@RequestPart supports java.util.Optional

Issue: SPR-12644

spring-core/src/main/java/org/springframework/core/MethodParameter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -309,6 +309,7 @@ public class MethodParameter {
 	/**
 	 * Return the generic type of the method/constructor parameter.
 	 * @return the parameter type (never {@code null})
+	 * @since 3.0
 	 */
 	public Type getGenericParameterType() {
 		if (this.genericParameterType == null) {
@@ -324,6 +325,12 @@ public class MethodParameter {
 		return this.genericParameterType;
 	}
 
+	/**
+	 * Return the nested type of the method/constructor parameter.
+	 * @return the parameter type (never {@code null})
+	 * @see #getNestingLevel()
+	 * @since 3.1
+	 */
 	public Class<?> getNestedParameterType() {
 		if (this.nestingLevel > 1) {
 			Type type = getGenericParameterType();
@@ -350,6 +357,29 @@ public class MethodParameter {
 		}
 	}
 
+	/**
+	 * Return the nested generic type of the method/constructor parameter.
+	 * @return the parameter type (never {@code null})
+	 * @see #getNestingLevel()
+	 * @since 4.2
+	 */
+	public Type getNestedGenericParameterType() {
+		if (this.nestingLevel > 1) {
+			Type type = getGenericParameterType();
+			for (int i = 2; i <= this.nestingLevel; i++) {
+				if (type instanceof ParameterizedType) {
+					Type[] args = ((ParameterizedType) type).getActualTypeArguments();
+					Integer index = getTypeIndexForLevel(i);
+					type = args[index != null ? index : args.length - 1];
+				}
+			}
+			return type;
+		}
+		else {
+			return getGenericParameterType();
+		}
+	}
+
 	/**
 	 * Return the annotations associated with the target method/constructor itself.
 	 */

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/AbstractMessageConverterMethodArgumentResolver.java

@@ -104,7 +104,7 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 	 * from the given HttpInputMessage.
 	 * @param <T> the expected type of the argument value to be created
 	 * @param inputMessage the HTTP input message representing the current request
-	 * @param methodParam the method argument
+	 * @param methodParam the method parameter descriptor (may be {@code null})
 	 * @param targetType the type of object to create, not necessarily the same as
 	 * the method parameter type (e.g. for {@code HttpEntity<String>} method
 	 * parameter the target type is String)
@@ -113,8 +113,8 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 	 * @throws HttpMediaTypeNotSupportedException if no suitable message converter is found
 	 */
 	@SuppressWarnings("unchecked")
-	protected <T> Object readWithMessageConverters(HttpInputMessage inputMessage,
-			MethodParameter methodParam, Type targetType) throws IOException, HttpMediaTypeNotSupportedException {
+	protected <T> Object readWithMessageConverters(HttpInputMessage inputMessage, MethodParameter methodParam,
+			Type targetType) throws IOException, HttpMediaTypeNotSupportedException {
 
 		MediaType contentType;
 		try {
@@ -127,7 +127,13 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 			contentType = MediaType.APPLICATION_OCTET_STREAM;
 		}
 
-		Class<?> contextClass = methodParam.getContainingClass();
+		Class<?> contextClass = (methodParam != null ? methodParam.getContainingClass() : null);
+		Class<T> targetClass = (targetType instanceof Class<?> ? (Class<T>) targetType : null);
+		if (targetClass == null) {
+			ResolvableType resolvableType = (methodParam != null ?
+					ResolvableType.forMethodParameter(methodParam) : ResolvableType.forType(targetType));
+			targetClass = (Class<T>) resolvableType.resolve();
+		}
 
