Avoid defensive check for Servlet 3.1 Part interface

Issue: SPR-14467

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

@@ -39,6 +39,7 @@ import org.springframework.web.method.support.ModelAndViewContainer;
  * Abstract base class for resolving method arguments from a named value.
  * Request parameters, request headers, and path variables are examples of named
  * values. Each may have a name, a required flag, and a default value.
+ *
  * <p>Subclasses define how to do the following:
  * <ul>
  * <li>Obtain named value information for a method parameter
@@ -46,9 +47,11 @@ import org.springframework.web.method.support.ModelAndViewContainer;
  * <li>Handle missing argument values when argument values are required
  * <li>Optionally handle a resolved value
  * </ul>
+ *
  * <p>A default value string can contain ${...} placeholders and Spring Expression
  * Language #{...} expressions. For this to work a
  * {@link ConfigurableBeanFactory} must be supplied to the class constructor.
+ *
  * <p>A {@link WebDataBinder} is created to apply type conversion to the resolved
  * argument value if it doesn't match the method parameter type.
  *
@@ -78,7 +81,8 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 	 */
 	public AbstractNamedValueMethodArgumentResolver(ConfigurableBeanFactory beanFactory) {
 		this.configurableBeanFactory = beanFactory;
-		this.expressionContext = (beanFactory != null ? new BeanExpressionContext(beanFactory, new RequestScope()) : null);
+		this.expressionContext =
+				(beanFactory != null ? new BeanExpressionContext(beanFactory, new RequestScope()) : null);
 	}
 
 
@@ -204,7 +208,9 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 	 * @param request the current request
 	 * @since 4.3
 	 */
-	protected void handleMissingValue(String name, MethodParameter parameter, NativeWebRequest request) throws Exception {
+	protected void handleMissingValue(String name, MethodParameter parameter, NativeWebRequest request)
+			throws Exception {
+
 		handleMissingValue(name, parameter);
 	}
 
@@ -241,7 +247,7 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 	 * @param arg the resolved argument value
 	 * @param name the argument name
 	 * @param parameter the argument parameter type
-	 * @param mavContainer the {@link ModelAndViewContainer}, which may be {@code null}
+	 * @param mavContainer the {@link ModelAndViewContainer} (may be {@code null})
 	 * @param webRequest the current request
 	 */
 	protected void handleResolvedValue(Object arg, String name, MethodParameter parameter,

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

@@ -21,6 +21,7 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.Part;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
@@ -181,7 +182,9 @@ public class RequestParamMethodArgumentResolver extends AbstractNamedValueMethod
 	}
 
 	@Override
-	protected void handleMissingValue(String name, MethodParameter parameter, NativeWebRequest request) throws Exception {
+	protected void handleMissingValue(String name, MethodParameter parameter, NativeWebRequest request)
+			throws Exception {
+
 		HttpServletRequest servletRequest = request.getNativeRequest(HttpServletRequest.class);
 		if (MultipartResolutionDelegate.isMultipartArgument(parameter)) {
 			if (!MultipartResolutionDelegate.isMultipartRequest(servletRequest)) {
@@ -192,7 +195,8 @@ public class RequestParamMethodArgumentResolver extends AbstractNamedValueMethod
 			}
 		}
 		else {
-			throw new MissingServletRequestParameterException(name, parameter.getNestedParameterType().getSimpleName());
+			throw new MissingServletRequestParameterException(name,
+					parameter.getNestedParameterType().getSimpleName());
 		}
 	}
 
@@ -201,8 +205,7 @@ public class RequestParamMethodArgumentResolver extends AbstractNamedValueMethod
 			UriComponentsBuilder builder, Map<String, Object> uriVariables, ConversionService conversionService) {
 
 		Class<?> paramType = parameter.getNestedParameterType();
-		if (Map.class.isAssignableFrom(paramType) || MultipartFile.class == paramType ||
-				"javax.servlet.http.Part".equals(paramType.getName())) {
+		if (Map.class.isAssignableFrom(paramType) || MultipartFile.class == paramType || Part.class == paramType) {
 			return;
 		}