Minor refactoring + polish reactive WebSocket support

Rename classes not specific to Tomcat:
TomcatWebSocketSession -> StandardWebSocketSession
TomcatWebSocketHandlerAdapter -> StandardWebSocketHandlerAdapter

WebSocketSessionSupport is renamed to AbstractWebSocketSession since it
actually is a WebSocketSession and pre-implements a number of methods.

ServerEndpointRegistration is now package private (mainly for use in
upgrade strategies) and renamed to DefaultServerEndpointConfig.

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/CloseStatus.java

@@ -23,11 +23,10 @@ import org.springframework.util.ObjectUtils;
  * Representation of WebSocket "close" status codes and reasons. Status codes
  * in the 1xxx range are pre-defined by the protocol.
  *
- * <p>See <a href="https://tools.ietf.org/html/rfc6455#section-7.4.1">
- *     RFC 6455, Section 7.4.1 "Defined Status Codes"</a>.
- *
  * @author Rossen Stoyanchev
  * @since 5.0
+ * @see <a href="https://tools.ietf.org/html/rfc6455#section-7.4.1">
+ *     RFC 6455, Section 7.4.1 "Defined Status Codes"</a>
  */
 public final class CloseStatus {
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/HandshakeInfo.java

@@ -24,10 +24,12 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.util.Assert;
 
 /**
- * Simple container of information from a WebSocket handshake request.
+ * Simple container of information related to the handshake request that started
+ * the {@link WebSocketSession} session.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
+ * @see WebSocketSession#getHandshakeInfo()
  */
 public class HandshakeInfo {
 
@@ -35,31 +37,41 @@ public class HandshakeInfo {
 
 	private final HttpHeaders headers;
 
-	private final Mono<Principal> principal;
+	private final Mono<Principal> principalMono;
 
 
-	public HandshakeInfo(URI uri, HttpHeaders headers, Mono<Principal> principal) {
+	public HandshakeInfo(URI uri, HttpHeaders headers, Mono<Principal> principalMono) {
 		Assert.notNull(uri, "URI is required.");
 		Assert.notNull(headers, "HttpHeaders are required.");
-		Assert.notNull(principal, "Prinicpal is required.");
+		Assert.notNull(principalMono, "Principal is required.");
 		this.uri = uri;
 		this.headers = headers;
-		this.principal = principal;
+		this.principalMono = principalMono;
 	}
 
 
+	/**
+	 * Return the URL for the WebSocket endpoint.
+	 */
 	public URI getUri() {
 		return this.uri;
 	}
 
+	/**
+	 * Return the headers from the handshake HTTP request.
+	 */
 	public HttpHeaders getHeaders() {
 		return this.headers;
 	}
 
+	/**
+	 * Return the principal associated with the handshake HTTP request, if any.
+	 */
 	public Mono<Principal> getPrincipal() {
-		return this.principal;
+		return this.principalMono;
 	}
 
+
 	@Override
 	public String toString() {
 		return "HandshakeInfo[uri=" + this.uri + ", headers=" + this.headers + "]";

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/WebSocketHandler.java

@@ -21,7 +21,7 @@ import java.util.List;
 import reactor.core.publisher.Mono;
 
 /**
- * Handler for a WebSocket-style session interaction.
+ * Handler for a WebSocket session.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
@@ -37,9 +37,10 @@ public interface WebSocketHandler {
 	}
 
 	/**
-	 * Handle the given WebSocket session.
-	 * @param session the session
-	 * @return signals completion for session handling
+	 * Handle the WebSocket session.
+	 * @param session the session to handle
+	 * @return completion {@code Mono<Void>} to indicate the outcome of the
+	 * WebSocket session handling.
 	 */
 	Mono<Void> handle(WebSocketSession session);
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/WebSocketMessage.java

@@ -24,7 +24,9 @@ import org.springframework.util.ObjectUtils;
 
 /**
  * Representation of a WebSocket message.
- * Use one of the static factory methods in this class to create a message.
+ * <p>See static factory methods in {@link WebSocketSession} for creating messages
+ * with the {@link org.springframework.core.io.buffer.DataBufferFactory
+ * DataBufferFactory} for the session.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
@@ -37,15 +39,10 @@ public class WebSocketMessage {
 
 
 	/**
-	 * Constructor for a WebSocketMessage. To create, see factory methods:
-	 * <ul>
-	 * <li>{@link WebSocketSession#textMessage}
-	 * <li>{@link WebSocketSession#binaryMessage}
-	 * <li>{@link WebSocketSession#pingMessage}
-	 * <li>{@link WebSocketSession#pongMessage}
-	 * </ul>
-	 * <p>Alternatively use {@link WebSocketSession#bufferFactory()} to create
-	 * the payload and then invoke this constructor.
+	 * Constructor for a WebSocketMessage.
+	 * <p>See static factory methods in {@link WebSocketSession} or alternatively
+	 * use {@link WebSocketSession#bufferFactory()} to create the payload and
+	 * then invoke this constructor.
 	 */
 	public WebSocketMessage(Type type, DataBuffer payload) {
 		Assert.notNull(type, "'type' must not be null");
@@ -81,7 +78,7 @@ public class WebSocketMessage {
 
 	/**
 	 * Retain the data buffer for the message payload, which is useful on
-	 * runtimes with pooled buffers, e.g. Netty. A shortcut for:
+	 * runtimes (e.g. Netty) with pooled buffers. A shortcut for:
 	 * <pre>
 	 * DataBuffer payload = message.getPayload();
 	 * DataBufferUtils.retain(payload);
@@ -94,8 +91,8 @@ public class WebSocketMessage {
 	}
 
 	/**
-	 * Release the payload {@code DataBuffer} which is useful on runtimes with
-	 * pooled buffers such as Netty. Effectively a shortcut for:
+	 * Release the payload {@code DataBuffer} which is useful on runtimes
+	 * (e.g. Netty) with pooled buffers such as Netty. A shortcut for:
 	 * <pre>
 	 * DataBuffer payload = message.getPayload();
 	 * DataBufferUtils.release(payload);

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/WebSocketSession.java

@@ -25,7 +25,15 @@ import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferFactory;
 
 /**
- * Representation for a WebSocket session.
+ * Represents a WebSocket session with Reactive Streams input and output.
+ *
+ * <p>On the server side a WebSocket session can be handled by mapping
+ * requests to a {@link WebSocketHandler} and ensuring there is a
+ * {@link org.springframework.web.reactive.socket.server.support.WebSocketHandlerAdapter
+ * WebSocketHandlerAdapter} strategy registered in Spring configuration.
+ * On the client side a {@link WebSocketHandler} can be provided to a
+ * {@link org.springframework.web.reactive.socket.client.WebSocketClient
+ * WebSocketClient}.
  *
  * @author Rossen Stoyanchev
  * @since 5.0

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/AbstractListenerWebSocketSession.java

@@ -33,13 +33,15 @@ import org.springframework.web.reactive.socket.WebSocketMessage.Type;
 import org.springframework.web.reactive.socket.WebSocketSession;
 
 /**
- * Base class for Listener-based {@link WebSocketSession} adapters.
+ * Base class for {@link WebSocketSession} implementations that bridge between
+ * event-listener WebSocket APIs (e.g. Java WebSocket API JSR-356, Jetty,
+ * Undertow) and Reactive Streams.
  *
  * @author Violeta Georgieva
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-public abstract class AbstractListenerWebSocketSession<T> extends WebSocketSessionSupport<T> {
+public abstract class AbstractListenerWebSocketSession<T> extends AbstractWebSocketSession<T> {
 
