Support API versioning via MediaType parameter

Closes gh-35050

spring-web/src/main/java/org/springframework/web/accept/MediaTypeParamApiVersionResolver.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2002-present 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.accept;
+
+import java.util.Enumeration;
+
+import jakarta.servlet.http.HttpServletRequest;
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+
+/**
+ * {@link ApiVersionResolver} that extracts the version from a media type
+ * parameter found in the Accept or Content-Type headers.
+ *
+ * @author Rossen Stoyanchev
+ * @since 7.0
+ */
+public class MediaTypeParamApiVersionResolver implements ApiVersionResolver {
+
+	private final MediaType compatibleMediaType;
+
+	private final String parameterName;
+
+
+	/**
+	 * Create an instance.
+	 * @param compatibleMediaType the media type to extract the parameter from with
+	 * the match established via {@link MediaType#isCompatibleWith(MediaType)}
+	 * @param paramName the name of the parameter
+	 */
+	public MediaTypeParamApiVersionResolver(MediaType compatibleMediaType, String paramName) {
+		this.compatibleMediaType = compatibleMediaType;
+		this.parameterName = paramName;
+	}
+
+
+	@Override
+	public @Nullable String resolveVersion(HttpServletRequest request) {
+		Enumeration<String> headers = request.getHeaders(HttpHeaders.ACCEPT);
+		while (headers.hasMoreElements()) {
+			String header = headers.nextElement();
+			for (MediaType mediaType : MediaType.parseMediaTypes(header)) {
+				if (this.compatibleMediaType.isCompatibleWith(mediaType)) {
+					return mediaType.getParameter(this.parameterName);
+				}
+			}
+		}
+		String header = request.getHeader(HttpHeaders.CONTENT_TYPE);
+		for (MediaType mediaType : MediaType.parseMediaTypes(header)) {
+			if (this.compatibleMediaType.isCompatibleWith(mediaType)) {
+				return mediaType.getParameter(this.parameterName);
+			}
+		}
+		return null;
+	}
+
+}