Update advice on RestTemplate

Closes gh-24503

Author: rstoyanchev

spring-web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 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.
@@ -72,13 +72,10 @@
  * addition to the generalized {@code exchange} and {@code execute} methods that
  * support of less frequent cases.
  *
- * <p><strong>NOTE:</strong> As of 5.0, the non-blocking, reactive
- * {@code org.springframework.web.reactive.client.WebClient} offers a
- * modern alternative to the {@code RestTemplate} with efficient support for
- * both sync and async, as well as streaming scenarios. The {@code RestTemplate}
- * will be deprecated in a future version and will not have major new features
- * added going forward. See the WebClient section of the Spring Framework reference
- * documentation for more details and example code.
+ * <p><strong>NOTE:</strong> As of 5.0 this class is in maintenance mode, with
+ * only minor requests for changes and bugs to be accepted going forward. Please,
+ * consider using the {@code org.springframework.web.reactive.client.WebClient}
+ * which has a more modern API and supports sync, async, and streaming scenarios.
  *
  * @author Arjen Poutsma
  * @author Brian Clozel

src/docs/asciidoc/integration.adoc

@@ -920,10 +920,10 @@ method API.
 * <<web-reactive.adoc#webflux-client, WebClient>>: a non-blocking, reactive alternative
 that supports both synchronous and asynchronous as well as streaming scenarios.
 
-NOTE: As of 5.0, the non-blocking, reactive `WebClient` offers a modern alternative to the
-`RestTemplate` with efficient support for both synchronous and asynchronous as well as streaming
-scenarios. The `RestTemplate` will be deprecated in a future version and will not have
-major new features added going forward.
+NOTE: As of 5.0 the `RestTemplate` is in maintenance mode, with only minor requests for
+changes and bugs to be accepted going forward. Please, consider using the
+<<web-reactive.adoc#webflux-client, WebClient>> which offers a more modern API and
+supports sync, async, and streaming scenarios.
 
 
 [[rest-resttemplate]]

src/docs/asciidoc/web/webmvc-client.adoc

@@ -13,12 +13,10 @@ This section describes options for client-side access to REST endpoints.
 Spring REST client and exposes a simple, template-method API over underlying HTTP client
 libraries.
 
-NOTE: As of 5.0, the non-blocking, reactive `WebClient` offers a modern alternative to the
-`RestTemplate`, with efficient support for both
-<<web-reactive.adoc#webflux-client-synchronous, synchronous and asynchronous>>, as well as
-streaming scenarios. The `RestTemplate` will be deprecated in a future version and will
-not have major new features added going forward.
-
+NOTE: As of 5.0 the `RestTemplate` is in maintenance mode, with only minor requests for
+changes and bugs to be accepted going forward. Please, consider using the
+<<web-reactive.adoc#webflux-client, WebClient>> which offers a more modern API and
+supports sync, async, and streaming scenarios.
 
 See <<integration.adoc#rest-client-access, REST Endpoints>> for details.