WebFlux support for LocaleContext related arguments

Issue: SPR-15998

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/ServerWebExchangeArgumentResolver.java

@@ -16,12 +16,19 @@
 
 package org.springframework.web.reactive.result.method.annotation;
 
+import java.time.ZoneId;
+import java.util.Locale;
+import java.util.TimeZone;
+
+import org.springframework.context.i18n.LocaleContext;
+import org.springframework.context.i18n.TimeZoneAwareLocaleContext;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ReactiveAdapterRegistry;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpRequest;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.lang.Nullable;
 import org.springframework.web.reactive.BindingContext;
 import org.springframework.web.reactive.result.method.HandlerMethodArgumentResolverSupport;
 import org.springframework.web.reactive.result.method.SyncHandlerMethodArgumentResolver;
@@ -36,6 +43,9 @@ import org.springframework.web.util.UriComponentsBuilder;
  * <li>{@link ServerHttpRequest}
  * <li>{@link ServerHttpResponse}
  * <li>{@link HttpMethod}
+ * <li>{@link Locale}
+ * <li>{@link TimeZone}
+ * <li>{@link ZoneId}
  * <li>{@link UriBuilder} or {@link UriComponentsBuilder} -- for building URL's
  * relative to the current request
  * </ul>
@@ -63,6 +73,9 @@ public class ServerWebExchangeArgumentResolver extends HandlerMethodArgumentReso
 						ServerHttpRequest.class.isAssignableFrom(type) ||
 						ServerHttpResponse.class.isAssignableFrom(type) ||
 						HttpMethod.class == type ||
+						Locale.class == type ||
+						TimeZone.class == type ||
+						ZoneId.class == type ||
 						UriBuilder.class == type || UriComponentsBuilder.class == type);
 	}
 
@@ -83,6 +96,19 @@ public class ServerWebExchangeArgumentResolver extends HandlerMethodArgumentReso
 		else if (HttpMethod.class == paramType) {
 			return exchange.getRequest().getMethod();
 		}
+		else if (Locale.class == paramType) {
+			return exchange.getLocaleContext().getLocale();
+		}
+		else if (TimeZone.class == paramType) {
+			LocaleContext localeContext = exchange.getLocaleContext();
+			TimeZone timeZone = getTimeZone(localeContext);
+			return timeZone != null ? timeZone : TimeZone.getDefault();
+		}
+		else if (ZoneId.class == paramType) {
+			LocaleContext localeContext = exchange.getLocaleContext();
+			TimeZone timeZone = getTimeZone(localeContext);
+			return timeZone != null ? timeZone.toZoneId() : ZoneId.systemDefault();
+		}
 		else if (UriBuilder.class == paramType || UriComponentsBuilder.class == paramType) {
 			return UriComponentsBuilder.fromHttpRequest(exchange.getRequest());
 		}
@@ -93,4 +119,13 @@ public class ServerWebExchangeArgumentResolver extends HandlerMethodArgumentReso
 		}
 	}
 
+	@Nullable
+	private TimeZone getTimeZone(LocaleContext localeContext) {
+		TimeZone timeZone = null;
+		if (localeContext instanceof TimeZoneAwareLocaleContext) {
+			timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
+		}
+		return timeZone;
+	}
+
 }