Checkstyle changes

* Upgrade to Checkstyle 9.0
* apply some JavaDocs rules
* Fix JavaDocs rules violations
* Some other minor clean up in the affected classes

spring-integration-http/src/main/java/org/springframework/integration/http/dsl/HttpInboundEndpointSupportSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2019 the original author or authors.
+ * Copyright 2017-2021 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.
@@ -41,6 +41,9 @@ import org.springframework.validation.Validator;
 import org.springframework.web.bind.annotation.RequestMethod;
 
 /**
+ * @param <S> the target spec extension type.
+ * @param <E> the target endpoint type.
+ *
  * @author Artem Bilan
  * @author Gary Russell
  *
@@ -68,7 +71,7 @@ public abstract class HttpInboundEndpointSupportSpec<S extends HttpInboundEndpoi
 	}
 
 	/**
-	 * Provide a {@link Consumer} for configuring {@link RequestMapping} via {@link RequestMappingSpec}
+	 * Provide a {@link Consumer} for configuring {@link RequestMapping} via {@link RequestMappingSpec}.
 	 * @param mapping the {@link Consumer} to configure {@link RequestMappingSpec}.
 	 * @return the spec
 	 * @see RequestMapping
@@ -79,7 +82,7 @@ public abstract class HttpInboundEndpointSupportSpec<S extends HttpInboundEndpoi
 	}
 
 	/**
-	 * Provide a {@link Consumer} for configuring {@link CrossOrigin} via {@link CrossOriginSpec}
+	 * Provide a {@link Consumer} for configuring {@link CrossOrigin} via {@link CrossOriginSpec}.
 	 * @param crossOrigin the {@link Consumer} to configure {@link CrossOriginSpec}.
 	 * @return the spec
 	 * @see CrossOrigin

spring-integration-http/src/main/java/org/springframework/integration/http/multipart/MultipartFileReader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -23,6 +23,8 @@ import org.springframework.web.multipart.MultipartFile;
 /**
  * Strategy for reading {@link MultipartFile} content.
  *
+ * @param <T> the expected file content type.
+ *
  * @author Mark Fisher
  *
  * @since 2.0
@@ -30,8 +32,7 @@ import org.springframework.web.multipart.MultipartFile;
 public interface MultipartFileReader<T> {
 
 	/**
-	 * Reads {@link MultipartFile} content.
-	 *
+	 * Read {@link MultipartFile} content.
 	 * @param multipartFile The multipart file.
 	 * @return The result of reading the file.
 	 * @throws IOException Any IOException.

spring-integration-http/src/main/java/org/springframework/integration/http/multipart/MultipartHttpInputMessage.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -28,6 +28,8 @@ import org.springframework.web.multipart.MultipartRequest;
 
 /**
  * @author Mark Fisher
+ * @author Artem Bilan
+ *
  * @since 2.0
  */
 public class MultipartHttpInputMessage extends ServletServerHttpRequest implements MultipartRequest {
@@ -67,18 +69,8 @@ public class MultipartHttpInputMessage extends ServletServerHttpRequest implemen
 		return this.multipartServletRequest.getParameterMap();
 	}
 
-	/**
-	 * Once we depend upon Spring 3.1 as a minimum, this code can be changed to:
-	 *     this.multipartServletRequest.getMultipartContentType(String paramOrFileName)
-	 */
 	public String getMultipartContentType(String paramOrFileName) {
-		MultipartFile file = getFile(paramOrFileName);
-		if (file != null) {
-			return file.getContentType();
-		}
-		else {
-			throw new UnsupportedOperationException("unable to retrieve multipart content-type for parameter");
-		}
+		return this.multipartServletRequest.getMultipartContentType(paramOrFileName);
 	}
 
 }

spring-integration-http/src/main/java/org/springframework/integration/http/outbound/AbstractHttpRequestExecutingMessageHandler.java

@@ -338,9 +338,6 @@ public abstract class AbstractHttpRequestExecutingMessageHandler extends Abstrac
 		return replyBuilder.copyHeaders(headers);
 	}
 
-	/**
-	 * Convert Set-Cookie to Cookie
-	 */
 	private void doConvertSetCookie(Map<String, Object> headers) {
 		String keyName = null;
 		for (String key : headers.keySet()) {
@@ -464,7 +461,7 @@ public abstract class AbstractHttpRequestExecutingMessageHandler extends Abstrac
 		return true;
 	}
 
-	/**
+	/*
 	 * If all keys are Strings, and some values are not Strings we'll consider
 	 * the Map to be multipart/form-data
 	 */

spring-integration-http/src/main/java/org/springframework/integration/http/outbound/HttpRequestExecutingMessageHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -93,7 +93,7 @@ public class HttpRequestExecutingMessageHandler extends AbstractHttpRequestExecu
 	}
 
 	/**
-	 * Create a handler that will send requests to the provided URI using a provided RestTemplate
+	 * Create a handler that will send requests to the provided URI using a provided RestTemplate.
 	 * @param uri The URI.
 	 * @param restTemplate The rest template.
 	 */
@@ -107,8 +107,8 @@ public class HttpRequestExecutingMessageHandler extends AbstractHttpRequestExecu
 		Assert.hasText(uri, "URI is required");
 	}
 
-	/**
-	 * Create a handler that will send requests to the provided URI using a provided RestTemplate
+	/**4
+	 * Create a handler that will send requests to the provided URI using a provided RestTemplate.
 	 * @param uriExpression A SpEL Expression that can be resolved against the message object and
 	 * {@link org.springframework.beans.factory.BeanFactory}.
 	 * @param restTemplate The rest template.