Update intializer for the reactive servlet adapter

Move the AbstractServletHttpHandlerAdapterInitializer together with
the other two base classes in spring-web-reactive. Since the
interface is in the web package, this avoids a package cycle.
Also add a mention in the reference.

Issue: SPR-14713

spring-web-reactive/src/main/java/org/springframework/web/reactive/support/AbstractAnnotationConfigDispatcherHandlerInitializer.java

@@ -28,8 +28,7 @@ import org.springframework.web.reactive.DispatcherHandler;
  * {@link org.springframework.context.annotation.Configuration @Configuration} classes in the
  * servlet context, wrapping it in a {@link ServletHttpHandlerAdapter}.
  *
- * <p>Concrete implementations are required to implement {@link #getConfigClasses()} and
- * {@link #getServletMapping()}.
+ * <p>Concrete implementations are required to implement {@link #getConfigClasses()}.
  * Further template and customization methods are provided by
  * {@link AbstractDispatcherHandlerInitializer}.
  *

spring-web-reactive/src/main/java/org/springframework/web/reactive/support/AbstractDispatcherHandlerInitializer.java

@@ -130,10 +130,9 @@ public abstract class AbstractDispatcherHandlerInitializer implements WebApplica
 	/**
 	 * Refresh the given application context, if necessary.
 	 */
-	protected void refreshApplicationContext(ApplicationContext applicationContext) {
-		if (applicationContext instanceof ConfigurableApplicationContext) {
-			ConfigurableApplicationContext cac =
-					(ConfigurableApplicationContext) applicationContext;
+	protected void refreshApplicationContext(ApplicationContext context) {
+		if (context instanceof ConfigurableApplicationContext) {
+			ConfigurableApplicationContext cac = (ConfigurableApplicationContext) context;
 			if (!cac.isActive()) {
 				cac.refresh();
 			}

spring-web-reactive/src/main/java/org/springframework/web/reactive/support/AbstractServletHttpHandlerAdapterInitializer.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.http.server.reactive.support;
+package org.springframework.web.reactive.support;
 
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
@@ -24,7 +24,6 @@ import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ServletHttpHandlerAdapter;
 import org.springframework.util.Assert;
 import org.springframework.web.WebApplicationInitializer;
-import org.springframework.web.context.WebApplicationContext;
 
 /**
  * Base class for {@link org.springframework.web.WebApplicationInitializer}
@@ -47,6 +46,7 @@ public abstract class AbstractServletHttpHandlerAdapterInitializer
 	 */
 	public static final String DEFAULT_SERVLET_NAME = "http-handler-adapter";
 
+
 	@Override
 	public void onStartup(ServletContext servletContext) throws ServletException {
 		registerHandlerAdapter(servletContext);
@@ -104,7 +104,7 @@ public abstract class AbstractServletHttpHandlerAdapterInitializer
 	protected abstract HttpHandler createHttpHandler();
 
 	/**
-	 * Create a {@link ServletHttpHandlerAdapter}  with the specified {@link WebApplicationContext}.
+	 * Create a {@link ServletHttpHandlerAdapter}  with the specified .
 	 * <p>Default implementation returns a {@code ServletHttpHandlerAdapter} with the provided
 	 * {@code httpHandler}.
 	 */

spring-web/src/main/java/org/springframework/http/server/reactive/support/package-info.java

@@ -1,21 +0,0 @@
-/*
- * Copyright 2002-2016 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.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/**
- * Support classes for Spring's reactive HTTP server abstraction.
- */
-
-package org.springframework.http.server.reactive.support;

src/asciidoc/web-reactive.adoc

@@ -198,7 +198,7 @@ An `HttpHandler` can then be installed in each supported runtime:
 [source,java,indent=0]
 [subs="verbatim,quotes"]
 ----
-// Tomcat and Jetty
+// Tomcat and Jetty (also see notes below)
 HttpServlet servlet = new ServletHttpHandlerAdapter(httpHandler);
 ...
 
@@ -218,6 +218,16 @@ Undertow server = Undertow.builder().addHttpListener(port, host).setHandler(http
 server.start();
 ----
 
+[NOTE]
+====
+For Servlet runtimes you can use the `AbstractAnnotationConfigDispatcherHandlerInitializer`,
+which as a `WebApplicationInitializer` is auto-detected by Servlet containers
+and it registers for you the `ServletHttpHandlerAdapter` shown above.
+Only implement one method to point to your Spring Java configuration classes.
+====
+
+
+
 
 [[web-reactive-getting-started-M1]]
 === Extent of Support in 5.0 M1