Unwrap SpringValidatorAdapter (e.g. CustomValidatorBean) to native Validator

Issue: SPR-15629

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

@@ -85,9 +85,13 @@ public class MethodValidationPostProcessor extends AbstractBeanFactoryAwareAdvis
 	 * <p>Default is the default ValidatorFactory's default Validator.
 	 */
 	public void setValidator(Validator validator) {
+		// Unwrap to the native Validator with forExecutables support
 		if (validator instanceof LocalValidatorFactoryBean) {
 			this.validator = ((LocalValidatorFactoryBean) validator).getValidator();
 		}
+		else if (validator instanceof SpringValidatorAdapter) {
+			this.validator = validator.unwrap(Validator.class);
+		}
 		else {
 			this.validator = validator;
 		}

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

@@ -25,6 +25,8 @@ import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
 import javax.validation.ConstraintViolation;
+import javax.validation.ValidationException;
+import javax.validation.Validator;
 import javax.validation.metadata.BeanDescriptor;
 import javax.validation.metadata.ConstraintDescriptor;
 
@@ -39,13 +41,19 @@ import org.springframework.validation.ObjectError;
 import org.springframework.validation.SmartValidator;
 
 /**
- * Adapter that takes a JSR-303 {@code javax.validator.Validator}
+ * Adapter that takes a JSR-303 {@code javax.validator.Validator} and
- * and exposes it as a Spring {@link org.springframework.validation.Validator}
+ * exposes it as a Spring {@link org.springframework.validation.Validator}
  * while also exposing the original JSR-303 Validator interface itself.
  *
  * <p>Can be used as a programmatic wrapper. Also serves as base class for
  * {@link CustomValidatorBean} and {@link LocalValidatorFactoryBean}.
  *
+ * <p>Note that Bean Validation 1.1's {@code #forExecutables} method isn't supported
+ * on this adapter: We do not expect that method to be called by application code;
+ * consider {@link MethodValidationInterceptor} instead. If you really need programmatic
+ * {@code #forExecutables} access, call {@code #unwrap(Validator.class) which will
+ * provide the native {@link Validator} object with {@code #forExecutables} support.
+ *
  * @author Juergen Hoeller
  * @since 3.0
  */
@@ -297,7 +305,16 @@ public class SpringValidatorAdapter implements SmartValidator, javax.validation.
 	@SuppressWarnings("unchecked")
 	public <T> T unwrap(Class<T> type) {
 		Assert.state(this.targetValidator != null, "No target Validator set");
-		return (type != null ? this.targetValidator.unwrap(type) : (T) this.targetValidator);
+		try {
+			return (type != null ? this.targetValidator.unwrap(type) : (T) this.targetValidator);
+		}
+		catch (ValidationException ex) {
+			// ignore if just being asked for plain Validator
+			if (Validator.class == type) {
+				return (T) this.targetValidator;
+			}
+			throw ex;
+		}
 	}