 	/**
 	 * The "back-pressure" buffer size to use if the underlying WebSocket API

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/AbstractWebSocketSession.java

@@ -28,20 +28,19 @@ import reactor.core.publisher.Mono;
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferFactory;
 import org.springframework.util.Assert;
-import org.springframework.web.reactive.socket.CloseStatus;
 import org.springframework.web.reactive.socket.HandshakeInfo;
 import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketSession;
 
 /**
- * Base class for {@link WebSocketSession} implementations wrapping and
- * delegating to the native WebSocket session (or connection) of the underlying
- * WebSocket runtime.
+ * Convenient base class for {@link WebSocketSession} implementations that
+ * holds common fields and exposes accessors. Also implements the
+ * {@code WebSocketMessage} factory methods.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-public abstract class WebSocketSessionSupport<T> implements WebSocketSession {
+public abstract class AbstractWebSocketSession<T> implements WebSocketSession {
 
 	protected final Log logger = LogFactory.getLog(getClass());
 
@@ -58,7 +57,7 @@ public abstract class WebSocketSessionSupport<T> implements WebSocketSession {
 	/**
 	 * Create a new instance and associate the given attributes with it.
 	 */
-	protected WebSocketSessionSupport(T delegate, String id, HandshakeInfo handshakeInfo,
+	protected AbstractWebSocketSession(T delegate, String id, HandshakeInfo handshakeInfo,
 			DataBufferFactory bufferFactory) {
 
 		Assert.notNull(delegate, "Native session is required.");
@@ -73,10 +72,7 @@ public abstract class WebSocketSessionSupport<T> implements WebSocketSession {
 	}
 
 
-	/**
-	 * Return the native session of the underlying runtime.
-	 */
-	public T getDelegate() {
+	protected T getDelegate() {
 		return this.delegate;
 	}
 
@@ -105,6 +101,9 @@ public abstract class WebSocketSessionSupport<T> implements WebSocketSession {
 		return this.bufferFactory;
 	}
 
+
+	// WebSocketMessage factory methods
+
 	@Override
 	public WebSocketMessage textMessage(String payload) {
 		byte[] bytes = payload.getBytes(StandardCharsets.UTF_8);
@@ -130,16 +129,6 @@ public abstract class WebSocketSessionSupport<T> implements WebSocketSession {
 		return new WebSocketMessage(WebSocketMessage.Type.PONG, payload);
 	}
 
-	@Override
-	public final Mono<Void> close(CloseStatus status) {
-		if (logger.isDebugEnabled()) {
-			logger.debug("Closing " + this);
-		}
-		return closeInternal(status);
-	}
-
-	protected abstract Mono<Void> closeInternal(CloseStatus status);
-
 
 	@Override
 	public String toString() {

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/JettyWebSocketHandlerAdapter.java

@@ -40,10 +40,11 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketMessage.Type;
 
 /**
- * Jetty {@code WebSocketHandler} implementation adapting and
- * delegating to a Spring {@link WebSocketHandler}.
+ * Jetty {@link WebSocket @WebSocket} handler that delegates events to a
+ * reactive {@link WebSocketHandler} and its session.
  * 
  * @author Violeta Georgieva
+ * @author Rossen Stoyanchev
  * @since 5.0
  */
 @WebSocket
@@ -51,47 +52,47 @@ public class JettyWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupport
 
 	private static final ByteBuffer EMPTY_PAYLOAD = ByteBuffer.wrap(new byte[0]);
 
-	private JettyWebSocketSession session;
+	private JettyWebSocketSession delegateSession;
 
 
-	public JettyWebSocketHandlerAdapter(HandshakeInfo handshakeInfo, DataBufferFactory bufferFactory,
-			WebSocketHandler delegate) {
+	public JettyWebSocketHandlerAdapter(WebSocketHandler delegate, HandshakeInfo info,
+			DataBufferFactory bufferFactory) {
 
-		super(handshakeInfo, bufferFactory, delegate);
+		super(delegate, info, bufferFactory);
 	}
 
 
 	@OnWebSocketConnect
 	public void onWebSocketConnect(Session session) {
-		this.session = new JettyWebSocketSession(session, getHandshakeInfo(), getBufferFactory());
+		this.delegateSession = new JettyWebSocketSession(session, getHandshakeInfo(), bufferFactory());
 		HandlerResultSubscriber subscriber = new HandlerResultSubscriber();
-		getDelegate().handle(this.session).subscribe(subscriber);
+		getDelegate().handle(this.delegateSession).subscribe(subscriber);
 	}
 
 	@OnWebSocketMessage
 	public void onWebSocketText(String message) {
-		if (this.session != null) {
+		if (this.delegateSession != null) {
 			WebSocketMessage webSocketMessage = toMessage(Type.TEXT, message);
-			this.session.handleMessage(webSocketMessage.getType(), webSocketMessage);
+			this.delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
 		}
 	}
 
 	@OnWebSocketMessage
 	public void onWebSocketBinary(byte[] message, int offset, int length) {
-		if (this.session != null) {
+		if (this.delegateSession != null) {
 			ByteBuffer buffer = ByteBuffer.wrap(message, offset, length);
 			WebSocketMessage webSocketMessage = toMessage(Type.BINARY, buffer);
-			session.handleMessage(webSocketMessage.getType(), webSocketMessage);
+			delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
 		}
 	}
 
 	@OnWebSocketFrame
 	public void onWebSocketFrame(Frame frame) {
-		if (this.session != null) {
+		if (this.delegateSession != null) {
 			if (OpCode.PONG == frame.getOpCode()) {
 				ByteBuffer buffer = (frame.getPayload() != null ? frame.getPayload() : EMPTY_PAYLOAD);
 				WebSocketMessage webSocketMessage = toMessage(Type.PONG, buffer);
-				session.handleMessage(webSocketMessage.getType(), webSocketMessage);
+				delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
 			}
 		}
 	}
@@ -99,15 +100,15 @@ public class JettyWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupport
 	private <T> WebSocketMessage toMessage(Type type, T message) {
 		if (Type.TEXT.equals(type)) {
 			byte[] bytes = ((String) message).getBytes(StandardCharsets.UTF_8);
-			DataBuffer buffer = getBufferFactory().wrap(bytes);
+			DataBuffer buffer = bufferFactory().wrap(bytes);
 			return new WebSocketMessage(Type.TEXT, buffer);
 		}
 		else if (Type.BINARY.equals(type)) {
-			DataBuffer buffer = getBufferFactory().wrap((ByteBuffer) message);
+			DataBuffer buffer = bufferFactory().wrap((ByteBuffer) message);
 			return new WebSocketMessage(Type.BINARY, buffer);
 		}
 		else if (Type.PONG.equals(type)) {
-			DataBuffer buffer = getBufferFactory().wrap((ByteBuffer) message);
+			DataBuffer buffer = bufferFactory().wrap((ByteBuffer) message);
 			return new WebSocketMessage(Type.PONG, buffer);
 		}
 		else {
@@ -117,15 +118,15 @@ public class JettyWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupport
 
 	@OnWebSocketClose
 	public void onWebSocketClose(int statusCode, String reason) {
-		if (this.session != null) {
-			this.session.handleClose(new CloseStatus(statusCode, reason));
+		if (this.delegateSession != null) {
+			this.delegateSession.handleClose(new CloseStatus(statusCode, reason));
 		}
 	}
 
