Polish Stream#toList() consistent usage

In general, `Stream#toList()` is not a transparent replacement for
`.collect(Collectors.toList()))`, as the former returns an immutable
list.

This commit reverts some of those changes, where the returned `List`
instance was expected to be mutable.

See gh-29203

spring-core/src/main/java/org/springframework/util/MimeTypeUtils.java

@@ -29,6 +29,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Random;
 import java.util.function.BiPredicate;
+import java.util.stream.Collectors;
 
 import org.springframework.lang.Nullable;
 
@@ -279,7 +280,7 @@ public abstract class MimeTypeUtils {
 	}
 
 	/**
-	 * Parse the comma-separated string into a list of {@code MimeType} objects.
+	 * Parse the comma-separated string into a mutable list of {@code MimeType} objects.
 	 * @param mimeTypes the string to parse
 	 * @return the list of mime types
 	 * @throws InvalidMimeTypeException if the string cannot be parsed
@@ -291,7 +292,7 @@ public abstract class MimeTypeUtils {
 		return tokenize(mimeTypes).stream()
 				.filter(StringUtils::hasText)
 				.map(MimeTypeUtils::parseMimeType)
-				.toList();
+				.collect(Collectors.toList());
 	}
 
 	/**

spring-web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -25,6 +25,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import io.micrometer.observation.Observation;
@@ -970,7 +971,7 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 						.filter(converter -> canReadResponse(this.responseType, converter))
 						.flatMap((HttpMessageConverter<?> converter) -> getSupportedMediaTypes(this.responseType, converter))
 						.distinct()
-						.toList();
+						.collect(Collectors.toList());
 				MimeTypeUtils.sortBySpecificity(allSupportedMediaTypes);
 				if (logger.isDebugEnabled()) {
 					logger.debug("Accept=" + allSupportedMediaTypes);

spring-web/src/main/java/org/springframework/web/cors/CorsConfiguration.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.
@@ -25,6 +25,7 @@ import java.util.Objects;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import org.springframework.http.HttpMethod;
 import org.springframework.lang.Nullable;
@@ -135,7 +136,7 @@ public class CorsConfiguration {
 	 */
 	public void setAllowedOrigins(@Nullable List<String> origins) {
 		this.allowedOrigins = (origins == null ? null :
-				origins.stream().filter(Objects::nonNull).map(this::trimTrailingSlash).toList());
+				origins.stream().filter(Objects::nonNull).map(this::trimTrailingSlash).collect(Collectors.toList()));
 	}
 
 	private String trimTrailingSlash(String origin) {