} /
- * {@link org.springframework.validation.BindingResult} argument.
+ * and also support access to validation results through an
+ * {@link org.springframework.validation.Errors} argument.
  * Instead a {@link org.springframework.web.servlet.mvc.method.annotation.MethodArgumentNotValidException}
  * exception is raised.
  * <li>{@link RequestPart @RequestPart} annotated parameters
@@ -112,9 +111,8 @@ import java.util.concurrent.Callable;
  * converted to the declared method argument type using
  * {@linkplain org.springframework.http.converter.HttpMessageConverter message
  * converters}. Such parameters may optionally be annotated with {@code @Valid}
- * but do not support access to validation results through a
- * {@link org.springframework.validation.Errors} /
- * {@link org.springframework.validation.BindingResult} argument.
+ * and support access to validation results through a
+ * {@link org.springframework.validation.Errors} argument.
  * Instead a {@link org.springframework.web.servlet.mvc.method.annotation.MethodArgumentNotValidException}
  * exception is raised.
  * <li>{@link org.springframework.http.HttpEntity HttpEntity&lt;?&gt;} parameters

spring-web/src/main/java/org/springframework/web/method/annotation/ErrorsMethodArgumentResolver.java

@@ -60,8 +60,8 @@ public class ErrorsMethodArgumentResolver implements HandlerMethodArgumentResolv
 		}
 
 		throw new IllegalStateException(
-				"An Errors/BindingResult argument is expected to be immediately after the model attribute " +
-				"argument in the controller method signature: " + parameter.getMethod());
+				"An Errors/BindingResult argument is expected to be declared immediately after the model attribute, " +
+				"the @RequestBody or the @RequestPart arguments to which they apply: " + parameter.getMethod());
 	}
 
 }

spring-web/src/main/java/org/springframework/web/method/annotation/ModelAttributeMethodProcessor.java

@@ -157,16 +157,16 @@ public class ModelAttributeMethodProcessor implements HandlerMethodArgumentResol
 			if (annot.annotationType().getSimpleName().startsWith("Valid")) {
 				Object hints = AnnotationUtils.getValue(annot);
 				binder.validate(hints instanceof Object[] ? (Object[]) hints : new Object[] {hints});
+				break;
 			}
 		}
 	}
 
 	/**
-	 * Whether to raise a {@link BindException} on bind or validation errors.
-	 * The default implementation returns {@code true} if the next method
-	 * argument is not of type {@link Errors}.
+	 * Whether to raise a {@link BindException} on validation errors.
 	 * @param binder the data binder used to perform data binding
 	 * @param parameter the method argument
+	 * @return {@code true} if the next method argument is not of type {@link Errors}.
 	 */
 	protected boolean isBindExceptionRequired(WebDataBinder binder, MethodParameter parameter) {
 		int i = parameter.getParameterIndex();