 		for (HttpMessageConverter<?> converter : this.messageConverters) {
 			if (converter instanceof GenericHttpMessageConverter) {
@@ -140,14 +146,14 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 					return genericConverter.read(targetType, contextClass, inputMessage);
 				}
 			}
-			Class<T> targetClass = (Class<T>)
-					ResolvableType.forMethodParameter(methodParam, targetType).resolve(Object.class);
-			if (converter.canRead(targetClass, contentType)) {
-				if (logger.isDebugEnabled()) {
-					logger.debug("Reading [" + targetClass.getName() + "] as \"" +
-							contentType + "\" using [" + converter + "]");
+			else if (targetClass != null) {
+				if (converter.canRead(targetClass, contentType)) {
+					if (logger.isDebugEnabled()) {
+						logger.debug("Reading [" + targetClass.getName() + "] as \"" +
+								contentType + "\" using [" + converter + "]");
+					}
+					return ((HttpMessageConverter<T>) converter).read(targetClass, inputMessage);
 				}
-				return ((HttpMessageConverter<T>) converter).read(targetClass, inputMessage);
 			}
 		}
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestPartMethodArgumentResolver.java

@@ -20,6 +20,7 @@ import java.lang.annotation.Annotation;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Optional;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.Part;
 
@@ -80,12 +81,13 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 		super(messageConverters);
 	}
 
+
 	/**
 	 * Supports the following:
 	 * <ul>
-	 * 	<li>Annotated with {@code @RequestPart}
-	 * 	<li>Of type {@link MultipartFile} unless annotated with {@code @RequestParam}.
-	 * 	<li>Of type {@code javax.servlet.http.Part} unless annotated with {@code @RequestParam}.
+	 * <li>Annotated with {@code @RequestPart}
+	 * <li>Of type {@link MultipartFile} unless annotated with {@code @RequestParam}.
+	 * <li>Of type {@code javax.servlet.http.Part} unless annotated with {@code @RequestParam}.
 	 * </ul>
 	 */
 	@Override
@@ -117,12 +119,19 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 		assertIsMultipartRequest(servletRequest);
 
 		MultipartHttpServletRequest multipartRequest =
-			WebUtils.getNativeRequest(servletRequest, MultipartHttpServletRequest.class);
+				WebUtils.getNativeRequest(servletRequest, MultipartHttpServletRequest.class);
+
+		Class<?> paramType = parameter.getParameterType();
+		boolean optional = paramType.getName().equals("java.util.Optional");
+		if (optional) {
+			parameter.increaseNestingLevel();
+			paramType = parameter.getNestedParameterType();
+		}
 
 		String partName = getPartName(parameter);
 		Object arg;
 
-		if (MultipartFile.class.equals(parameter.getParameterType())) {
+		if (MultipartFile.class.equals(paramType)) {
 			Assert.notNull(multipartRequest, "Expected MultipartHttpServletRequest: is a MultipartResolver configured?");
 			arg = multipartRequest.getFile(partName);
 		}
@@ -135,7 +144,7 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 			List<MultipartFile> files = multipartRequest.getFiles(partName);
 			arg = files.toArray(new MultipartFile[files.size()]);
 		}
-		else if ("javax.servlet.http.Part".equals(parameter.getParameterType().getName())) {
+		else if ("javax.servlet.http.Part".equals(paramType.getName())) {
 			assertIsMultipartRequest(servletRequest);
 			arg = servletRequest.getPart(partName);
 		}
@@ -150,7 +159,7 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 		else {
 			try {
 				HttpInputMessage inputMessage = new RequestPartServletServerHttpRequest(servletRequest, partName);
-				arg = readWithMessageConverters(inputMessage, parameter, parameter.getParameterType());
+				arg = readWithMessageConverters(inputMessage, parameter, parameter.getNestedGenericParameterType());
 				WebDataBinder binder = binderFactory.createBinder(request, arg, partName);
 				if (arg != null) {
 					validate(binder, parameter);
@@ -164,11 +173,14 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 		}
 
 		RequestPart annot = parameter.getParameterAnnotation(RequestPart.class);
-		boolean isRequired = (annot == null || annot.required());
+		boolean isRequired = ((annot == null || annot.required()) && !optional);
 
 		if (arg == null && isRequired) {
 			throw new MissingServletRequestPartException(partName);
 		}
+		if (optional) {
+			arg = Optional.ofNullable(arg);
+		}
 
 		return arg;
 	}
@@ -180,41 +192,44 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 		}
 	}
 
