Polishing contribution

Closes gh-26674

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

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -22,14 +22,14 @@ import java.security.Principal;
 import java.util.Collections;
 import java.util.Map;
 
-import org.springframework.http.HttpCookie;
-import org.springframework.util.CollectionUtils;
-import org.springframework.util.MultiValueMap;
 import reactor.core.publisher.Mono;
 
+import org.springframework.http.HttpCookie;
 import org.springframework.http.HttpHeaders;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
+import org.springframework.util.MultiValueMap;
 
 /**
  * Simple container of information related to the handshake request that started
@@ -41,6 +41,10 @@ import org.springframework.util.Assert;
  */
 public class HandshakeInfo {
 
+	private static final MultiValueMap<String, HttpCookie> EMPTY_COOKIES =
+			CollectionUtils.toMultiValueMap(Collections.emptyMap());
+
+
 	private final URI uri;
 
 	private final Mono<Principal> principalMono;
@@ -69,51 +73,51 @@ public class HandshakeInfo {
 	 * @param protocol the negotiated sub-protocol (may be {@code null})
 	 */
 	public HandshakeInfo(URI uri, HttpHeaders headers, Mono<Principal> principal, @Nullable String protocol) {
-		this(uri, headers, principal, protocol, null, Collections.emptyMap(), null);
+		this(uri, headers, EMPTY_COOKIES, principal, protocol, null, Collections.emptyMap(), null);
 	}
 
-
 	/**
-	 * Constructor targetting server-side use with extra information about the
-	 * handshake, the remote address, and a pre-existing log prefix for
-	 * correlation.
+	 * Constructor targeting server-side use with extra information such as the
+	 * the remote address, attributes, and a log prefix.
 	 * @param uri the endpoint URL
-	 * @param headers request headers for server or response headers or client
+	 * @param headers server request headers
 	 * @param principal the principal for the session
 	 * @param protocol the negotiated sub-protocol (may be {@code null})
-	 * @param remoteAddress the remote address where the handshake came from
-	 * @param attributes initial attributes to use for the WebSocket session
-	 * @param logPrefix log prefix used during the handshake for correlating log
-	 * messages, if any.
+	 * @param remoteAddress the remote address of the client
+	 * @param attributes initial attributes for the WebSocket session
+	 * @param logPrefix the log prefix for the handshake request.
 	 * @since 5.1
+	 * @deprecated as of 5.3.5 in favor of
+	 * {@link #HandshakeInfo(URI, HttpHeaders, MultiValueMap, Mono, String, InetSocketAddress, Map, String)}
 	 */
 	@Deprecated
 	public HandshakeInfo(URI uri, HttpHeaders headers, Mono<Principal> principal,
 				@Nullable String protocol, @Nullable InetSocketAddress remoteAddress,
 				Map<String, Object> attributes, @Nullable String logPrefix) {
-		this(uri, headers, CollectionUtils.toMultiValueMap(Collections.emptyMap()), principal, protocol, remoteAddress, attributes, logPrefix);
+
+		this(uri, headers, EMPTY_COOKIES, principal, protocol, remoteAddress, attributes, logPrefix);
 	}
 