 	@OnWebSocketError
 	public void onWebSocketError(Throwable cause) {
-		if (this.session != null) {
-			this.session.handleError(cause);
+		if (this.delegateSession != null) {
+			this.delegateSession.handleError(cause);
 		}
 	}
 
@@ -144,15 +145,16 @@ public class JettyWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupport
 
 		@Override
 		public void onError(Throwable ex) {
-			if (session != null) {
-				session.close(new CloseStatus(CloseStatus.SERVER_ERROR.getCode(), ex.getMessage()));
+			if (delegateSession != null) {
+				int code = CloseStatus.SERVER_ERROR.getCode();
+				delegateSession.close(new CloseStatus(code, ex.getMessage()));
 			}
 		}
 
 		@Override
 		public void onComplete() {
-			if (session != null) {
-				session.close();
+			if (delegateSession != null) {
+				delegateSession.close();
 			}
 		}
 	}

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/JettyWebSocketSession.java

@@ -32,10 +32,11 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketSession;
 
 /**
- * Spring {@link WebSocketSession} adapter for Jetty's
- * {@link org.eclipse.jetty.websocket.api.Session}.
+ * Spring {@link WebSocketSession} implementation that adapts to a Jetty
+ * WebSocket {@link org.eclipse.jetty.websocket.api.Session}.
  * 
  * @author Violeta Georgieva
+ * @author Rossen Stoyanchev
  * @since 5.0
  */
 public class JettyWebSocketSession extends AbstractListenerWebSocketSession<Session> {
@@ -86,7 +87,7 @@ public class JettyWebSocketSession extends AbstractListenerWebSocketSession<Sess
 	}
 
 	@Override
-	protected Mono<Void> closeInternal(CloseStatus status) {
+	public Mono<Void> close(CloseStatus status) {
 		getDelegate().close(status.getCode(), status.getReason());
 		return Mono.empty();
 	}

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/NettyWebSocketSessionSupport.java

@@ -36,12 +36,14 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketSession;
 
 /**
- * Base class for Netty-based {@link WebSocketSession} adapters.
+ * Base class for Netty-based {@link WebSocketSession} adapters that provides
+ * convenience methods to convert Netty {@link WebSocketFrame}s to and from
+ * {@link WebSocketMessage}s.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-public abstract class NettyWebSocketSessionSupport<T> extends WebSocketSessionSupport<T> {
+public abstract class NettyWebSocketSessionSupport<T> extends AbstractWebSocketSession<T> {
 
 	private static final Map<Class<?>, WebSocketMessage.Type> MESSAGE_TYPES;
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/ReactorNettyWebSocketSession.java

@@ -31,8 +31,8 @@ import org.springframework.web.reactive.socket.WebSocketSession;
 
 
 /**
- * Spring {@link WebSocketSession} adapter for RxNetty's
- * {@link io.reactivex.netty.protocol.http.ws.WebSocketConnection}.
+ * Spring {@link WebSocketSession} implementation that adapts to Reactor Netty's
+ * WebSocket {@link NettyInbound} and {@link NettyOutbound}.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
@@ -42,9 +42,9 @@ public class ReactorNettyWebSocketSession
 
 
 	public ReactorNettyWebSocketSession(NettyInbound inbound, NettyOutbound outbound,
-			HandshakeInfo handshakeInfo, NettyDataBufferFactory bufferFactory) {
+			HandshakeInfo info, NettyDataBufferFactory bufferFactory) {
 
-		super(new WebSocketConnection(inbound, outbound), handshakeInfo, bufferFactory);
+		super(new WebSocketConnection(inbound, outbound), info, bufferFactory);
 	}
 
 
@@ -64,10 +64,11 @@ public class ReactorNettyWebSocketSession
 	}
 
 	@Override
-	protected Mono<Void> closeInternal(CloseStatus status) {
+	public Mono<Void> close(CloseStatus status) {
 		return Mono.error(new UnsupportedOperationException(
-				"Currently in Reactor Netty applications are expected to use the Cancellation" +
-						"returned from subscribing to the input Flux to close the WebSocket session."));
+				"Currently in Reactor Netty applications are expected to use the " +
+						"Cancellation returned from subscribing to the \"receive\"-side Flux " +
+						"in order to close the WebSocket session."));
 	}
 
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/RxNettyWebSocketSession.java

@@ -31,7 +31,7 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketSession;
 
 /**
- * Spring {@link WebSocketSession} adapter for RxNetty's
+ * Spring {@link WebSocketSession} implementation that adapts to the RxNetty
  * {@link io.reactivex.netty.protocol.http.ws.WebSocketConnection}.
  *
  * @author Rossen Stoyanchev
@@ -40,7 +40,9 @@ import org.springframework.web.reactive.socket.WebSocketSession;
 public class RxNettyWebSocketSession extends NettyWebSocketSessionSupport<WebSocketConnection> {
 
 
-	public RxNettyWebSocketSession(WebSocketConnection conn, HandshakeInfo info, NettyDataBufferFactory factory) {
+	public RxNettyWebSocketSession(WebSocketConnection conn, HandshakeInfo info,
+			NettyDataBufferFactory factory) {
+
 		super(conn, info, factory);
 	}
 
@@ -60,7 +62,7 @@ public class RxNettyWebSocketSession extends NettyWebSocketSessionSupport<WebSoc
 	}
 
 	@Override
-	protected Mono<Void> closeInternal(CloseStatus status) {
+	public Mono<Void> close(CloseStatus status) {
 		Observable<Void> completion = getDelegate().close();
 		return Mono.from(RxReactiveStreams.toPublisher(completion));
 	}

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/StandardWebSocketHandlerAdapter.java

@@ -36,21 +36,22 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketMessage.Type;
 
 /**
- * Tomcat {@code WebSocketHandler} implementation adapting and
- * delegating to a Spring {@link WebSocketHandler}.
- * 
+ * Adapter for Java WebSocket API (JSR-356) {@link Endpoint} delegating events
+ * to a reactive {@link WebSocketHandler} and its session.
+ *
  * @author Violeta Georgieva
+ * @author Rossen Stoyanchev
  * @since 5.0
  */
-public class TomcatWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupport {
+public class StandardWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupport {
 
-	private TomcatWebSocketSession session;
+	private StandardWebSocketSession delegateSession;
 
 
-	public TomcatWebSocketHandlerAdapter(HandshakeInfo handshakeInfo, DataBufferFactory bufferFactory,
-			WebSocketHandler delegate) {
+	public StandardWebSocketHandlerAdapter(WebSocketHandler delegate, HandshakeInfo info,
+			DataBufferFactory bufferFactory) {
 
-		super(handshakeInfo, bufferFactory, delegate);
+		super(delegate, info, bufferFactory);
 	}
 
 
@@ -58,47 +59,42 @@ public class TomcatWebSocketHandlerAdapter extends WebSocketHandlerAdapterSuppor
 		return new StandardEndpoint();
 	}
 
-	private TomcatWebSocketSession getSession() {
-		return this.session;
-	}
-
 
 	private class StandardEndpoint extends Endpoint {
 
 		@Override
-		public void onOpen(Session session, EndpointConfig config) {
+		public void onOpen(Session nativeSession, EndpointConfig config) {
 
-			TomcatWebSocketHandlerAdapter.this.session = new TomcatWebSocketSession(
-					session, getHandshakeInfo(), getBufferFactory());
+			delegateSession = new StandardWebSocketSession(nativeSession, getHandshakeInfo(), bufferFactory());
 
