Drop @WebServlet annotation

Issue: SPR-16591

spring-web/src/main/java/org/springframework/http/server/reactive/JettyHttpHandlerAdapter.java

 /*
- * 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.
@@ -20,7 +20,6 @@ import java.io.IOException;
 import java.nio.ByteBuffer;
 import javax.servlet.AsyncContext;
 import javax.servlet.ServletResponse;
-import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServletResponse;
 
 import org.eclipse.jetty.server.HttpOutput;
@@ -34,8 +33,8 @@ import org.springframework.core.io.buffer.DataBufferFactory;
  *
  * @author Violeta Georgieva
  * @since 5.0
+ * @see org.springframework.web.server.adapter.AbstractReactiveWebInitializer
  */
-@WebServlet(asyncSupported = true)
 public class JettyHttpHandlerAdapter extends ServletHttpHandlerAdapter {
 
 	public JettyHttpHandlerAdapter(HttpHandler httpHandler) {

spring-web/src/main/java/org/springframework/http/server/reactive/ServletHttpHandlerAdapter.java

@@ -29,7 +29,6 @@ import javax.servlet.ServletException;
 import javax.servlet.ServletRegistration;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
-import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -52,8 +51,8 @@ import org.springframework.util.Assert;
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
  * @since 5.0
+ * @see org.springframework.web.server.adapter.AbstractReactiveWebInitializer
  */
-@WebServlet(asyncSupported = true)
 @SuppressWarnings("serial")
 public class ServletHttpHandlerAdapter implements Servlet {
 

spring-web/src/main/java/org/springframework/http/server/reactive/TomcatHttpHandlerAdapter.java

@@ -21,7 +21,6 @@ import java.nio.ByteBuffer;
 import javax.servlet.AsyncContext;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
-import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -39,8 +38,8 @@ import org.springframework.util.Assert;
  *
  * @author Violeta Georgieva
  * @since 5.0
+ * @see org.springframework.web.server.adapter.AbstractReactiveWebInitializer
  */
-@WebServlet(asyncSupported = true)
 public class TomcatHttpHandlerAdapter extends ServletHttpHandlerAdapter {
 
 

spring-web/src/test/java/org/springframework/http/server/reactive/bootstrap/JettyHttpServer.java

@@ -41,6 +41,7 @@ public class JettyHttpServer extends AbstractHttpServer {
 
 		ServletHttpHandlerAdapter servlet = createServletAdapter();
 		ServletHolder servletHolder = new ServletHolder(servlet);
+		servletHolder.setAsyncSupported(true);
 
 		this.contextHandler = new ServletContextHandler(this.jettyServer, "", false, false);
 		this.contextHandler.addServlet(servletHolder, "/");

spring-web/src/test/java/org/springframework/http/server/reactive/bootstrap/TomcatHttpServer.java

@@ -73,7 +73,7 @@ public class TomcatHttpServer extends AbstractHttpServer {
 
 		File base = new File(System.getProperty("java.io.tmpdir"));
 		Context rootContext = tomcatServer.addContext(this.contextPath, base.getAbsolutePath());
-		Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+		Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet).setAsyncSupported(true);
 		rootContext.addServletMappingDecoded(this.servletMapping, "httpHandlerServlet");
 		if (wsListener != null) {
 			rootContext.addApplicationListener(wsListener.getName());