Revise contribution

This commit reverts changes to AbstractCacheManager since iterating
over the caches in a for-loop and a stream is duplicated effort.

This commit reverts changes to DefaultRenderingResponseBuilder,
RouterFunctions, and OriginHandshakeInterceptor since order matters for
those use cases: they were originally based on the semantics of
LinkedHashSet or LinkedHashMap; whereas, Set.copyOf() and Map.copyOf()
do not provide any guarantees regarding ordering.

This commit also applies analogous changes to "sibling" implementations
across Servlet mocks as well as Web MVC and WebFlux.

See gh-29321

spring-context/src/main/java/org/springframework/cache/support/AbstractCacheManager.java

@@ -22,7 +22,6 @@ import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
-import java.util.stream.Collectors;
 
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.cache.Cache;
@@ -65,13 +64,13 @@ public abstract class AbstractCacheManager implements CacheManager, Initializing
 		synchronized (this.cacheMap) {
 			this.cacheNames = Collections.emptySet();
 			this.cacheMap.clear();
+			Set<String> cacheNames = new LinkedHashSet<>(caches.size());
 			for (Cache cache : caches) {
 				String name = cache.getName();
 				this.cacheMap.put(name, decorateCache(cache));
+				cacheNames.add(name);
 			}
-			this.cacheNames = caches.stream()
-					.map(Cache::getName)
-					.collect(Collectors.toUnmodifiableSet());
+			this.cacheNames = Collections.unmodifiableSet(cacheNames);
 		}
 	}
 

spring-context/src/main/java/org/springframework/format/datetime/DateFormatter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.