Polishing and minor refactoring

See gh-25884

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/ErrorsMethodArgumentResolver.java

@@ -57,9 +57,10 @@ public class ErrorsMethodArgumentResolver extends HandlerMethodArgumentResolverS
 
 		Object errors = getErrors(parameter, context);
 
-		// Initially Errors/BindingResult is a Mono in the model even if it cannot be declared
-		// as an async argument. That way it can be resolved first while the Mono can complete
-		// later at which point the model is also updated for further use.
+		// Initially ModelAttributeMethodArgumentResolver adds Errors/BindingResult as a
+		// Mono in the model even if it can't be declared as such on a controller method.
+		// This is done to enable early argument resolution here. When the Mono actually
+		// completes it is replaced in the model with the actual value.
 
 		if (Mono.class.isAssignableFrom(errors.getClass())) {
 			return ((Mono<?>) errors).cast(Object.class);

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/ModelAttributeMethodArgumentResolver.java

@@ -119,13 +119,13 @@ public class ModelAttributeMethodArgumentResolver extends HandlerMethodArgumentR
 		return valueMono.flatMap(value -> {
 			WebExchangeDataBinder binder = context.createDataBinder(exchange, value, name);
 			return bindRequestParameters(binder, exchange)
-					.doOnError(ex -> bindingResultSink.emitError(ex, Sinks.EmitFailureHandler.FAIL_FAST))
+					.doOnError(bindingResultSink::tryEmitError)
 					.doOnSuccess(aVoid -> {
 						validateIfApplicable(binder, parameter);
 						BindingResult bindingResult = binder.getBindingResult();
 						model.put(BindingResult.MODEL_KEY_PREFIX + name, bindingResult);
 						model.put(name, value);
-						// serialized and buffered (should never fail)
+						// Ignore result: serialized and buffered (should never fail)
 						bindingResultSink.tryEmitValue(bindingResult);
 					})
 					.then(Mono.fromCallable(() -> {

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

@@ -21,6 +21,7 @@ import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
 import javax.websocket.Session;
 
 import org.apache.tomcat.websocket.WsSession;
+import reactor.core.publisher.Sinks;
 
 import org.springframework.core.io.buffer.DataBufferFactory;
 import org.springframework.web.reactive.socket.HandshakeInfo;
@@ -46,7 +47,14 @@ public class TomcatWebSocketSession extends StandardWebSocketSession {
 		super(session, info, factory);
 	}
 
-	@SuppressWarnings("deprecation")
+	public TomcatWebSocketSession(Session session, HandshakeInfo info, DataBufferFactory factory,
+			Sinks.Empty<Void> completionSink) {
+
+		super(session, info, factory, completionSink);
+		suspendReceiving();
+	}
+
+	@Deprecated
 	public TomcatWebSocketSession(Session session, HandshakeInfo info, DataBufferFactory factory,
 			reactor.core.publisher.MonoProcessor<Void> completionMono) {
 

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

@@ -112,10 +112,10 @@ public class StandardWebSocketClient implements WebSocketClient {
 	}
 
 	private StandardWebSocketHandlerAdapter createEndpoint(URI url, WebSocketHandler handler,
-			Sinks.Empty<Void> completion, DefaultConfigurator configurator) {
+			Sinks.Empty<Void> completionSink, DefaultConfigurator configurator) {
 
 		return new StandardWebSocketHandlerAdapter(handler, session ->
-				createWebSocketSession(session, createHandshakeInfo(url, configurator), completion));
+				createWebSocketSession(session, createHandshakeInfo(url, configurator), completionSink));
 	}
 
 	private HandshakeInfo createHandshakeInfo(URI url, DefaultConfigurator configurator) {
@@ -124,21 +124,13 @@ public class StandardWebSocketClient implements WebSocketClient {
 		return new HandshakeInfo(url, responseHeaders, Mono.empty(), protocol);
 	}
 
-	protected StandardWebSocketSession createWebSocketSession(Session session, HandshakeInfo info,
-			Sinks.Empty<Void> completionSink) {
+	protected StandardWebSocketSession createWebSocketSession(
+			Session session, HandshakeInfo info, Sinks.Empty<Void> completionSink) {
 
 		return new StandardWebSocketSession(
 				session, info, DefaultDataBufferFactory.sharedInstance, completionSink);
 	}
 
-	@Deprecated
-	protected StandardWebSocketSession createWebSocketSession(Session session, HandshakeInfo info,
-			reactor.core.publisher.MonoProcessor<Void> completionMono) {
-
-		return new StandardWebSocketSession(
-				session, info, DefaultDataBufferFactory.sharedInstance, completionMono);
-	}
-
 	private ClientEndpointConfig createEndpointConfig(Configurator configurator, List<String> subProtocols) {
 		return ClientEndpointConfig.Builder.create()
 				.configurator(configurator)

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -20,6 +20,7 @@ import javax.websocket.Session;
 import javax.websocket.WebSocketContainer;
 
 import org.apache.tomcat.websocket.WsWebSocketContainer;
+import reactor.core.publisher.Sinks;
 
 import org.springframework.web.reactive.socket.HandshakeInfo;
 import org.springframework.web.reactive.socket.adapter.StandardWebSocketSession;
@@ -44,11 +45,10 @@ public class TomcatWebSocketClient extends StandardWebSocketClient {
 
 
 	@Override
-	@SuppressWarnings("deprecation")
-	protected StandardWebSocketSession createWebSocketSession(Session session,
-			HandshakeInfo info, reactor.core.publisher.MonoProcessor<Void> completionMono) {
+	protected StandardWebSocketSession createWebSocketSession(
+			Session session, HandshakeInfo info, Sinks.Empty<Void> completionSink) {
 
-			return new TomcatWebSocketSession(session, info, bufferFactory(), completionMono);
+		return new TomcatWebSocketSession(session, info, bufferFactory(), completionSink);
 	}
 
 }