diff --git a/spring-web/src/main/java/org/springframework/http/client/reactive/Netty5HeadersAdapter.java b/spring-web/src/main/java/org/springframework/http/client/reactive/Netty5HeadersAdapter.java
index 84784301b8..7bf25d2cfd 100644
--- a/spring-web/src/main/java/org/springframework/http/client/reactive/Netty5HeadersAdapter.java
+++ b/spring-web/src/main/java/org/springframework/http/client/reactive/Netty5HeadersAdapter.java
@@ -19,12 +19,11 @@ package org.springframework.http.client.reactive;
 import java.util.AbstractSet;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.Spliterator;
-import java.util.Spliterators;
 import java.util.stream.StreamSupport;
 
 import io.netty5.handler.codec.http.headers.HttpHeaders;
@@ -38,7 +37,7 @@ import org.springframework.util.MultiValueMap;
  *
  * <p>There is a duplicate of this class in the server package!
  *
- * This class is based on {@link NettyHeadersAdapter}.
+ * <p>This class is based on {@link NettyHeadersAdapter}.
  *
  * @author Violeta Georgieva
  * @since 6.0
@@ -57,7 +56,7 @@ class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	@Nullable
 	public String getFirst(String key) {
 		CharSequence value = this.headers.get(key);
-		return value != null ? value.toString() : null;
+		return (value != null ? value.toString() : null);
 	}
 
 	@Override
@@ -117,17 +116,19 @@ class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 
 	@Override
 	public boolean containsValue(Object value) {
-		return (value instanceof String &&
-				StreamSupport.stream(
-								Spliterators.spliteratorUnknownSize(this.headers.iterator(), Spliterator.ORDERED), false)
+		return (value instanceof CharSequence &&
+				StreamSupport.stream(this.headers.spliterator(), false)
 						.anyMatch(entry -> value.equals(entry.getValue())));
 	}
 
 	@Override
 	@Nullable
 	public List<String> get(Object key) {
-		if (containsKey(key)) {
-			return getAll(this.headers.valuesIterator((CharSequence) key));
+		Iterator<CharSequence> iterator = this.headers.valuesIterator((CharSequence) key);
+		if (iterator.hasNext()) {
+			List<String> result = new ArrayList<>();
+			iterator.forEachRemaining(value -> result.add(value.toString()));
+			return result;
 		}
 		return null;
 	}
@@ -135,7 +136,7 @@ class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	@Nullable
 	@Override
 	public List<String> put(String key, @Nullable List<String> value) {
-		List<String> previousValues = getAll(this.headers.valuesIterator(key));
+		List<String> previousValues = get(key);
 		this.headers.set(key, value);
 		return previousValues;
 	}
@@ -144,7 +145,7 @@ class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	@Override
 	public List<String> remove(Object key) {
 		if (key instanceof String headerName) {
-			List<String> previousValues = getAll(this.headers.valuesIterator(headerName));
+			List<String> previousValues = get(headerName);
 			this.headers.remove(headerName);
 			return previousValues;
 		}
@@ -168,8 +169,9 @@ class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 
 	@Override
 	public Collection<List<String>> values() {
-		return this.headers.names().stream()
-				.map(key -> getAll(this.headers.valuesIterator(key))).toList();
+		List<List<String>> result = new ArrayList<>(this.headers.size());
+		forEach((key, value) -> result.add(value));
+		return result;
 	}
 
 	@Override
@@ -194,19 +196,6 @@ class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	}
 
 
-	@Nullable
-	private static List<String> getAll(Iterator<CharSequence> valuesIterator) {
-		if (!valuesIterator.hasNext()) {
-			return null;
-		}
-		List<String> result = new ArrayList<>();
-		while (valuesIterator.hasNext()) {
-			result.add(valuesIterator.next().toString());
-		}
-		return result;
-	}
-
-
 	private class EntryIterator implements Iterator<Entry<String, List<String>>> {
 
 		private final Iterator<CharSequence> names = headers.names().iterator();
@@ -238,12 +227,8 @@ class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 
 		@Override
 		public List<String> getValue() {
-			List<String> result = new ArrayList<>();
-			Iterator<CharSequence> valuesIterator = headers.valuesIterator(this.key);
-			while (valuesIterator.hasNext()) {
-				result.add(valuesIterator.next().toString());
-			}
-			return result;
+			List<String> values = get(this.key);
+			return (values != null ? values : Collections.emptyList());
 		}
 
 		@Override
diff --git a/spring-web/src/main/java/org/springframework/http/server/reactive/Netty5HeadersAdapter.java b/spring-web/src/main/java/org/springframework/http/server/reactive/Netty5HeadersAdapter.java
index 1d5fc7d610..35714334a1 100644
--- a/spring-web/src/main/java/org/springframework/http/server/reactive/Netty5HeadersAdapter.java
+++ b/spring-web/src/main/java/org/springframework/http/server/reactive/Netty5HeadersAdapter.java
@@ -19,12 +19,11 @@ package org.springframework.http.server.reactive;
 import java.util.AbstractSet;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.Spliterator;
-import java.util.Spliterators;
 import java.util.stream.StreamSupport;
 
 import io.netty5.handler.codec.http.headers.HttpHeaders;
@@ -55,7 +54,7 @@ final class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	@Nullable
 	public String getFirst(String key) {
 		CharSequence value = this.headers.get(key);
-		return value != null ? value.toString() : null;
+		return (value != null ? value.toString() : null);
 	}
 
