Polishing

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/AbstractNamedValueMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -146,8 +146,9 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 		if (info.name.isEmpty()) {
 			name = parameter.getParameterName();
 			if (name == null) {
-				throw new IllegalArgumentException("Name for argument type [" + parameter.getParameterType().getName() +
-						"] not available, and parameter name information not found in class file either.");
+				throw new IllegalArgumentException(
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -126,7 +126,6 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 			catch (TypeMismatchException ex) {
 				throw new MethodArgumentTypeMismatchException(arg, ex.getRequiredType(),
 						namedValueInfo.name, parameter, ex.getCause());
-
 			}
 		}
 
@@ -165,8 +164,8 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 			name = parameter.getParameterName();
 			if (name == null) {
 				throw new IllegalArgumentException(
-						"Name for argument type [" + parameter.getNestedParameterType().getName() +
-						"] not available, and parameter name information not found in class file either.");
+						"Name for argument of type [" + parameter.getNestedParameterType().getName() +
+						"] not specified, and parameter name information not found in class file either.");
 			}
 		}
 		String defaultValue = (ValueConstants.DEFAULT_NONE.equals(info.defaultValue) ? null : info.defaultValue);

spring-web/src/main/java/org/springframework/web/method/support/InvocableHandlerMethod.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -47,12 +47,12 @@ import org.springframework.web.method.HandlerMethod;
  */
 public class InvocableHandlerMethod extends HandlerMethod {
 
-	private WebDataBinderFactory dataBinderFactory;
-
-	private HandlerMethodArgumentResolverComposite argumentResolvers = new HandlerMethodArgumentResolverComposite();
+	private HandlerMethodArgumentResolverComposite resolvers = new HandlerMethodArgumentResolverComposite();
 
 	private ParameterNameDiscoverer parameterNameDiscoverer = new DefaultParameterNameDiscoverer();
 
+	private WebDataBinderFactory dataBinderFactory;
+
 
 	/**
 	 * Create an instance from a {@code HandlerMethod}.
@@ -82,20 +82,11 @@ public class InvocableHandlerMethod extends HandlerMethod {
 	}
 
 
-	/**
-	 * Set the {@link WebDataBinderFactory} to be passed to argument resolvers allowing them to create
-	 * a {@link WebDataBinder} for data binding and type conversion purposes.
-	 * @param dataBinderFactory the data binder factory.
-	 */
-	public void setDataBinderFactory(WebDataBinderFactory dataBinderFactory) {
-		this.dataBinderFactory = dataBinderFactory;
-	}
-
 	/**
 	 * Set {@link HandlerMethodArgumentResolver}s to use to use for resolving method argument values.
 	 */
 	public void setHandlerMethodArgumentResolvers(HandlerMethodArgumentResolverComposite argumentResolvers) {
-		this.argumentResolvers = argumentResolvers;
+		this.resolvers = argumentResolvers;
 	}
 
 	/**
@@ -107,6 +98,14 @@ public class InvocableHandlerMethod extends HandlerMethod {
 		this.parameterNameDiscoverer = parameterNameDiscoverer;
 	}
 
+	/**
+	 * Set the {@link WebDataBinderFactory} to be passed to argument resolvers allowing them
+	 * to create a {@link WebDataBinder} for data binding and type conversion purposes.
+	 */
+	public void setDataBinderFactory(WebDataBinderFactory dataBinderFactory) {
+		this.dataBinderFactory = dataBinderFactory;
+	}
+
 
 	/**
 	 * Invoke the method after resolving its argument values in the context of the given request.
@@ -153,9 +152,9 @@ public class InvocableHandlerMethod extends HandlerMethod {
 			if (args[i] != null) {
 				continue;
 			}
-			if (this.argumentResolvers.supportsParameter(parameter)) {
+			if (this.resolvers.supportsParameter(parameter)) {
 				try {
-					args[i] = this.argumentResolvers.resolveArgument(
+					args[i] = this.resolvers.resolveArgument(
 							parameter, mavContainer, request, this.dataBinderFactory);
 					continue;
 				}

spring-web/src/main/java/org/springframework/web/multipart/support/MissingServletRequestPartException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -26,7 +26,7 @@ import org.springframework.web.multipart.MultipartResolver;
  *
  * <p>This may be because the request is not a multipart/form-data request,
  * because the part is not present in the request, or because the web
- * application is not configured correctly for processing  multipart requests,
+ * application is not configured correctly for processing multipart requests,
  * e.g. no {@link MultipartResolver}.
  *
  * @author Rossen Stoyanchev
@@ -35,17 +35,24 @@ import org.springframework.web.multipart.MultipartResolver;
 @SuppressWarnings("serial")
 public class MissingServletRequestPartException extends ServletException {
 