-			session.addMessageHandler(String.class, message -> {
+			nativeSession.addMessageHandler(String.class, message -> {
 				WebSocketMessage webSocketMessage = toMessage(message);
-				getSession().handleMessage(webSocketMessage.getType(), webSocketMessage);
+				delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
 			});
-			session.addMessageHandler(ByteBuffer.class, message -> {
+			nativeSession.addMessageHandler(ByteBuffer.class, message -> {
 				WebSocketMessage webSocketMessage = toMessage(message);
-				getSession().handleMessage(webSocketMessage.getType(), webSocketMessage);
+				delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
 			});
-			session.addMessageHandler(PongMessage.class, message -> {
+			nativeSession.addMessageHandler(PongMessage.class, message -> {
 				WebSocketMessage webSocketMessage = toMessage(message);
-				getSession().handleMessage(webSocketMessage.getType(), webSocketMessage);
+				delegateSession.handleMessage(webSocketMessage.getType(), webSocketMessage);
 			});
 
 			HandlerResultSubscriber resultSubscriber = new HandlerResultSubscriber();
-			getDelegate().handle(TomcatWebSocketHandlerAdapter.this.session).subscribe(resultSubscriber);
+			getDelegate().handle(delegateSession).subscribe(resultSubscriber);
 		}
 
 		private <T> WebSocketMessage toMessage(T message) {
 			if (message instanceof String) {
 				byte[] bytes = ((String) message).getBytes(StandardCharsets.UTF_8);
-				return new WebSocketMessage(Type.TEXT, getBufferFactory().wrap(bytes));
+				return new WebSocketMessage(Type.TEXT, bufferFactory().wrap(bytes));
 			}
 			else if (message instanceof ByteBuffer) {
-				DataBuffer buffer = getBufferFactory().wrap((ByteBuffer) message);
+				DataBuffer buffer = bufferFactory().wrap((ByteBuffer) message);
 				return new WebSocketMessage(Type.BINARY, buffer);
 			}
 			else if (message instanceof PongMessage) {
-				DataBuffer buffer = getBufferFactory().wrap(((PongMessage) message).getApplicationData());
+				DataBuffer buffer = bufferFactory().wrap(((PongMessage) message).getApplicationData());
 				return new WebSocketMessage(Type.PONG, buffer);
 			}
 			else {
@@ -108,16 +104,16 @@ public class TomcatWebSocketHandlerAdapter extends WebSocketHandlerAdapterSuppor
 
 		@Override
 		public void onClose(Session session, CloseReason reason) {
-			if (getSession() != null) {
+			if (delegateSession != null) {
 				int code = reason.getCloseCode().getCode();
-				getSession().handleClose(new CloseStatus(code, reason.getReasonPhrase()));
+				delegateSession.handleClose(new CloseStatus(code, reason.getReasonPhrase()));
 			}
 		}
 
 		@Override
 		public void onError(Session session, Throwable exception) {
-			if (getSession() != null) {
-				getSession().handleError(exception);
+			if (delegateSession != null) {
+				delegateSession.handleError(exception);
 			}
 		}
 	}
@@ -136,15 +132,16 @@ public class TomcatWebSocketHandlerAdapter extends WebSocketHandlerAdapterSuppor
 
 		@Override
 		public void onError(Throwable ex) {
-			if (getSession() != null) {
-				getSession().close(new CloseStatus(CloseStatus.SERVER_ERROR.getCode(), ex.getMessage()));
+			if (delegateSession != null) {
+				int code = CloseStatus.SERVER_ERROR.getCode();
+				delegateSession.close(new CloseStatus(code, ex.getMessage()));
 			}
 		}
 
 		@Override
 		public void onComplete() {
-			if (getSession() != null) {
-				getSession().close();
+			if (delegateSession != null) {
+				delegateSession.close();
 			}
 		}
 	}

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/StandardWebSocketSession.java

@@ -38,12 +38,13 @@ import org.springframework.web.reactive.socket.WebSocketSession;
  * {@link javax.websocket.Session}.
  * 
  * @author Violeta Georgieva
+ * @author Rossen Stoyanchev
  * @since 5.0
  */
-public class TomcatWebSocketSession extends AbstractListenerWebSocketSession<Session> {
+public class StandardWebSocketSession extends AbstractListenerWebSocketSession<Session> {
 
 
-	public TomcatWebSocketSession(Session session, HandshakeInfo info, DataBufferFactory bufferFactory) {
+	public StandardWebSocketSession(Session session, HandshakeInfo info, DataBufferFactory bufferFactory) {
 		super(session, session.getId(), info, bufferFactory);
 	}
 
@@ -88,7 +89,7 @@ public class TomcatWebSocketSession extends AbstractListenerWebSocketSession<Ses
 	}
 
 	@Override
-	protected Mono<Void> closeInternal(CloseStatus status) {
+	public Mono<Void> close(CloseStatus status) {
 		try {
 			CloseReason.CloseCode code = CloseCodes.getCloseCode(status.getCode());
 			getDelegate().close(new CloseReason(code, status.getReason()));

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/UndertowWebSocketHandlerAdapter.java

@@ -38,33 +38,34 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketMessage.Type;
 
 /**
- * Undertow {@code WebSocketHandler} implementation adapting and
- * delegating to a Spring {@link WebSocketHandler}.
+ * Undertow {@link WebSocketConnectionCallback} implementation that adapts and
+ * delegates to a Spring {@link WebSocketHandler}.
  * 
  * @author Violeta Georgieva
+ * @author Rossen Stoyanchev
  * @since 5.0
  */
 public class UndertowWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupport
 		implements WebSocketConnectionCallback {
 
-	private UndertowWebSocketSession session;
+	private UndertowWebSocketSession delegateSession;
 
 
-	public UndertowWebSocketHandlerAdapter(HandshakeInfo handshakeInfo, DataBufferFactory bufferFactory,
-			WebSocketHandler delegate) {
+	public UndertowWebSocketHandlerAdapter(WebSocketHandler delegate, HandshakeInfo info,
+			DataBufferFactory bufferFactory) {
 
-		super(handshakeInfo, bufferFactory, delegate);
+		super(delegate, info, bufferFactory);
 	}
 
 
 	@Override
 	public void onConnect(WebSocketHttpExchange exchange, WebSocketChannel channel) {
-		this.session = new UndertowWebSocketSession(channel, getHandshakeInfo(), getBufferFactory());
+		this.delegateSession = new UndertowWebSocketSession(channel, getHandshakeInfo(), bufferFactory());
 		channel.getReceiveSetter().set(new UndertowReceiveListener());
 		channel.resumeReceives();
 
 		HandlerResultSubscriber resultSubscriber = new HandlerResultSubscriber();
-		getDelegate().handle(this.session).subscribe(resultSubscriber);
+		getDelegate().handle(this.delegateSession).subscribe(resultSubscriber);
 	}
 
 
@@ -72,44 +73,44 @@ public class UndertowWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupp
 
 		@Override
 		protected void onFullTextMessage(WebSocketChannel channel, BufferedTextMessage message) {
-			session.handleMessage(Type.TEXT, toMessage(Type.TEXT, message.getData()));
+			delegateSession.handleMessage(Type.TEXT, toMessage(Type.TEXT, message.getData()));
 		}
 
 		@Override
 		protected void onFullBinaryMessage(WebSocketChannel channel, BufferedBinaryMessage message) {
-			session.handleMessage(Type.BINARY, toMessage(Type.BINARY, message.getData().getResource()));
+			delegateSession.handleMessage(Type.BINARY, toMessage(Type.BINARY, message.getData().getResource()));
 			message.getData().free();
 		}
 