-	private String getPartName(MethodParameter parameter) {
-		RequestPart annot = parameter.getParameterAnnotation(RequestPart.class);
+	private String getPartName(MethodParameter param) {
+		RequestPart annot = param.getParameterAnnotation(RequestPart.class);
 		String partName = (annot != null ? annot.value() : "");
 		if (partName.length() == 0) {
-			partName = parameter.getParameterName();
-			Assert.notNull(partName, "Request part name for argument type [" + parameter.getParameterType().getName() +
-					"] not specified, and parameter name information not found in class file either.");
+			partName = param.getParameterName();
+			if (partName == null) {
+				throw new IllegalArgumentException("Request part name for argument type [" +
+						param.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
+			}
 		}
 		return partName;
 	}
 
-	private boolean isMultipartFileCollection(MethodParameter parameter) {
-		Class<?> collectionType = getCollectionParameterType(parameter);
+	private boolean isMultipartFileCollection(MethodParameter param) {
+		Class<?> collectionType = getCollectionParameterType(param);
 		return (collectionType != null && collectionType.equals(MultipartFile.class));
 	}
 
-	private boolean isMultipartFileArray(MethodParameter parameter) {
-		Class<?> paramType = parameter.getParameterType().getComponentType();
+	private boolean isMultipartFileArray(MethodParameter param) {
+		Class<?> paramType = param.getNestedParameterType().getComponentType();
 		return (paramType != null && MultipartFile.class.equals(paramType));
 	}
 
-	private boolean isPartCollection(MethodParameter parameter) {
-		Class<?> collectionType = getCollectionParameterType(parameter);
+	private boolean isPartCollection(MethodParameter param) {
+		Class<?> collectionType = getCollectionParameterType(param);
 		return (collectionType != null && "javax.servlet.http.Part".equals(collectionType.getName()));
 	}
 
-	private boolean isPartArray(MethodParameter parameter) {
-		Class<?> paramType = parameter.getParameterType().getComponentType();
+	private boolean isPartArray(MethodParameter param) {
+		Class<?> paramType = param.getNestedParameterType().getComponentType();
 		return (paramType != null && "javax.servlet.http.Part".equals(paramType.getName()));
 	}
 
-	private Class<?> getCollectionParameterType(MethodParameter parameter) {
-		Class<?> paramType = parameter.getParameterType();
+	private Class<?> getCollectionParameterType(MethodParameter param) {
+		Class<?> paramType = param.getNestedParameterType();
 		if (Collection.class.equals(paramType) || List.class.isAssignableFrom(paramType)){
-			Class<?> valueType = GenericCollectionTypeResolver.getCollectionParameterType(parameter);
+			Class<?> valueType = GenericCollectionTypeResolver.getCollectionParameterType(param);
 			if (valueType != null) {
 				return valueType;
 			}
@@ -228,13 +243,13 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 	 * Spring's {@link org.springframework.validation.annotation.Validated},
 	 * and custom annotations whose name starts with "Valid".
 	 * @param binder the DataBinder to be used
-	 * @param parameter the method parameter
+	 * @param param the method parameter
 	 * @throws MethodArgumentNotValidException in case of a binding error which
 	 * is meant to be fatal (i.e. without a declared {@link Errors} parameter)
 	 * @see #isBindingErrorFatal
 	 */
-	protected void validate(WebDataBinder binder, MethodParameter parameter) throws MethodArgumentNotValidException {
-		Annotation[] annotations = parameter.getParameterAnnotations();
+	protected void validate(WebDataBinder binder, MethodParameter param) throws MethodArgumentNotValidException {
+		Annotation[] annotations = param.getParameterAnnotations();
 		for (Annotation ann : annotations) {
 			Validated validatedAnn = AnnotationUtils.getAnnotation(ann, Validated.class);
 			if (validatedAnn != null || ann.annotationType().getSimpleName().startsWith("Valid")) {
@@ -243,8 +258,8 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 				binder.validate(validationHints);
 				BindingResult bindingResult = binder.getBindingResult();
 				if (bindingResult.hasErrors()) {
-					if (isBindingErrorFatal(parameter)) {
-						throw new MethodArgumentNotValidException(parameter, bindingResult);
+					if (isBindingErrorFatal(param)) {
+						throw new MethodArgumentNotValidException(param, bindingResult);
 					}
 				}
 			}

