Apply getAcceptLanguageAsLocale and encodeUrl

Apply the new HttpHeaders#getAcceptLanguageAsLocale() in places where
it was hardcoded or defaulting.

Apply ServerHttpResponse.encodeUrl in RequestContext.

Issue: SPR-15024

spring-web-reactive/src/main/java/org/springframework/web/reactive/function/server/DefaultServerResponseBuilder.java

@@ -317,7 +317,8 @@ class DefaultServerResponseBuilder implements ServerResponse.BodyBuilder {
 			ServerHttpResponse response = exchange.getResponse();
 			writeStatusAndHeaders(response);
 			MediaType contentType = exchange.getResponse().getHeaders().getContentType();
-			Locale locale = Locale.ENGLISH; // TODO: resolve locale
+			Locale acceptLocale = exchange.getRequest().getHeaders().getAcceptLanguageAsLocale();
+			Locale locale = (acceptLocale != null ? acceptLocale : Locale.getDefault());
 			Stream<ViewResolver> viewResolverStream = strategies.viewResolvers().get();
 			return Flux.fromStream(viewResolverStream)
 					.concatMap(viewResolver -> viewResolver.resolveViewName(this.name, locale))

spring-web-reactive/src/main/java/org/springframework/web/reactive/result/view/RequestContext.java

@@ -76,7 +76,9 @@ public class RequestContext {
 		this.model = model;
 		this.messageSource = messageSource;
 		this.defaultHtmlEscape = null; // TODO
-		this.locale = Locale.getDefault(); // TODO
+
+		Locale acceptLocale = exchange.getRequest().getHeaders().getAcceptLanguageAsLocale();
+		this.locale = acceptLocale != null ? acceptLocale : Locale.getDefault();
 		this.timeZone = TimeZone.getDefault(); // TODO
 	}
 
@@ -102,7 +104,6 @@ public class RequestContext {
 
 	/**
 	 * Return the current Locale.
-	 * TODO: currently this is Locale.getDefault()
 	 */
 	public final Locale getLocale() {
 		return this.locale;
@@ -118,7 +119,6 @@ public class RequestContext {
 
 	/**
 	 * Change the current locale to the specified one.
-	 * TODO: currently simply change the internal field
 	 */
 	public void changeLocale(Locale locale) {
 		this.locale = locale;
@@ -126,7 +126,6 @@ public class RequestContext {
 
 	/**
 	 * Change the current locale to the specified locale and time zone context.
-	 * TODO: currently simply change the internal fields
 	 */
 	public void changeLocale(Locale locale, TimeZone timeZone) {
 		this.locale = locale;
@@ -176,8 +175,7 @@ public class RequestContext {
 	 */
 	public String getContextUrl(String relativeUrl) {
 		String url = getContextPath() + relativeUrl;
-		// TODO: this.response.encodeURL(url)
-		return url;
+		return getExchange().getResponse().encodeUrl(url);
 	}
 
 	/**
@@ -194,8 +192,7 @@ public class RequestContext {
 		String url = getContextPath() + relativeUrl;
 		UriTemplate template = new UriTemplate(url);
 		url = template.expand(params).toASCIIString();
-		// TODO: this.response.encodeURL(url)
-		return url;
+		return getExchange().getResponse().encodeUrl(url);
 	}
 
 	/**

spring-web-reactive/src/main/java/org/springframework/web/reactive/result/view/ViewResolutionResultHandler.java

@@ -212,7 +212,9 @@ public class ViewResolutionResultHandler extends AbstractHandlerResultHandler
 
 					Mono<List<View>> viewsMono;
 					Model model = result.getModel();
-					Locale locale = Locale.getDefault(); // TODO
+
+					Locale acceptLocale = exchange.getRequest().getHeaders().getAcceptLanguageAsLocale();
+					Locale locale = acceptLocale != null ? acceptLocale : Locale.getDefault();
 
 					Class<?> clazz = elementType.getRawClass();
 					if (clazz == null) {

spring-web-reactive/src/main/java/org/springframework/web/reactive/result/view/freemarker/FreeMarkerView.java

@@ -170,7 +170,10 @@ public class FreeMarkerView extends AbstractUrlBasedView {
 		if (logger.isDebugEnabled()) {
 			logger.debug("Rendering FreeMarker template [" + getUrl() + "].");
 		}
-		Locale locale = Locale.getDefault(); // TODO
+
+		Locale acceptLocale = exchange.getRequest().getHeaders().getAcceptLanguageAsLocale();
+		Locale locale = acceptLocale != null ? acceptLocale : Locale.getDefault();
+
 		DataBuffer dataBuffer = exchange.getResponse().bufferFactory().allocateBuffer();
 		try {
 			Charset charset = getCharset(contentType).orElse(getDefaultCharset());