Add PreFlightRequestFilter

Closes gh-36482

spring-web/src/main/java/org/springframework/web/filter/PreFlightRequestFilter.java

@@ -0,0 +1,71 @@
+/*
+ * 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.filter;
+
+import java.io.IOException;
+
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+
+import org.springframework.util.Assert;
+import org.springframework.web.cors.CorsUtils;
+import org.springframework.web.cors.PreFlightRequestHandler;
+
+/**
+ * Servlet Filter that handles pre-flight requests through a
+ * {@link PreFlightRequestHandler} and bypasses the rest of the chain.
+ *
+ * <p>The {@code @EnableWebMvc} config declares bean of type
+ * {@code PreFlightRequestHandler}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 7.0.7
+ */
+public class PreFlightRequestFilter extends OncePerRequestFilter {
+
+	private final PreFlightRequestHandler handler;
+
+
+	public PreFlightRequestFilter(PreFlightRequestHandler handler) {
+		Assert.notNull(handler, "PreFlightRequestHandler is required");
+		this.handler = handler;
+	}
+
+
+	@Override
+	protected void doFilterInternal(
+			HttpServletRequest request, HttpServletResponse response, FilterChain chain)
+			throws ServletException, IOException {
+
+		if (!CorsUtils.isPreFlightRequest(request)) {
+			chain.doFilter(request, response);
+			return;
+		}
+
+		try {
+			this.handler.handlePreFlight(request, response);
+		}
+		catch (ServletException | IOException ex) {
+			throw ex;
+		}
+		catch (Throwable ex) {
+			throw new ServletException("Pre-flight request handling failed: " + ex, ex);
+		}
+	}
+}