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestPartMethodArgumentResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -16,11 +16,11 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
-import java.io.IOException;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import javax.servlet.http.Part;
 import javax.validation.Valid;
 import javax.validation.constraints.NotNull;
@@ -82,6 +82,9 @@ public class RequestPartMethodArgumentResolverTests {
 	private MethodParameter paramPartList;
 	private MethodParameter paramPartArray;
 	private MethodParameter paramRequestParamAnnot;
+	private MethodParameter optionalMultipartFile;
+	private MethodParameter optionalPart;
+	private MethodParameter optionalRequestPart;
 
 	private NativeWebRequest webRequest;
 
@@ -89,14 +92,14 @@ public class RequestPartMethodArgumentResolverTests {
 
 	private MockHttpServletResponse servletResponse;
 
+
 	@SuppressWarnings("unchecked")
 	@Before
 	public void setUp() throws Exception {
-
 		Method method = getClass().getMethod("handle", SimpleBean.class, SimpleBean.class,
 				SimpleBean.class, MultipartFile.class, List.class, MultipartFile[].class,
-				Integer.TYPE, MultipartFile.class, Part.class, List.class,
-				Part[].class, MultipartFile.class);
+				Integer.TYPE, MultipartFile.class, Part.class, List.class, Part[].class,
+				MultipartFile.class, Optional.class, Optional.class, Optional.class);
 
 		paramRequestPart = new MethodParameter(method, 0);
 		paramRequestPart.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
@@ -113,6 +116,11 @@ public class RequestPartMethodArgumentResolverTests {
 		paramPartList = new MethodParameter(method, 9);
 		paramPartArray = new MethodParameter(method, 10);
 		paramRequestParamAnnot = new MethodParameter(method, 11);
+		optionalMultipartFile = new MethodParameter(method, 12);
+		optionalMultipartFile.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
+		optionalPart = new MethodParameter(method, 13);
+		optionalPart.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
+		optionalRequestPart = new MethodParameter(method, 14);
 
 		messageConverter = mock(HttpMessageConverter.class);
 		given(messageConverter.getSupportedMediaTypes()).willReturn(Collections.singletonList(MediaType.TEXT_PLAIN));
@@ -129,6 +137,7 @@ public class RequestPartMethodArgumentResolverTests {
 		webRequest = new ServletWebRequest(multipartRequest, servletResponse);
 	}
 
+
 	@Test
 	public void supportsParameter() {
 		assertTrue("RequestPart parameter not supported", resolver.supportsParameter(paramRequestPart));
@@ -139,8 +148,8 @@ public class RequestPartMethodArgumentResolverTests {
 		assertTrue("MultipartFile parameter not supported", resolver.supportsParameter(paramMultipartFile));
 		assertTrue("List<MultipartFile> parameter not supported", resolver.supportsParameter(paramMultipartFileList));
 		assertTrue("MultipartFile[] parameter not supported", resolver.supportsParameter(paramMultipartFileArray));
-		assertFalse("non-RequestPart parameter supported", resolver.supportsParameter(paramInt));
-		assertFalse("@RequestParam args not supported", resolver.supportsParameter(paramRequestParamAnnot));
+		assertFalse("non-RequestPart parameter should not be supported", resolver.supportsParameter(paramInt));
+		assertFalse("@RequestParam args should not be supported", resolver.supportsParameter(paramRequestParamAnnot));
 	}
 
