Polish Forwarded header support

spring-web/src/main/java/org/springframework/web/filter/ForwardedHeaderFilter.java

@@ -42,19 +42,19 @@ import org.springframework.web.util.UriComponentsBuilder;
 import org.springframework.web.util.UrlPathHelper;
 
 /**
- * Extract values from "Forwarded" and "X-Forwarded-*" headers in order to wrap
- * and override the following from the request and response:
- * {@link HttpServletRequest#getServerName() getServerName()},
- * {@link HttpServletRequest#getServerPort() getServerPort()},
- * {@link HttpServletRequest#getScheme() getScheme()},
- * {@link HttpServletRequest#isSecure() isSecure()}, and
- * {@link HttpServletResponse#sendRedirect(String) sendRedirect(String)}.
- * In effect the wrapped request and response reflect the client-originated
- * protocol and address.
+ * Extract values from "Forwarded" and "X-Forwarded-*" headers, wrap the request
+ * and response, and make they reflect the client-originated protocol and
+ * address in the following methods:
+ * <ul>
+ * <li>{@link HttpServletRequest#getServerName() getServerName()}
+ * <li>{@link HttpServletRequest#getServerPort() getServerPort()}
+ * <li>{@link HttpServletRequest#getScheme() getScheme()}
+ * <li>{@link HttpServletRequest#isSecure() isSecure()}
+ * <li>{@link HttpServletResponse#sendRedirect(String) sendRedirect(String)}.
+ * </ul>
  *
- * <p><strong>Note:</strong> This filter can also be used in a
- * {@link #setRemoveOnly removeOnly} mode where "Forwarded" and "X-Forwarded-*"
- * headers are only eliminated without being used.
+ * <p>This filter can also be used in a {@link #setRemoveOnly removeOnly} mode
+ * where "Forwarded" and "X-Forwarded-*" headers are eliminated, and not used.
  *
  * @author Rossen Stoyanchev
  * @author Eddú Meléndez
@@ -117,7 +117,7 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 
 
 	@Override
-	protected boolean shouldNotFilter(HttpServletRequest request) throws ServletException {
+	protected boolean shouldNotFilter(HttpServletRequest request) {
 		for (String headerName : FORWARDED_HEADER_NAMES) {
 			if (request.getHeader(headerName) != null) {
 				return false;
@@ -141,15 +141,18 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 			FilterChain filterChain) throws ServletException, IOException {
 
 		if (this.removeOnly) {
-			ForwardedHeaderRemovingRequest theRequest = new ForwardedHeaderRemovingRequest(request);
-			filterChain.doFilter(theRequest, response);
+			ForwardedHeaderRemovingRequest wrappedRequest = new ForwardedHeaderRemovingRequest(request);
+			filterChain.doFilter(wrappedRequest, response);
 		}
 		else {
-			HttpServletRequest theRequest = new ForwardedHeaderExtractingRequest(request, this.pathHelper);
-			HttpServletResponse theResponse = (this.relativeRedirects ?
+			HttpServletRequest wrappedRequest =
+					new ForwardedHeaderExtractingRequest(request, this.pathHelper);
+
+			HttpServletResponse wrappedResponse = this.relativeRedirects ?
 					RelativeRedirectResponseWrapper.wrapIfNecessary(response, HttpStatus.SEE_OTHER) :
-					new ForwardedHeaderExtractingResponse(response, theRequest));
-			filterChain.doFilter(theRequest, theResponse);
+					new ForwardedHeaderExtractingResponse(response, wrappedRequest);
+
+			filterChain.doFilter(wrappedRequest, wrappedResponse);
 		}
 	}
 
@@ -221,7 +224,8 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 
 		private final String requestUrl;
 
-		public ForwardedHeaderExtractingRequest(HttpServletRequest request, UrlPathHelper pathHelper) {
+
+		ForwardedHeaderExtractingRequest(HttpServletRequest request, UrlPathHelper pathHelper) {
 			super(request);
 
 			HttpRequest httpRequest = new ServletServerHttpRequest(request);
@@ -257,6 +261,7 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 			return prefix;
 		}
 
