added SmartValidator interface with general support for validation hints; added custom @Valid annotation with support for JSR-303 validation groups; JSR-303 SpringValidatorAdapter and MVC data binding provide support for validation groups (SPR-6373)

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

@@ -706,8 +706,22 @@ public class DataBinder implements PropertyEditorRegistry, TypeConverter {
 	 * @see #getBindingResult()
 	 */
 	public void validate() {
+		this.validator.validate(getTarget(), getBindingResult());
+	}
+
+	/**
+	 * Invoke the specified Validator, if any, with the given validation hints.
+	 * <p>Note: Validation hints may get ignored by the actual target Validator.
+	 * @param validationHints one or more hint objects to be passed to a {@link SmartValidator}
+	 * @see #setValidator(Validator)
+	 * @see SmartValidator#validate(Object, Errors, Object...)
+	 */
+	public void validate(Object... validationHints) {
 		Validator validator = getValidator();
-		if (validator != null) {
+		if (validator instanceof SmartValidator) {
+			((SmartValidator) validator).validate(getTarget(), getBindingResult(), validationHints);
+		}
+		else if (validator != null) {
 			validator.validate(getTarget(), getBindingResult());
 		}
 	}

org.springframework.context/src/main/java/org/springframework/validation/SmartValidator.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2002-2011 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.validation;
+
+/**
+ * Extended variant of the {@link Validator} interface, adding support for
+ * validation 'hints'.
+ *
+ * @author Juergen Hoeller
+ * @since 3.1
+ */
+public interface SmartValidator extends Validator {
+
+	/**
+	 * Validate the supplied <code>target</code> object, which must be
+	 * of a {@link Class} for which the {@link #supports(Class)} method
+	 * typically has (or would) return <code>true</code>.
+	 * <p>The supplied {@link Errors errors} instance can be used to report
+	 * any resulting validation errors.
+	 * <p><b>This variant of <code>validate</code> supports validation hints,
+	 * such as validation groups against a JSR-303 provider</b> (in this case,
+	 * the provided hint objects need to be annotation arguments of type Class).
+	 * <p>Note: Validation hints may get ignored by the actual target Validator,
+	 * in which case this method is supposed to be behave just like its regular
+	 * {@link #validate(Object, Errors)} sibling.
+	 * @param target the object that is to be validated (can be <code>null</code>)
+	 * @param errors contextual state about the validation process (never <code>null</code>)
+	 * @param validationHints one or more hint objects to be passed to the validation engine
+	 * @see ValidationUtils
+	 */
+	void validate(Object target, Errors errors, Object... validationHints);
+
+}

org.springframework.context/src/main/java/org/springframework/validation/annotation/Valid.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2002-2011 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.validation.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Extended variant of JSR-303's {@link javax.validation.Valid},
+ * supporting the specification of validation groups. Designed for
+ * convenient use with Spring's JSR-303 support but not JSR-303 specific.
+ *
+ * <p>Can be used e.g. with Spring MVC handler methods arguments.
+ * Supported through {@link org.springframework.validation.SmartValidator}'s
+ * validation hint concept, with validation group classes acting as hint objects.
+ *
+ * @author Juergen Hoeller
+ * @since 3.1
+ * @see javax.validation.Validator#validate(Object, Class[])
+ * @see org.springframework.validation.SmartValidator#validate(Object, org.springframework.validation.Errors, Object...)
+ * @see org.springframework.validation.beanvalidation.SpringValidatorAdapter
+ */
+@Target(ElementType.PARAMETER)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface Valid {
+
+	/**
+	 * Specify one or more validation groups to apply to the validation step
+	 * kicked off by this annotation.
+	 * <p>JSR-303 defines validation groups as custom annotations which an application declares
+	 * for the sole purpose of using them as type-safe group arguments, as implemented in
+	 * {@link org.springframework.validation.beanvalidation.SpringValidatorAdapter}.
+	 * <p>Other {@link org.springframework.validation.SmartValidator} implementations may
+	 * support class arguments in other ways as well.
+	 */
+	Class[] value() default {};
+
+}

org.springframework.context/src/main/java/org/springframework/validation/annotation/package-info.java

@@ -0,0 +1,8 @@
+/**
+ * Support classes for annotation-based constraint evaluation,
+ * e.g. using a JSR-303 Bean Validation provider.
+ *
+ * <p>Provides an extended variant of JSR-303's <code>@Valid</code>,
+ * supporting the specification of validation groups.
+ */
+package org.springframework.validation.annotation;

org.springframework.context/src/main/java/org/springframework/validation/beanvalidation/SpringValidatorAdapter.java

@@ -17,6 +17,7 @@
 package org.springframework.validation.beanvalidation;
 
 import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -33,7 +34,7 @@ import org.springframework.validation.BindingResult;
 import org.springframework.validation.Errors;
 import org.springframework.validation.FieldError;
 import org.springframework.validation.ObjectError;
-import org.springframework.validation.Validator;
+import org.springframework.validation.SmartValidator;
 
 /**
  * Adapter that takes a JSR-303 <code>javax.validator.Validator</code>
@@ -46,7 +47,7 @@ import org.springframework.validation.Validator;
  * @author Juergen Hoeller
  * @since 3.0
  */
-public class SpringValidatorAdapter implements Validator, javax.validation.Validator {
+public class SpringValidatorAdapter implements SmartValidator, javax.validation.Validator {
 
 	private static final Set<String> internalAnnotationAttributes = new HashSet<String>(3);
 
@@ -85,8 +86,29 @@ public class SpringValidatorAdapter implements Validator, javax.validation.Valid
 	}
 
 	public void validate(Object target, Errors errors) {
-		Set<ConstraintViolation<Object>> result = this.targetValidator.validate(target);
-		for (ConstraintViolation<Object> violation : result) {
+		processConstraintViolations(this.targetValidator.validate(target), errors);
+	}
+
+	public void validate(Object target, Errors errors, Object[] validationHints) {
+		Set<Class> groups = new LinkedHashSet<Class>();
+		if (validationHints != null) {
+			for (Object hint : validationHints) {
+				if (hint instanceof Class) {
+					groups.add((Class) hint);
+				}
+			}
+		}
+		processConstraintViolations(this.targetValidator.validate(target, groups.toArray(new Class[groups.size()])), errors);
+	}
+
+	/**
+	 * Process the given JSR-303 ConstraintViolations, adding corresponding errors to
+	 * the provided Spring {@link Errors} object.
+	 * @param violations the JSR-303 ConstraintViolation results
+	 * @param errors the Spring errors object to register to
+	 */
+	protected void processConstraintViolations(Set<ConstraintViolation<Object>> violations, Errors errors) {
+		for (ConstraintViolation<Object> violation : violations) {
 			String field = violation.getPropertyPath().toString();
 			FieldError fieldError = errors.getFieldError(field);
 			if (fieldError == null || !fieldError.isBindingFailure()) {