Support for SSLContext configuration on StandardWebSocketClient

Closes gh-30680

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -114,7 +114,7 @@ public class StandardWebSocketClient implements WebSocketClient {
 						return Mono.error(ex);
 					}
 				})
-				.subscribeOn(Schedulers.boundedElastic()); // connectToServer is blocking
+				.subscribeOn(Schedulers.boundedElastic());  // connectToServer is blocking
 	}
 
 	private StandardWebSocketHandlerAdapter createEndpoint(URI url, WebSocketHandler handler,
@@ -130,24 +130,38 @@ public class StandardWebSocketClient implements WebSocketClient {
 		return new HandshakeInfo(url, responseHeaders, Mono.empty(), protocol);
 	}
 
+	/**
+	 * Create the {@link StandardWebSocketSession} for the given Jakarta WebSocket Session.
+	 * @see #bufferFactory()
+	 */
 	protected StandardWebSocketSession createWebSocketSession(
 			Session session, HandshakeInfo info, Sinks.Empty<Void> completionSink) {
 
-		return new StandardWebSocketSession(
-				session, info, DefaultDataBufferFactory.sharedInstance, completionSink);
+		return new StandardWebSocketSession(session, info, bufferFactory(), completionSink);
 	}
 
-	private ClientEndpointConfig createEndpointConfig(Configurator configurator, List<String> subProtocols) {
+	/**
+	 * Return the {@link DataBufferFactory} to use.
+	 * @see #createWebSocketSession
+	 */
+	protected DataBufferFactory bufferFactory() {
+		return DefaultDataBufferFactory.sharedInstance;
+	}
+
+	/**
+	 * Create the {@link ClientEndpointConfig} for the given configurator.
+	 * Can be overridden to add extensions or an SSL context.
+	 * @param configurator the configurator to apply
+	 * @param subProtocols the preferred sub-protocols
+	 * @since 6.1.3
+	 */
+	protected ClientEndpointConfig createEndpointConfig(Configurator configurator, List<String> subProtocols) {
 		return ClientEndpointConfig.Builder.create()
 				.configurator(configurator)
 				.preferredSubprotocols(subProtocols)
 				.build();
 	}
 
-	protected DataBufferFactory bufferFactory() {
-		return DefaultDataBufferFactory.sharedInstance;
-	}
-
 
 	private static final class DefaultConfigurator extends Configurator {
 

spring-websocket/src/main/java/org/springframework/web/socket/client/standard/StandardWebSocketClient.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -28,6 +28,8 @@ import java.util.Map;
 import java.util.concurrent.Callable;
 import java.util.concurrent.CompletableFuture;
 
+import javax.net.ssl.SSLContext;
+
 import jakarta.websocket.ClientEndpointConfig;
 import jakarta.websocket.ClientEndpointConfig.Configurator;
 import jakarta.websocket.ContainerProvider;
@@ -54,6 +56,7 @@ import org.springframework.web.socket.client.AbstractWebSocketClient;
  * A WebSocketClient based on the standard Jakarta WebSocket API.
  *
  * @author Rossen Stoyanchev
+ * @author Juergen Hoeller
  * @since 4.0
  */
 public class StandardWebSocketClient extends AbstractWebSocketClient {
@@ -62,6 +65,9 @@ public class StandardWebSocketClient extends AbstractWebSocketClient {
 
 	private final Map<String,Object> userProperties = new HashMap<>();
 
+	@Nullable
+	private SSLContext sslContext;
+
 	@Nullable
 	private AsyncTaskExecutor taskExecutor = new SimpleAsyncTaskExecutor();
 
@@ -100,12 +106,29 @@ public class StandardWebSocketClient extends AbstractWebSocketClient {
 	}
 
 	/**
-	 * The configured user properties.
+	 * Return the configured user properties.
 	 */
 	public Map<String, Object> getUserProperties() {
 		return this.userProperties;
 	}
 
+	/**
+	 * Set the {@link SSLContext} to use for {@link ClientEndpointConfig#getSSLContext()}.
+	 * @since 6.1.3
+	 */
+	public void setSslContext(@Nullable SSLContext sslContext) {
+		this.sslContext = sslContext;
+	}
+
+	/**
+	 * Return the {@link SSLContext} to use.
+	 * @since 6.1.3
+	 */
+	@Nullable
+	public SSLContext getSslContext() {
+		return this.sslContext;
+	}
+
 	/**
 	 * Set an {@link AsyncTaskExecutor} to use when opening connections.
 	 * <p>If this property is set to {@code null}, calls to any of the
@@ -134,17 +157,19 @@ public class StandardWebSocketClient extends AbstractWebSocketClient {
 		InetSocketAddress localAddress = new InetSocketAddress(getLocalHost(), port);
 		InetSocketAddress remoteAddress = new InetSocketAddress(uri.getHost(), port);
 
-		final StandardWebSocketSession session = new StandardWebSocketSession(headers,
+		StandardWebSocketSession session = new StandardWebSocketSession(headers,
 				attributes, localAddress, remoteAddress);
 
-		final ClientEndpointConfig endpointConfig = ClientEndpointConfig.Builder.create()
+		ClientEndpointConfig endpointConfig = ClientEndpointConfig.Builder.create()
 				.configurator(new StandardWebSocketClientConfigurator(headers))
 				.preferredSubprotocols(protocols)
-				.extensions(adaptExtensions(extensions)).build();
+				.extensions(adaptExtensions(extensions))
+				.sslContext(getSslContext())
+				.build();
 
 		endpointConfig.getUserProperties().putAll(getUserProperties());
 
-		final Endpoint endpoint = new StandardWebSocketHandlerAdapter(webSocketHandler, session);
+		Endpoint endpoint = new StandardWebSocketHandlerAdapter(webSocketHandler, session);
 
 		Callable<WebSocketSession> connectTask = () -> {
 			this.webSocketContainer.connectToServer(endpoint, endpointConfig, uri);
@@ -167,7 +192,7 @@ public class StandardWebSocketClient extends AbstractWebSocketClient {
 		return result;
 	}
 
-	private InetAddress getLocalHost() {
+	private static InetAddress getLocalHost() {
 		try {
 			return InetAddress.getLocalHost();
 		}
@@ -176,7 +201,7 @@ public class StandardWebSocketClient extends AbstractWebSocketClient {
 		}
 	}
 
-	private int getPort(URI uri) {
+	private static int getPort(URI uri) {
 		if (uri.getPort() == -1) {
 			String scheme = uri.getScheme().toLowerCase(Locale.ENGLISH);
 			return ("wss".equals(scheme) ? 443 : 80);