 		@Override
 		protected void onFullPongMessage(WebSocketChannel channel, BufferedBinaryMessage message) {
-			session.handleMessage(Type.PONG, toMessage(Type.PONG, message.getData().getResource()));
+			delegateSession.handleMessage(Type.PONG, toMessage(Type.PONG, message.getData().getResource()));
 			message.getData().free();
 		}
 
 		@Override
 		protected void onFullCloseMessage(WebSocketChannel channel, BufferedBinaryMessage message) {
 			CloseMessage closeMessage = new CloseMessage(message.getData().getResource());
-			session.handleClose(new CloseStatus(closeMessage.getCode(), closeMessage.getReason()));
+			delegateSession.handleClose(new CloseStatus(closeMessage.getCode(), closeMessage.getReason()));
 			message.getData().free();
 		}
 
 		@Override
 		protected void onError(WebSocketChannel channel, Throwable error) {
-			session.handleError(error);
+			delegateSession.handleError(error);
 		}
 
 		private <T> WebSocketMessage toMessage(Type type, T message) {
 			if (Type.TEXT.equals(type)) {
 				byte[] bytes = ((String) message).getBytes(StandardCharsets.UTF_8);
-				return new WebSocketMessage(Type.TEXT, getBufferFactory().wrap(bytes));
+				return new WebSocketMessage(Type.TEXT, bufferFactory().wrap(bytes));
 			}
 			else if (Type.BINARY.equals(type)) {
-				DataBuffer buffer = getBufferFactory().allocateBuffer().write((ByteBuffer[]) message);
+				DataBuffer buffer = bufferFactory().allocateBuffer().write((ByteBuffer[]) message);
 				return new WebSocketMessage(Type.BINARY, buffer);
 			}
 			else if (Type.PONG.equals(type)) {
-				DataBuffer buffer = getBufferFactory().allocateBuffer().write((ByteBuffer[]) message);
+				DataBuffer buffer = bufferFactory().allocateBuffer().write((ByteBuffer[]) message);
 				return new WebSocketMessage(Type.PONG, buffer);
 			}
 			else {
@@ -133,12 +134,13 @@ public class UndertowWebSocketHandlerAdapter extends WebSocketHandlerAdapterSupp
 
 		@Override
 		public void onError(Throwable ex) {
-			session.close(new CloseStatus(CloseStatus.SERVER_ERROR.getCode(), ex.getMessage()));
+			int code = CloseStatus.SERVER_ERROR.getCode();
+			delegateSession.close(new CloseStatus(code, ex.getMessage()));
 		}
 
 		@Override
 		public void onComplete() {
-			session.close();
+			delegateSession.close();
 		}
 	}
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/UndertowWebSocketSession.java

@@ -34,10 +34,11 @@ import org.springframework.web.reactive.socket.WebSocketMessage;
 import org.springframework.web.reactive.socket.WebSocketSession;
 
 /**
- * Spring {@link WebSocketSession} adapter for Undertow's
+ * Spring {@link WebSocketSession} implementation that adapts to an Undertow
  * {@link io.undertow.websockets.core.WebSocketChannel}.
  * 
  * @author Violeta Georgieva
+ * @author Rossen Stoyanchev
  * @since 5.0
  */
 public class UndertowWebSocketSession extends AbstractListenerWebSocketSession<WebSocketChannel> {
@@ -90,7 +91,7 @@ public class UndertowWebSocketSession extends AbstractListenerWebSocketSession<W
 	}
 
 	@Override
-	protected Mono<Void> closeInternal(CloseStatus status) {
+	public Mono<Void> close(CloseStatus status) {
 		CloseMessage cm = new CloseMessage(status.getCode(), status.getReason());
 		if (!getDelegate().isCloseFrameSent()) {
 			WebSockets.sendClose(cm, getDelegate(), null);

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/adapter/WebSocketHandlerAdapterSupport.java

@@ -21,44 +21,45 @@ import org.springframework.web.reactive.socket.HandshakeInfo;
 import org.springframework.web.reactive.socket.WebSocketHandler;
 
 /**
- * Base class for {@link WebSocketHandler} adapters to WebSocket handler APIs
- * of underlying runtimes.
+ * Base class for adapters from event-listener WebSocket APIs (e.g. Java
+ * WebSocket API JSR-356, Jetty, Undertow) to the Reactive Streams based
+ * {@link WebSocketHandler}.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
  */
 public abstract class WebSocketHandlerAdapterSupport {
 
-	private final HandshakeInfo handshakeInfo;
-
 	private final WebSocketHandler delegate;
 
+	private final HandshakeInfo handshakeInfo;
+
 	private final DataBufferFactory bufferFactory;
 
 
-	protected WebSocketHandlerAdapterSupport(HandshakeInfo handshakeInfo, DataBufferFactory bufferFactory,
-			WebSocketHandler handler) {
+	protected WebSocketHandlerAdapterSupport(WebSocketHandler delegate, HandshakeInfo info,
+			DataBufferFactory bufferFactory) {
 
-		Assert.notNull(handshakeInfo, "HandshakeInfo is required.");
+		Assert.notNull(delegate, "WebSocketHandler delegate is required");
+		Assert.notNull(info, "HandshakeInfo is required.");
 		Assert.notNull(bufferFactory, "DataBufferFactory is required");
-		Assert.notNull(handler, "WebSocketHandler handler is required");
 
-		this.handshakeInfo = handshakeInfo;
+		this.delegate = delegate;
+		this.handshakeInfo = info;
 		this.bufferFactory = bufferFactory;
-		this.delegate = handler;
 	}
 
 
-	protected HandshakeInfo getHandshakeInfo() {
-		return this.handshakeInfo;
-	}
-
 	protected WebSocketHandler getDelegate() {
 		return this.delegate;
 	}
 
+	protected HandshakeInfo getHandshakeInfo() {
+		return this.handshakeInfo;
+	}
+
 	@SuppressWarnings("unchecked")
-	protected <T extends DataBufferFactory> T getBufferFactory() {
+	protected <T extends DataBufferFactory> T bufferFactory() {
 		return (T) this.bufferFactory;
 	}
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/client/ReactorNettyWebSocketClient.java

@@ -34,7 +34,7 @@ import org.springframework.web.reactive.socket.WebSocketSession;
 import org.springframework.web.reactive.socket.adapter.ReactorNettyWebSocketSession;
 
 /**
- * A {@link WebSocketClient} based on Reactor Netty.
+ * A Reactor Netty based implementation of {@link WebSocketClient}.
  *
  * @author Rossen Stoyanchev
  * @since 5.0

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/client/RxNettyWebSocketClient.java

@@ -39,7 +39,7 @@ import org.springframework.web.reactive.socket.WebSocketSession;
 import org.springframework.web.reactive.socket.adapter.RxNettyWebSocketSession;
 
 /**
- * A {@link WebSocketClient} based on RxNetty.
+ * An RxNetty based implementation of {@link WebSocketClient}.
  *
  * @author Rossen Stoyanchev
  * @since 5.0

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/client/WebSocketClient.java

@@ -36,7 +36,7 @@ public interface WebSocketClient {
 	 * @param url the handshake url
 	 * @param handler the handler of the WebSocket session
 	 * @return completion {@code Mono<Void>} to indicate the outcome of the
-	 * WebSocket session handling
+	 * WebSocket session handling.
 	 */
 	Mono<Void> execute(URI url, WebSocketHandler handler);
 
