Remove unintended dependency on Servlet API in SockJS

Add a factory method in ServerHttpRequest for creating a
ServerHttpAsyncRequestControl.

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

@@ -23,7 +23,7 @@ package org.springframework.http.server;
  * @author Rossen Stoyanchev
  * @since 4.0
  */
-public interface ServerHttpAsyncResponseControl {
+public interface ServerHttpAsyncRequestControl {
 
 	/**
 	 * Enable asynchronous processing after which the response remains open until a call
@@ -42,7 +42,7 @@ public interface ServerHttpAsyncResponseControl {
 	/**
 	 * Whether asynchronous request processing has been started.
 	 */
-	boolean hasStarted();
+	boolean isStarted();
 
 	/**
 	 * Causes asynchronous request processing to be completed.

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

@@ -28,6 +28,7 @@ import org.springframework.util.MultiValueMap;
  * Represents a server-side HTTP request.
  *
  * @author Arjen Poutsma
+ * @author Rossen Stoyanchev
  * @since 3.0
  */
 public interface ServerHttpRequest extends HttpRequest, HttpInputMessage {
@@ -39,7 +40,6 @@ public interface ServerHttpRequest extends HttpRequest, HttpInputMessage {
 
 	/**
 	 * Return the cookie values parsed from the "Cookie" request header.
-	 * @return the cookies
 	 */
 	Map<String, Cookie> getCookies();
 
@@ -60,4 +60,10 @@ public interface ServerHttpRequest extends HttpRequest, HttpInputMessage {
 	 */
 	String getRemoteAddress();
 
+	/**
+	 * Return a control that allows putting the request in asynchronous mode so the
+	 * response remains open until closed explicitly from the current or another thread.
+	 */
+	ServerHttpAsyncRequestControl getAsyncRequestControl(ServerHttpResponse response);
+
 }

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

@@ -29,12 +29,12 @@ import org.springframework.util.Assert;
 
 
 /**
- * A {@link ServerHttpAsyncResponseControl} to use on Servlet containers (Servlet 3.0+).
+ * A {@link ServerHttpAsyncRequestControl} to use on Servlet containers (Servlet 3.0+).
  *
  * @author Rossen Stoyanchev
  * @since 4.0
  */
-public class ServletServerHttpAsyncRequestControl implements ServerHttpAsyncResponseControl, AsyncListener {
+public class ServletServerHttpAsyncRequestControl implements ServerHttpAsyncRequestControl, AsyncListener {
 
 	private static long NO_TIMEOUT_VALUE = Long.MIN_VALUE;
 
@@ -52,27 +52,24 @@ public class ServletServerHttpAsyncRequestControl implements ServerHttpAsyncResp
 	 * {@link ServletServerHttpRequest} and {@link ServletServerHttpResponse}
 	 * respectively.
 	 */
-	public ServletServerHttpAsyncRequestControl(ServerHttpRequest request, ServerHttpResponse response) {
+	public ServletServerHttpAsyncRequestControl(ServletServerHttpRequest request, ServletServerHttpResponse response) {
 
 		Assert.notNull(request, "request is required");
 		Assert.notNull(response, "response is required");
 
-		Assert.isInstanceOf(ServletServerHttpRequest.class, request);
-		Assert.isInstanceOf(ServletServerHttpResponse.class, response);
-
-		this.request = (ServletServerHttpRequest) request;
-		this.response = (ServletServerHttpResponse) response;
-
-		Assert.isTrue(this.request.getServletRequest().isAsyncSupported(),
+		Assert.isTrue(request.getServletRequest().isAsyncSupported(),
 				"Async support must be enabled on a servlet and for all filters involved " +
 				"in async request processing. This is done in Java code using the Servlet API " +
 				"or by adding \"<async-supported>true</async-supported>\" to servlet and " +
 				"filter declarations in web.xml. Also you must use a Servlet 3.0+ container");
+
+		this.request = request;
+		this.response = response;
 	}
 
 
 	@Override
-	public boolean hasStarted() {
+	public boolean isStarted() {
 		return ((this.asyncContext != null) && this.request.getServletRequest().isAsyncStarted());
 	}
 
@@ -91,7 +88,7 @@ public class ServletServerHttpAsyncRequestControl implements ServerHttpAsyncResp
 
 		Assert.state(!isCompleted(), "Async processing has already completed");
 
-		if (hasStarted()) {
+		if (isStarted()) {
 			return;
 		}
 
@@ -108,7 +105,7 @@ public class ServletServerHttpAsyncRequestControl implements ServerHttpAsyncResp
 
 	@Override
 	public void complete() {
-		if (hasStarted() && !isCompleted()) {
+		if (isStarted() && !isCompleted()) {
 			this.asyncContext.complete();
 		}
 	}

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

@@ -72,6 +72,7 @@ public class ServletServerHttpRequest implements ServerHttpRequest {
 
 	private MultiValueMap<String, String> queryParams;
 
+	private ServerHttpAsyncRequestControl asyncRequestControl;
 
 	/**
 	 * Construct a new instance of the ServletServerHttpRequest based on the given {@link HttpServletRequest}.
@@ -238,4 +239,14 @@ public class ServletServerHttpRequest implements ServerHttpRequest {
 		return new ByteArrayInputStream(bos.toByteArray());
 	}
 
+	@Override
+	public ServerHttpAsyncRequestControl getAsyncRequestControl(ServerHttpResponse response) {
+		if (this.asyncRequestControl == null) {
+			Assert.isInstanceOf(ServletServerHttpResponse.class, response);
+			ServletServerHttpResponse servletServerResponse = (ServletServerHttpResponse) response;
+			this.asyncRequestControl = new ServletServerHttpAsyncRequestControl(this, servletServerResponse);
+		}
+		return this.asyncRequestControl;
+	}
+
 }