+
 		@Override
 		@Nullable
 		public String getScheme() {
@@ -302,11 +307,13 @@ public class ForwardedHeaderFilter extends OncePerRequestFilter {
 
 		private final HttpServletRequest request;
 
-		public ForwardedHeaderExtractingResponse(HttpServletResponse response, HttpServletRequest request) {
+
+		ForwardedHeaderExtractingResponse(HttpServletResponse response, HttpServletRequest request) {
 			super(response);
 			this.request = request;
 		}
 
+
 		@Override
 		public void sendRedirect(String location) throws IOException {
 

spring-web/src/main/java/org/springframework/web/filter/reactive/ForwardedHeaderFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -31,17 +31,16 @@ import org.springframework.web.server.WebFilterChain;
 import org.springframework.web.util.UriComponentsBuilder;
 
 /**
- * Extract values from "Forwarded" and "X-Forwarded-*" headers in order to change
- * and override {@link ServerHttpRequest#getURI()}.
- * In effect the request URI will reflect the client-originated
+ * Extract values from "Forwarded" and "X-Forwarded-*" headers, and use them to
+ * override {@link ServerHttpRequest#getURI()} to reflect the client-originated
  * protocol and address.
  *
- * <p><strong>Note:</strong> This filter can also be used in a
- * {@link #setRemoveOnly removeOnly} mode where "Forwarded" and "X-Forwarded-*"
- * headers are only eliminated without being used.
+ * <p>This filter can also be used in a {@link #setRemoveOnly removeOnly} mode
+ * where "Forwarded" and "X-Forwarded-*" headers are eliminated, and not used.
+ *
  * @author Arjen Poutsma
- * @see <a href="https://tools.ietf.org/html/rfc7239">https://tools.ietf.org/html/rfc7239</a>
  * @since 5.0
+ * @see <a href="https://tools.ietf.org/html/rfc7239">https://tools.ietf.org/html/rfc7239</a>
  */
 public class ForwardedHeaderFilter implements WebFilter {
 
@@ -55,8 +54,10 @@ public class ForwardedHeaderFilter implements WebFilter {
 		FORWARDED_HEADER_NAMES.add("X-Forwarded-Prefix");
 	}
 
+
 	private boolean removeOnly;
 
+
 	/**
 	 * Enables mode in which any "Forwarded" or "X-Forwarded-*" headers are
 	 * removed only and the information in them ignored.
@@ -66,6 +67,7 @@ public class ForwardedHeaderFilter implements WebFilter {
 		this.removeOnly = removeOnly;
 	}
 
+
 	@Override
 	public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
 
@@ -73,31 +75,29 @@ public class ForwardedHeaderFilter implements WebFilter {
 			return chain.filter(exchange);
 		}
 
+		ServerWebExchange mutatedExchange;
+
 		if (this.removeOnly) {
-			ServerWebExchange withoutForwardHeaders = exchange.mutate()
-					.request(builder -> builder.headers(
-							headers -> {
-								for (String headerName : FORWARDED_HEADER_NAMES) {
-									headers.remove(headerName);
-								}
-							})).build();
-			return chain.filter(withoutForwardHeaders);
+			mutatedExchange = exchange.mutate().request(builder ->
+					builder.headers(headers -> {
+						FORWARDED_HEADER_NAMES.forEach(headers::remove);
+					}))
+					.build();
 		}
 		else {
 			URI uri = UriComponentsBuilder.fromHttpRequest(exchange.getRequest()).build().toUri();
 			String prefix = getForwardedPrefix(exchange.getRequest().getHeaders());
 
-			ServerWebExchange withChangedUri = exchange.mutate()
-					.request(builder -> {
-						builder.uri(uri);
-						if (prefix != null) {
-							builder.path(prefix + uri.getPath());
-							builder.contextPath(prefix);
-						}
-					}).build();
-			return chain.filter(withChangedUri);
+			mutatedExchange = exchange.mutate().request(builder -> {
+				builder.uri(uri);
+				if (prefix != null) {
+					builder.path(prefix + uri.getPath());
+					builder.contextPath(prefix);
+				}
+			}).build();
 		}
 
+		return chain.filter(mutatedExchange);
 	}
 
 	private boolean shouldNotFilter(ServerHttpRequest request) {