@@ -46,7 +46,7 @@ public interface WebSocketClient {
 	 * @param headers custom headers for the handshake request
 	 * @param handler the handler of the WebSocket session
 	 * @return completion {@code Mono<Void>} to indicate the outcome of the
-	 * WebSocket session handling
+	 * WebSocket session handling.
 	 */
 	Mono<Void> execute(URI url, HttpHeaders headers, WebSocketHandler handler);
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/package-info.java

@@ -1,4 +1,4 @@
 /**
- * Abstractions and support classes for WebSocket interactions.
+ * Abstractions and support classes for reactive WebSocket interactions.
  */
 package org.springframework.web.reactive.socket;

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/RequestUpgradeStrategy.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.web.reactive.socket.server;
 
-import java.util.Map;
-
 import reactor.core.publisher.Mono;
 
 import org.springframework.http.server.reactive.ServerHttpRequest;
@@ -25,14 +23,13 @@ import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.server.ServerWebExchange;
 
 /**
- * A strategy for upgrading an HTTP request to a WebSocket interaction depending
- * on the underlying HTTP runtime.
+ * A strategy for upgrading an HTTP request to a WebSocket session depending
+ * on the underlying network runtime.
  *
  * <p>Typically there is one such strategy for every {@link ServerHttpRequest}
- * and {@link ServerHttpResponse} implementation type except in the case of
- * Servlet containers for which there is no standard API to upgrade a request.
- * JSR-356 does have programmatic endpoint registration but that is only
- * intended for use on startup and not per request.
+ * and {@link ServerHttpResponse} type except in the case of Servlet containers
+ * for which the standard Java WebSocket API JSR-356 does not define a way to
+ * upgrade a request so a custom strategy is needed for every Servlet container.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
@@ -40,11 +37,11 @@ import org.springframework.web.server.ServerWebExchange;
 public interface RequestUpgradeStrategy {
 
 	/**
-	 * Upgrade the request to a WebSocket interaction and adapt the given
-	 * Spring {@link WebSocketHandler} to the underlying runtime WebSocket API.
+	 * Upgrade to a WebSocket session and handle it with the given handler.
 	 * @param exchange the current exchange
-	 * @param webSocketHandler handler for WebSocket session
-	 * @return a completion Mono for the WebSocket session handling
+	 * @param webSocketHandler handler for the WebSocket session
+	 * @return completion {@code Mono<Void>} to indicate the outcome of the
+	 * WebSocket session handling.
 	 */
 	Mono<Void> upgrade(ServerWebExchange exchange, WebSocketHandler webSocketHandler);
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/WebSocketService.java

@@ -18,19 +18,18 @@ package org.springframework.web.reactive.socket.server;
 import reactor.core.publisher.Mono;
 
 import org.springframework.web.reactive.socket.WebSocketHandler;
-import org.springframework.web.reactive.socket.server.support.HandshakeWebSocketService;
 import org.springframework.web.server.ServerWebExchange;
 
 /**
  * A service to delegate WebSocket-related HTTP requests to.
  *
- * <p>For a straight-up WebSocket endpoint this means handling the initial
- * handshake request but for a SockJS endpoint this means handling all HTTP
+ * <p>For a WebSocket endpoint this means handling the initial WebSocket HTTP
+ * handshake request. For a SockJS endpoint it could mean handling all HTTP
  * requests defined in the SockJS protocol.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
- * @see HandshakeWebSocketService
+ * @see org.springframework.web.reactive.socket.server.support.HandshakeWebSocketService;
  */
 public interface WebSocketService {
 

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java

@@ -37,9 +37,10 @@ import org.springframework.web.server.MethodNotAllowedException;
 import org.springframework.web.server.ServerWebExchange;
 
 /**
- * A {@code WebSocketService} implementation that handles a WebSocket handshake
- * and upgrades to a WebSocket interaction through the configured or
- * auto-detected {@link RequestUpgradeStrategy}.
+ * {@code WebSocketService} implementation that handles a WebSocket HTTP
+ * handshake request by delegating to a {@link RequestUpgradeStrategy} which
+ * is either auto-detected (no-arg constructor) from the classpath but can
+ * also be explicitly configured.
  *
  * @author Rossen Stoyanchev
  * @since 5.0

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/support/WebSocketHandlerAdapter.java

@@ -26,9 +26,10 @@ import org.springframework.web.reactive.socket.server.WebSocketService;
 import org.springframework.web.server.ServerWebExchange;
 
 /**
- * {@code HandlerAdapter} that allows using a {@link WebSocketHandler} contract
- * with the generic {@link DispatcherHandler} mapping URLs directly to such
- * handlers. Requests are handled through the configured {@link WebSocketService}.
+ * {@link HandlerAdapter} that allows using a {@link WebSocketHandler} with the
+ * generic {@link DispatcherHandler} mapping URLs directly to such handlers.
+ * Requests are handled by delegating to the configured {@link WebSocketService}
+ * which by default is {@link HandshakeWebSocketService}.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
@@ -40,8 +41,7 @@ public class WebSocketHandlerAdapter implements HandlerAdapter {
 
 	/**
 	 * Default constructor that creates and uses a
-	 * {@link HandshakeWebSocketService} for a straight-up WebSocket interaction,
-	 * i.e. treating incoming requests as WebSocket handshake requests.
+	 * {@link HandshakeWebSocketService}.
 	 */
 	public WebSocketHandlerAdapter() {
 		this(new HandshakeWebSocketService());

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/upgrade/DefaultServerEndpointConfig.java

@@ -30,38 +30,34 @@ import javax.websocket.server.ServerEndpointConfig;
 import org.springframework.util.Assert;
 
 /**
- * An implementation of {@link javax.websocket.server.ServerEndpointConfig} for use in
- * Spring applications.
- *
- * <p>Class constructor accept a singleton {@link javax.websocket.Endpoint} instance.
- *
- * <p>This class also extends
- * {@link javax.websocket.server.ServerEndpointConfig.Configurator} to make it easier to
- * override methods for customizing the handshake process.
+ * Default implementation of {@link javax.websocket.server.ServerEndpointConfig}
+ * for use in {@code RequestUpgradeStrategy} implementations.
  *
  * @author Violeta Georgieva
+ * @author Rossen Stoyanchev
  * @since 5.0
  */
-public class ServerEndpointRegistration extends ServerEndpointConfig.Configurator 
+class DefaultServerEndpointConfig extends ServerEndpointConfig.Configurator
 		implements ServerEndpointConfig {
 
 	private final String path;
 
 	private final Endpoint endpoint;
 
+
 	/**
-	 * Create a new {@link ServerEndpointRegistration} instance from an
-	 * {@code javax.websocket.Endpoint} instance.
+	 * Constructor with a path and an {@code javax.websocket.Endpoint}.
 	 * @param path the endpoint path
 	 * @param endpoint the endpoint instance
 	 */
-	public ServerEndpointRegistration(String path, Endpoint endpoint) {
+	public DefaultServerEndpointConfig(String path, Endpoint endpoint) {
 		Assert.hasText(path, "path must not be empty");
 		Assert.notNull(endpoint, "endpoint must not be null");
 		this.path = path;
 		this.endpoint = endpoint;
 	}
 
+
 	@Override
 	public List<Class<? extends Encoder>> getEncoders() {
 		return new ArrayList<>();
@@ -82,10 +78,6 @@ public class ServerEndpointRegistration extends ServerEndpointConfig.Configurato
 		return this.endpoint.getClass();
 	}
 