 	@Override
@@ -116,16 +115,18 @@ final class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	@Override
 	public boolean containsValue(Object value) {
 		return (value instanceof String &&
-				StreamSupport.stream(
-								Spliterators.spliteratorUnknownSize(this.headers.iterator(), Spliterator.ORDERED), false)
+				StreamSupport.stream(this.headers.spliterator(), false)
 						.anyMatch(entry -> value.equals(entry.getValue())));
 	}
 
 	@Override
 	@Nullable
 	public List<String> get(Object key) {
-		if (containsKey(key)) {
-			return getAll(this.headers.valuesIterator((CharSequence) key));
+		Iterator<CharSequence> iterator = this.headers.valuesIterator((CharSequence) key);
+		if (iterator.hasNext()) {
+			List<String> result = new ArrayList<>();
+			iterator.forEachRemaining(value -> result.add(value.toString()));
+			return result;
 		}
 		return null;
 	}
@@ -133,7 +134,7 @@ final class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	@Nullable
 	@Override
 	public List<String> put(String key, @Nullable List<String> value) {
-		List<String> previousValues = getAll(this.headers.valuesIterator(key));
+		List<String> previousValues = get(key);
 		this.headers.set(key, value);
 		return previousValues;
 	}
@@ -142,7 +143,7 @@ final class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	@Override
 	public List<String> remove(Object key) {
 		if (key instanceof String headerName) {
-			List<String> previousValues = getAll(this.headers.valuesIterator(headerName));
+			List<String> previousValues = get(headerName);
 			this.headers.remove(headerName);
 			return previousValues;
 		}
@@ -166,8 +167,9 @@ final class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 
 	@Override
 	public Collection<List<String>> values() {
-		return this.headers.names().stream()
-				.map(key -> getAll(this.headers.valuesIterator(key))).toList();
+		List<List<String>> result = new ArrayList<>(this.headers.size());
+		forEach((key, value) -> result.add(value));
+		return result;
 	}
 
 	@Override
@@ -192,19 +194,6 @@ final class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 	}
 
 
-	@Nullable
-	private static List<String> getAll(Iterator<CharSequence> valuesIterator) {
-		if (!valuesIterator.hasNext()) {
-			return null;
-		}
-		List<String> result = new ArrayList<>();
-		while (valuesIterator.hasNext()) {
-			result.add(valuesIterator.next().toString());
-		}
-		return result;
-	}
-
-
 	private class EntryIterator implements Iterator<Entry<String, List<String>>> {
 
 		private final Iterator<CharSequence> names = headers.names().iterator();
@@ -236,12 +225,8 @@ final class Netty5HeadersAdapter implements MultiValueMap<String, String> {
 
 		@Override
 		public List<String> getValue() {
-			List<String> result = new ArrayList<>();
-			Iterator<CharSequence> valuesIterator = headers.valuesIterator(this.key);
-			while (valuesIterator.hasNext()) {
-				result.add(valuesIterator.next().toString());
-			}
-			return result;
+			List<String> values = get(this.key);
+			return (values != null ? values : Collections.emptyList());
 		}
 
 		@Override
diff --git a/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorNetty2ServerHttpRequest.java b/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorNetty2ServerHttpRequest.java
index 7f64333050..67b8fa02e4 100644
--- a/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorNetty2ServerHttpRequest.java
+++ b/spring-web/src/main/java/org/springframework/http/server/reactive/ReactorNetty2ServerHttpRequest.java
@@ -80,9 +80,9 @@ class ReactorNetty2ServerHttpRequest extends AbstractServerHttpRequest {
 
 	private static URI resolveBaseUrl(HttpServerRequest request) throws URISyntaxException {
 		String scheme = getScheme(request);
-		CharSequence headerCS = request.requestHeaders().get(HttpHeaderNames.HOST);
-		if (headerCS != null) {
-			String header = headerCS.toString();
+		CharSequence charSequence = request.requestHeaders().get(HttpHeaderNames.HOST);
+		if (charSequence != null) {
+			String header = charSequence.toString();
 			final int portIndex;
 			if (header.startsWith("[")) {
 				portIndex = header.indexOf(':', header.indexOf(']'));
diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/client/ReactorNetty2WebSocketClient.java b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/client/ReactorNetty2WebSocketClient.java
index 0db51916d9..beaf75a392 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/client/ReactorNetty2WebSocketClient.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/client/ReactorNetty2WebSocketClient.java
@@ -157,11 +157,8 @@ public class ReactorNetty2WebSocketClient implements WebSocketClient {
 
 	private HttpHeaders toHttpHeaders(WebsocketInbound inbound) {
 		HttpHeaders headers = new HttpHeaders();
-		io.netty5.handler.codec.http.headers.HttpHeaders nettyHeaders = inbound.headers();
-		nettyHeaders.forEach(entry -> {
-			CharSequence name = entry.getKey();
-			headers.put(name.toString(), getAll(nettyHeaders.valuesIterator(name)));
-		});
+		inbound.headers().iterator().forEachRemaining(entry ->
+				headers.add(entry.getKey().toString(), entry.getValue().toString()));
 		return headers;
 	}