 	@Test
@@ -243,21 +252,27 @@ public class RequestPartMethodArgumentResolverTests {
 		testResolveArgument(new SimpleBean("foo"), paramNamedRequestPart);
 	}
 
+	@Test
+	public void resolveNamedRequestPartNotPresent() throws Exception {
+		testResolveArgument(null, paramNamedRequestPart);
+	}
+
 	@Test
 	public void resolveRequestPartNotValid() throws Exception {
 		try {
 			testResolveArgument(new SimpleBean(null), paramValidRequestPart);
 			fail("Expected exception");
-		} catch (MethodArgumentNotValidException e) {
-			assertEquals("requestPart", e.getBindingResult().getObjectName());
-			assertEquals(1, e.getBindingResult().getErrorCount());
-			assertNotNull(e.getBindingResult().getFieldError("name"));
+		}
+		catch (MethodArgumentNotValidException ex) {
+			assertEquals("requestPart", ex.getBindingResult().getObjectName());
+			assertEquals(1, ex.getBindingResult().getErrorCount());
+			assertNotNull(ex.getBindingResult().getFieldError("name"));
 		}
 	}
 
 	@Test
 	public void resolveRequestPartValid() throws Exception {
-		testResolveArgument(new SimpleBean("foo"), paramNamedRequestPart);
+		testResolveArgument(new SimpleBean("foo"), paramValidRequestPart);
 	}
 
 	@Test
@@ -265,8 +280,9 @@ public class RequestPartMethodArgumentResolverTests {
 		try {
 			testResolveArgument(null, paramValidRequestPart);
 			fail("Expected exception");
-		} catch (MissingServletRequestPartException e) {
-			assertEquals("requestPart", e.getRequestPartName());
+		}
+		catch (MissingServletRequestPartException ex) {
+			assertEquals("requestPart", ex.getRequestPartName());
 		}
 	}
 
@@ -275,27 +291,100 @@ public class RequestPartMethodArgumentResolverTests {
 		testResolveArgument(new SimpleBean("foo"), paramValidRequestPart);
 	}
 
-	@Test(expected=MultipartException.class)
+	@Test(expected = MultipartException.class)
 	public void isMultipartRequest() throws Exception {
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		resolver.resolveArgument(paramMultipartFile, new ModelAndViewContainer(), new ServletWebRequest(request), null);
-		fail("Expected exception");
 	}
 
-	// SPR-9079
-
-	@Test
+	@Test  // SPR-9079
 	public void isMultipartRequestPut() throws Exception {
 		this.multipartRequest.setMethod("PUT");
 		Object actual = resolver.resolveArgument(paramMultipartFile, null, webRequest, null);
-		assertNotNull(actual);
 		assertSame(multipartFile1, actual);
 	}
 
-	private void testResolveArgument(SimpleBean argValue, MethodParameter parameter) throws IOException, Exception {
-		MediaType contentType = MediaType.TEXT_PLAIN;
+	@Test
+	public void resolveOptionalMultipartFileArgument() throws Exception {
+		MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
+		MultipartFile expected = new MockMultipartFile("optionalMultipartFile", "Hello World".getBytes());
+		request.addFile(expected);
+		webRequest = new ServletWebRequest(request);
+
+		Object result = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+
+		assertTrue(result instanceof Optional);
+		assertEquals("Invalid result", expected, ((Optional) result).get());
+	}
+
+	@Test
+	public void resolveOptionalMultipartFileArgumentNotPresent() throws Exception {
+		MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
+		webRequest = new ServletWebRequest(request);
+
+		Object result = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+
+		assertTrue(result instanceof Optional);
+		assertFalse("Invalid result", ((Optional) result).isPresent());
+	}
+
+	@Test
+	public void resolveOptionalPartArgument() throws Exception {
+		MockPart expected = new MockPart("optionalPart", "Hello World".getBytes());
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("POST");
+		request.setContentType("multipart/form-data");
+		request.addPart(expected);
+		webRequest = new ServletWebRequest(request);
+
+		Object result = resolver.resolveArgument(optionalPart, null, webRequest, null);
+
+		assertTrue(result instanceof Optional);
+		assertEquals("Invalid result", expected, ((Optional) result).get());
+	}
+
+	@Test
+	public void resolveOptionalPartArgumentNotPresent() throws Exception {
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("POST");
+		request.setContentType("multipart/form-data");
+		webRequest = new ServletWebRequest(request);
+
+		Object result = resolver.resolveArgument(optionalPart, null, webRequest, null);
+
+		assertTrue(result instanceof Optional);
+		assertFalse("Invalid result", ((Optional) result).isPresent());
+	}
 