-	public Endpoint getEndpoint() {
-		return this.endpoint;
-	}
-
 	@Override
 	public String getPath() {
 		return this.path;
@@ -108,13 +100,13 @@ public class ServerEndpointRegistration extends ServerEndpointConfig.Configurato
 
 	@SuppressWarnings("unchecked")
 	@Override
-	public <T> T getEndpointInstance(Class<T> endpointClass)
-			throws InstantiationException {
-		return (T) getEndpoint();
+	public <T> T getEndpointInstance(Class<T> endpointClass) throws InstantiationException {
+		return (T) this.endpoint;
 	}
 
 	@Override
 	public String toString() {
-		return "ServerEndpointRegistration for path '" + getPath() + "': " + getEndpointClass();
+		return "DefaultServerEndpointConfig for path '" + getPath() + "': " + getEndpointClass();
 	}
+
 }

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/upgrade/JettyRequestUpgradeStrategy.java

@@ -17,8 +17,6 @@
 package org.springframework.web.reactive.socket.server.upgrade;
 
 import java.io.IOException;
-import java.net.URI;
-import java.security.Principal;
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -30,14 +28,13 @@ import reactor.core.publisher.Mono;
 import org.springframework.context.Lifecycle;
 import org.springframework.core.NamedThreadLocal;
 import org.springframework.core.io.buffer.DataBufferFactory;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.http.server.reactive.ServletServerHttpRequest;
 import org.springframework.http.server.reactive.ServletServerHttpResponse;
 import org.springframework.util.Assert;
-import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.HandshakeInfo;
+import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.adapter.JettyWebSocketHandlerAdapter;
 import org.springframework.web.reactive.socket.server.RequestUpgradeStrategy;
 import org.springframework.web.server.ServerWebExchange;
@@ -111,13 +108,9 @@ public class JettyRequestUpgradeStrategy implements RequestUpgradeStrategy, Life
 		HttpServletRequest servletRequest = getHttpServletRequest(request);
 		HttpServletResponse servletResponse = getHttpServletResponse(response);
 
-		URI uri = request.getURI();
-		HttpHeaders headers = request.getHeaders();
-		Mono<Principal> principal = exchange.getPrincipal();
-		HandshakeInfo info = new HandshakeInfo(uri, headers, principal);
-		DataBufferFactory bufferFactory = response.bufferFactory();
-
-		JettyWebSocketHandlerAdapter adapter = new JettyWebSocketHandlerAdapter(info, bufferFactory, handler);
+		HandshakeInfo info = getHandshakeInfo(exchange);
+		DataBufferFactory factory = response.bufferFactory();
+		JettyWebSocketHandlerAdapter adapter = new JettyWebSocketHandlerAdapter(handler, info, factory);
 
 		startLazily(servletRequest);
 
@@ -148,6 +141,11 @@ public class JettyRequestUpgradeStrategy implements RequestUpgradeStrategy, Life
 		return ((ServletServerHttpResponse) response).getServletResponse();
 	}
 
+	private HandshakeInfo getHandshakeInfo(ServerWebExchange exchange) {
+		ServerHttpRequest request = exchange.getRequest();
+		return new HandshakeInfo(request.getURI(), request.getHeaders(), exchange.getPrincipal());
+	}
+
 	private void startLazily(HttpServletRequest request) {
 		if (this.servletContext != null) {
 			return;

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/upgrade/ReactorNettyRequestUpgradeStrategy.java

@@ -15,19 +15,16 @@
  */
 package org.springframework.web.reactive.socket.server.upgrade;
 
-import java.net.URI;
-import java.security.Principal;
 import java.util.List;
 
 import reactor.core.publisher.Mono;
 
 import org.springframework.core.io.buffer.NettyDataBufferFactory;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.server.reactive.ReactorServerHttpRequest;
 import org.springframework.http.server.reactive.ReactorServerHttpResponse;
+import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.util.StringUtils;
-import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.HandshakeInfo;
+import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.adapter.ReactorNettyWebSocketSession;
 import org.springframework.web.reactive.socket.server.RequestUpgradeStrategy;
 import org.springframework.web.server.ServerWebExchange;
@@ -43,13 +40,8 @@ public class ReactorNettyRequestUpgradeStrategy implements RequestUpgradeStrateg
 	@Override
 	public Mono<Void> upgrade(ServerWebExchange exchange, WebSocketHandler handler) {
 
-		ReactorServerHttpRequest request = (ReactorServerHttpRequest) exchange.getRequest();
 		ReactorServerHttpResponse response = (ReactorServerHttpResponse) exchange.getResponse();
-
-		URI uri = request.getURI();
-		HttpHeaders headers = request.getHeaders();
-		Mono<Principal> principal = exchange.getPrincipal();
-		HandshakeInfo handshakeInfo = new HandshakeInfo(uri, headers, principal);
+		HandshakeInfo handshakeInfo = getHandshakeInfo(exchange);
 		NettyDataBufferFactory bufferFactory = (NettyDataBufferFactory) response.bufferFactory();
 
 		String protocols = StringUtils.arrayToCommaDelimitedString(getSubProtocols(handler));
@@ -60,6 +52,11 @@ public class ReactorNettyRequestUpgradeStrategy implements RequestUpgradeStrateg
 						new ReactorNettyWebSocketSession(inbound, outbound, handshakeInfo, bufferFactory)));
 	}
 
+	private HandshakeInfo getHandshakeInfo(ServerWebExchange exchange) {
+		ServerHttpRequest request = exchange.getRequest();
+		return new HandshakeInfo(request.getURI(), request.getHeaders(), exchange.getPrincipal());
+	}
+
 	private static String[] getSubProtocols(WebSocketHandler webSocketHandler) {
 		List<String> subProtocols = webSocketHandler.getSubProtocols();
 		return subProtocols.toArray(new String[subProtocols.size()]);

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/upgrade/RxNettyRequestUpgradeStrategy.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.web.reactive.socket.server.upgrade;
 
-import java.net.URI;
-import java.security.Principal;
 import java.util.List;
 
 import reactor.core.publisher.Mono;
@@ -24,12 +22,11 @@ import rx.Observable;
 import rx.RxReactiveStreams;
 
 import org.springframework.core.io.buffer.NettyDataBufferFactory;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.server.reactive.RxNettyServerHttpRequest;
 import org.springframework.http.server.reactive.RxNettyServerHttpResponse;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.web.reactive.socket.HandshakeInfo;
 import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.WebSocketSession;
-import org.springframework.web.reactive.socket.HandshakeInfo;
 import org.springframework.web.reactive.socket.adapter.RxNettyWebSocketSession;
 import org.springframework.web.reactive.socket.server.RequestUpgradeStrategy;
 import org.springframework.web.server.ServerWebExchange;
@@ -46,13 +43,8 @@ public class RxNettyRequestUpgradeStrategy implements RequestUpgradeStrategy {
 	@Override
 	public Mono<Void> upgrade(ServerWebExchange exchange, WebSocketHandler handler) {
 
-		RxNettyServerHttpRequest request = (RxNettyServerHttpRequest) exchange.getRequest();
 		RxNettyServerHttpResponse response = (RxNettyServerHttpResponse) exchange.getResponse();
-
-		URI uri = request.getURI();
-		HttpHeaders headers = request.getHeaders();
-		Mono<Principal> principal = exchange.getPrincipal();
-		HandshakeInfo handshakeInfo = new HandshakeInfo(uri, headers, principal);
+		HandshakeInfo handshakeInfo = getHandshakeInfo(exchange);
 		NettyDataBufferFactory bufferFactory = (NettyDataBufferFactory) response.bufferFactory();
 