 	/**
-	 * Constructor targetting server-side use with extra information about the
-	 * handshake, the remote address, and a pre-existing log prefix for
-	 * correlation.
+	 * Constructor targeting server-side use with extra information such as the
+	 * cookies, remote address, attributes, and a log prefix.
 	 * @param uri the endpoint URL
-	 * @param headers request headers for server or response headers or client
-	 * @param cookies request cookies for server
+	 * @param headers server request headers
+	 * @param cookies server request cookies
 	 * @param principal the principal for the session
 	 * @param protocol the negotiated sub-protocol (may be {@code null})
-	 * @param remoteAddress the remote address where the handshake came from
-	 * @param attributes initial attributes to use for the WebSocket session
-	 * @param logPrefix log prefix used during the handshake for correlating log
-	 * messages, if any.
-	 * @since 5.4
+	 * @param remoteAddress the remote address of the client
+	 * @param attributes initial attributes for the WebSocket session
+	 * @param logPrefix the log prefix for the handshake request.
+	 * @since 5.3.5
 	 */
 	public HandshakeInfo(URI uri, HttpHeaders headers, MultiValueMap<String, HttpCookie> cookies,
 				Mono<Principal> principal, @Nullable String protocol, @Nullable InetSocketAddress remoteAddress,
 				Map<String, Object> attributes, @Nullable String logPrefix) {
+
 		Assert.notNull(uri, "URI is required");
 		Assert.notNull(headers, "HttpHeaders are required");
+		Assert.notNull(cookies, "`cookies` are required");
 		Assert.notNull(principal, "Principal is required");
 		Assert.notNull(attributes, "'attributes' is required");
 
@@ -136,22 +140,25 @@ public class HandshakeInfo {
 	}
 
 	/**
-	 * Return the handshake HTTP headers. Those are the request headers for a
-	 * server session and the response headers for a client session.
+	 * Return the HTTP headers from the handshake request, either server request
+	 * headers for a server session or the client response headers for a client
+	 * session.
 	 */
 	public HttpHeaders getHeaders() {
 		return this.headers;
 	}
 
 	/**
-	 * Return the handshake HTTP cookies.
+	 * For a server session this returns the server request cookies from the
+	 * handshake request. For a client session, it is an empty map.
+	 * @since 5.3.5
 	 */
 	public MultiValueMap<String, HttpCookie> getCookies() {
 		return this.cookies;
 	}
 
 	/**
-	 * Return the principal associated with the handshake HTTP request.
+	 * Return the principal associated with the handshake request, if any.
 	 */
 	public Mono<Principal> getPrincipal() {
 		return this.principalMono;
@@ -168,8 +175,8 @@ public class HandshakeInfo {
 	}
 
 	/**
-	 * For a server-side session this is the remote address where the handshake
-	 * request came from.
+	 * For a server session this is the remote address where the handshake
+	 * request came from. For a client session, it is {@code null}.
 	 * @since 5.1
 	 */
 	@Nullable
@@ -178,8 +185,7 @@ public class HandshakeInfo {
 	}
 
 	/**
-	 * Attributes extracted from the handshake request to be added to the
-	 * WebSocket session.
+	 * Attributes extracted from the handshake request to add to the session.
 	 * @since 5.1
 	 */
 	public Map<String, Object> getAttributes() {
@@ -199,7 +205,7 @@ public class HandshakeInfo {
 
 	@Override
 	public String toString() {
-		return "HandshakeInfo[uri=" + this.uri + ", headers=" + this.headers + "]";
+		return "HandshakeInfo[uri=" + this.uri + "]";
 	}
 
 }

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

@@ -30,17 +30,16 @@ import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Mono;
 
 import org.springframework.context.Lifecycle;
+import org.springframework.http.HttpCookie;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
-import org.springframework.http.HttpCookie;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.MultiValueMap;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
-import org.springframework.util.MultiValueMap;
-import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.web.reactive.socket.HandshakeInfo;
 import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.server.RequestUpgradeStrategy;
@@ -285,8 +284,7 @@ public class HandshakeWebSocketService implements WebSocketService, Lifecycle {
 		// the server implementation once the handshake HTTP exchange is done.
 		HttpHeaders headers = new HttpHeaders();
 		headers.addAll(request.getHeaders());
-		MultiValueMap<String, HttpCookie> cookies = new LinkedMultiValueMap<>();
-		cookies.addAll(request.getCookies());
+		MultiValueMap<String, HttpCookie> cookies = request.getCookies();
 		Mono<Principal> principal = exchange.getPrincipal();
 		String logPrefix = exchange.getLogPrefix();
 		InetSocketAddress remoteAddress = request.getRemoteAddress();