-	private final String partName;
+	private final String requestPartName;
 
 
-	public MissingServletRequestPartException(String partName) {
-		super("Required request part '" + partName + "' is not present");
-		this.partName = partName;
+	/**
+	 * Constructor for MissingServletRequestPartException.
+	 * @param requestPartName the name of the missing part of the multipart request
+	 */
+	public MissingServletRequestPartException(String requestPartName) {
+		super("Required request part '" + requestPartName + "' is not present");
+		this.requestPartName = requestPartName;
 	}
 
 
+	/**
+	 * Return the name of the offending part of the multipart request.
+	 */
 	public String getRequestPartName() {
-		return this.partName;
+		return this.requestPartName;
 	}
 
 }

spring-web/src/main/java/org/springframework/web/multipart/support/RequestPartServletServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -45,59 +45,62 @@ public class RequestPartServletServerHttpRequest extends ServletServerHttpReques
 
 	private final MultipartHttpServletRequest multipartRequest;
 
-	private final String partName;
+	private final String requestPartName;
 
-	private final HttpHeaders headers;
+	private final HttpHeaders multipartHeaders;
 
 
 	/**
 	 * Create a new {@code RequestPartServletServerHttpRequest} instance.
 	 * @param request the current servlet request
-	 * @param partName the name of the part to adapt to the {@link ServerHttpRequest} contract
+	 * @param requestPartName the name of the part to adapt to the {@link ServerHttpRequest} contract
 	 * @throws MissingServletRequestPartException if the request part cannot be found
 	 * @throws MultipartException if MultipartHttpServletRequest cannot be initialized
 	 */
-	public RequestPartServletServerHttpRequest(HttpServletRequest request, String partName)
+	public RequestPartServletServerHttpRequest(HttpServletRequest request, String requestPartName)
 			throws MissingServletRequestPartException {
 
 		super(request);
 
 		this.multipartRequest = MultipartResolutionDelegate.asMultipartHttpServletRequest(request);
-		this.partName = partName;
+		this.requestPartName = requestPartName;
 
-		this.headers = this.multipartRequest.getMultipartHeaders(this.partName);
-		if (this.headers == null) {
-			throw new MissingServletRequestPartException(partName);
+		HttpHeaders multipartHeaders = this.multipartRequest.getMultipartHeaders(requestPartName);
+		if (multipartHeaders == null) {
+			throw new MissingServletRequestPartException(requestPartName);
 		}
+		this.multipartHeaders = multipartHeaders;
 	}
 
 
 	@Override
 	public HttpHeaders getHeaders() {
-		return this.headers;
+		return this.multipartHeaders;
 	}
 
-
 	@Override
 	public InputStream getBody() throws IOException {
+		// Prefer Servlet Part resolution to cover file as well as parameter streams
 		if (this.multipartRequest instanceof StandardMultipartHttpServletRequest) {
 			try {
-				return this.multipartRequest.getPart(this.partName).getInputStream();
+				return this.multipartRequest.getPart(this.requestPartName).getInputStream();
 			}
 			catch (Exception ex) {
-				throw new MultipartException("Could not parse multipart servlet request", ex);
+				throw new MultipartException("Failed to retrieve request part '" + this.requestPartName + "'", ex);
 			}
 		}
-		else {
-			MultipartFile file = this.multipartRequest.getFile(this.partName);
-			if (file != null) {
-				return file.getInputStream();
-			}
-			else {
-				String paramValue = this.multipartRequest.getParameter(this.partName);
-				return new ByteArrayInputStream(paramValue.getBytes(determineEncoding()));
-			}
+
+		// Spring-style distinction between MultipartFile and String parameters
+		MultipartFile file = this.multipartRequest.getFile(this.requestPartName);
+		if (file != null) {
+			return file.getInputStream();
+		}
+		String paramValue = this.multipartRequest.getParameter(this.requestPartName);
+		if (paramValue != null) {
+			return new ByteArrayInputStream(paramValue.getBytes(determineEncoding()));
 		}
+
+		throw new IllegalStateException("No body available for request part '" + this.requestPartName + "'");
 	}
 
 	private String determineEncoding() {