 		Observable<Void> completion = response.getRxNettyResponse()
@@ -65,6 +57,11 @@ public class RxNettyRequestUpgradeStrategy implements RequestUpgradeStrategy {
 		return Mono.from(RxReactiveStreams.toPublisher(completion));
 	}
 
+	private HandshakeInfo getHandshakeInfo(ServerWebExchange exchange) {
+		ServerHttpRequest request = exchange.getRequest();
+		return new HandshakeInfo(request.getURI(), request.getHeaders(), exchange.getPrincipal());
+	}
+
 	private static String[] getSubProtocols(WebSocketHandler webSocketHandler) {
 		List<String> subProtocols = webSocketHandler.getSubProtocols();
 		return subProtocols.toArray(new String[subProtocols.size()]);

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/upgrade/TomcatRequestUpgradeStrategy.java

@@ -17,8 +17,6 @@
 package org.springframework.web.reactive.socket.server.upgrade;
 
 import java.io.IOException;
-import java.net.URI;
-import java.security.Principal;
 import java.util.Collections;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
@@ -31,7 +29,6 @@ import org.apache.tomcat.websocket.server.WsServerContainer;
 import reactor.core.publisher.Mono;
 
 import org.springframework.core.io.buffer.DataBufferFactory;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.http.server.reactive.ServletServerHttpRequest;
@@ -39,7 +36,7 @@ import org.springframework.http.server.reactive.ServletServerHttpResponse;
 import org.springframework.util.Assert;
 import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.HandshakeInfo;
-import org.springframework.web.reactive.socket.adapter.TomcatWebSocketHandlerAdapter;
+import org.springframework.web.reactive.socket.adapter.StandardWebSocketHandlerAdapter;
 import org.springframework.web.reactive.socket.server.RequestUpgradeStrategy;
 import org.springframework.web.server.ServerWebExchange;
 
@@ -63,15 +60,13 @@ public class TomcatRequestUpgradeStrategy implements RequestUpgradeStrategy {
 		HttpServletRequest servletRequest = getHttpServletRequest(request);
 		HttpServletResponse servletResponse = getHttpServletResponse(response);
 
-		URI uri = request.getURI();
-		HttpHeaders headers = request.getHeaders();
-		Mono<Principal> principal = exchange.getPrincipal();
-		HandshakeInfo info = new HandshakeInfo(uri, headers, principal);
-		DataBufferFactory bufferFactory = response.bufferFactory();
-		Endpoint endpoint = new TomcatWebSocketHandlerAdapter(info, bufferFactory, handler).getEndpoint();
+		HandshakeInfo info = getHandshakeInfo(exchange);
+		DataBufferFactory factory = response.bufferFactory();
+		Endpoint endpoint = new StandardWebSocketHandlerAdapter(handler, info, factory).getEndpoint();
 
 		String requestURI = servletRequest.getRequestURI();
-		ServerEndpointConfig config = new ServerEndpointRegistration(requestURI, endpoint);
+		ServerEndpointConfig config = new DefaultServerEndpointConfig(requestURI, endpoint);
+
 		try {
 			WsServerContainer container = getContainer(servletRequest);
 			container.doUpgrade(servletRequest, servletResponse, config, Collections.emptyMap());
@@ -93,6 +88,11 @@ public class TomcatRequestUpgradeStrategy implements RequestUpgradeStrategy {
 		return ((ServletServerHttpResponse) response).getServletResponse();
 	}
 
+	private HandshakeInfo getHandshakeInfo(ServerWebExchange exchange) {
+		ServerHttpRequest request = exchange.getRequest();
+		return new HandshakeInfo(request.getURI(), request.getHeaders(), exchange.getPrincipal());
+	}
+
 	private WsServerContainer getContainer(HttpServletRequest request) {
 		ServletContext servletContext = request.getServletContext();
 		Object container = servletContext.getAttribute(SERVER_CONTAINER_ATTR);

spring-web-reactive/src/main/java/org/springframework/web/reactive/socket/server/upgrade/UndertowRequestUpgradeStrategy.java

@@ -16,26 +16,22 @@
 
 package org.springframework.web.reactive.socket.server.upgrade;
 
-import java.net.URI;
-import java.security.Principal;
+import io.undertow.server.HttpServerExchange;
+import io.undertow.websockets.WebSocketConnectionCallback;
+import io.undertow.websockets.WebSocketProtocolHandshakeHandler;
+import reactor.core.publisher.Mono;
 
 import org.springframework.core.io.buffer.DataBufferFactory;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.http.server.reactive.UndertowServerHttpRequest;
 import org.springframework.util.Assert;
-import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.HandshakeInfo;
+import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.adapter.UndertowWebSocketHandlerAdapter;
 import org.springframework.web.reactive.socket.server.RequestUpgradeStrategy;
 import org.springframework.web.server.ServerWebExchange;
 
-import io.undertow.server.HttpServerExchange;
-import io.undertow.websockets.WebSocketConnectionCallback;
-import io.undertow.websockets.WebSocketProtocolHandshakeHandler;
-import reactor.core.publisher.Mono;
-
 /**
 * A {@link RequestUpgradeStrategy} for use with Undertow.
   * 
@@ -51,18 +47,15 @@ public class UndertowRequestUpgradeStrategy implements RequestUpgradeStrategy {
 		ServerHttpRequest request = exchange.getRequest();
 		ServerHttpResponse response = exchange.getResponse();
 
-		URI uri = request.getURI();
-		HttpHeaders headers = request.getHeaders();
-		Mono<Principal> principal = exchange.getPrincipal();
-		HandshakeInfo info = new HandshakeInfo(uri, headers, principal);
+		HandshakeInfo info = getHandshakeInfo(exchange);
 		DataBufferFactory bufferFactory = response.bufferFactory();
 
-		WebSocketConnectionCallback callback =
-				new UndertowWebSocketHandlerAdapter(info, bufferFactory, handler);
-
 		Assert.isTrue(request instanceof UndertowServerHttpRequest);
 		HttpServerExchange httpExchange = ((UndertowServerHttpRequest) request).getUndertowExchange();
 
+		WebSocketConnectionCallback callback =
+				new UndertowWebSocketHandlerAdapter(handler, info, bufferFactory);
+
 		try {
 			new WebSocketProtocolHandshakeHandler(callback).handleRequest(httpExchange);
 		}
@@ -73,4 +66,9 @@ public class UndertowRequestUpgradeStrategy implements RequestUpgradeStrategy {
 		return Mono.empty();
 	}
 
+	private HandshakeInfo getHandshakeInfo(ServerWebExchange exchange) {
+		ServerHttpRequest request = exchange.getRequest();
+		return new HandshakeInfo(request.getURI(), request.getHeaders(), exchange.getPrincipal());
+	}
+
 }

spring-websocket/src/main/java/org/springframework/web/socket/server/standard/ServerEndpointRegistration.java

@@ -48,7 +48,7 @@ import org.springframework.web.socket.handler.BeanCreatingHandlerProvider;
  * override methods for customizing the handshake process.
  *
  * @author Rossen Stoyanchev
- * @since 4.0
+ * @since 5.0
  * @see ServerEndpointExporter
  */
 public class ServerEndpointRegistration extends ServerEndpointConfig.Configurator