-		given(messageConverter.canRead(SimpleBean.class, contentType)).willReturn(true);
+	@Test
+	public void resolveOptionalRequestPart() throws Exception {
+		SimpleBean simpleBean = new SimpleBean("foo");
+
+		given(messageConverter.canRead(SimpleBean.class, MediaType.TEXT_PLAIN)).willReturn(true);
+		given(messageConverter.read(eq(SimpleBean.class), isA(RequestPartServletServerHttpRequest.class))).willReturn(simpleBean);
+
+		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
+		Object actualValue = resolver.resolveArgument(optionalRequestPart, mavContainer, webRequest, new ValidatingBinderFactory());
+
+		assertEquals("Invalid argument value", Optional.of(simpleBean), actualValue);
+		assertFalse("The requestHandled flag shouldn't change", mavContainer.isRequestHandled());
+	}
+
+	@Test
+	public void resolveOptionalRequestPartNotPresent() throws Exception {
+		given(messageConverter.canRead(SimpleBean.class, MediaType.TEXT_PLAIN)).willReturn(true);
+		given(messageConverter.read(eq(SimpleBean.class), isA(RequestPartServletServerHttpRequest.class))).willReturn(null);
+
+		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
+		Object actualValue = resolver.resolveArgument(optionalRequestPart, mavContainer, webRequest, new ValidatingBinderFactory());
+
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+		assertFalse("The requestHandled flag shouldn't change", mavContainer.isRequestHandled());
+	}
+
+
+	private void testResolveArgument(SimpleBean argValue, MethodParameter parameter) throws Exception {
+		given(messageConverter.canRead(SimpleBean.class, MediaType.TEXT_PLAIN)).willReturn(true);
 		given(messageConverter.read(eq(SimpleBean.class), isA(RequestPartServletServerHttpRequest.class))).willReturn(argValue);
 
 		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
@@ -305,6 +394,7 @@ public class RequestPartMethodArgumentResolverTests {
 		assertFalse("The requestHandled flag shouldn't change", mavContainer.isRequestHandled());
 	}
 
+
 	private static class SimpleBean {
 
 		@NotNull
@@ -320,7 +410,9 @@ public class RequestPartMethodArgumentResolverTests {
 		}
 	}
 
+
 	private final class ValidatingBinderFactory implements WebDataBinderFactory {
+
 		@Override
 		public WebDataBinder createBinder(NativeWebRequest webRequest, Object target, String objectName) throws Exception {
 			LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
@@ -331,6 +423,7 @@ public class RequestPartMethodArgumentResolverTests {
 		}
 	}
 
+
 	public void handle(@RequestPart SimpleBean requestPart,
 					   @RequestPart(value="requestPart", required=false) SimpleBean namedRequestPart,
 					   @Valid @RequestPart("requestPart") SimpleBean validRequestPart,
@@ -342,7 +435,10 @@ public class RequestPartMethodArgumentResolverTests {
 					   Part part,
 					   @RequestPart("part") List<Part> partList,
 					   @RequestPart("part") Part[] partArray,
-					   @RequestParam MultipartFile requestParamAnnot) {
+					   @RequestParam MultipartFile requestParamAnnot,
+					   Optional<MultipartFile> optionalMultipartFile,
+					   Optional<Part> optionalPart,
+					   @RequestPart("requestPart") Optional<SimpleBean> optionalRequestPart) {
 	}
 
 }