Add getHandler in reactive AbstractHandlerMapping

Author: rstoyanchev

spring-web-reactive/src/main/java/org/springframework/web/reactive/config/WebReactiveConfiguration.java

@@ -469,7 +469,7 @@ protected void configureViewResolvers(ViewResolverRegistry registry) {
 	private static final class EmptyHandlerMapping extends AbstractHandlerMapping {
 
 		@Override
-		public Mono<Object> getHandler(ServerWebExchange exchange) {
+		public Mono<Object> getHandlerInternal(ServerWebExchange exchange) {
 			return Mono.empty();
 		}
 	}

spring-web-reactive/src/main/java/org/springframework/web/reactive/handler/AbstractHandlerMapping.java

@@ -150,20 +150,38 @@ public CorsProcessor getCorsProcessor() {
 	}
 
 
-	protected Object processCorsRequest(ServerWebExchange exchange, Object handler) {
-		if (CorsUtils.isCorsRequest(exchange.getRequest())) {
-			CorsConfiguration configA = this.globalCorsConfigSource.getCorsConfiguration(exchange);
-			CorsConfiguration configB = getCorsConfiguration(handler, exchange);
-			CorsConfiguration config = (configA != null ? configA.combine(configB) : configB);
-
-			if (!getCorsProcessor().processRequest(config, exchange) ||
-					CorsUtils.isPreFlightRequest(exchange.getRequest())) {
-				return REQUEST_HANDLED_HANDLER;
+	@Override
+	public Mono<Object> getHandler(ServerWebExchange exchange) {
+		return getHandlerInternal(exchange).map(handler -> {
+			if (CorsUtils.isCorsRequest(exchange.getRequest())) {
+				CorsConfiguration configA = this.globalCorsConfigSource.getCorsConfiguration(exchange);
+				CorsConfiguration configB = getCorsConfiguration(handler, exchange);
+				CorsConfiguration config = (configA != null ? configA.combine(configB) : configB);
+
+				if (!getCorsProcessor().processRequest(config, exchange) ||
+						CorsUtils.isPreFlightRequest(exchange.getRequest())) {
+					return REQUEST_HANDLED_HANDLER;
+				}
 			}
-		}
-		return handler;
+			return handler;
+		});
 	}
 
+	/**
+	 * Look up a handler for the given request, returning an empty {@code Mono}
+	 * if no specific one is found. This method is called by {@link #getHandler}.
+	 *
+	 * <p>On CORS pre-flight requests this method should return a match not for
+	 * the pre-flight request but for the expected actual request based on the URL
+	 * path, the HTTP methods from the "Access-Control-Request-Method" header, and
+	 * the headers from the "Access-Control-Request-Headers" header thus allowing
+	 * the CORS configuration to be obtained via {@link #getCorsConfigurations},
+	 *
+	 * @param exchange current exchange
+	 * @return {@code Mono} for the matching handler, if any
+	 */
+	protected abstract Mono<?> getHandlerInternal(ServerWebExchange exchange);
+
 	/**
 	 * Retrieve the CORS configuration for the given handler.
 	 * @param handler the handler to check (never {@code null}).

spring-web-reactive/src/main/java/org/springframework/web/reactive/handler/AbstractUrlHandlerMapping.java

@@ -96,12 +96,11 @@ public final Map<String, Object> getHandlerMap() {
 
 
 	@Override
-	public Mono<Object> getHandler(ServerWebExchange exchange) {
+	public Mono<Object> getHandlerInternal(ServerWebExchange exchange) {
 		String lookupPath = getPathHelper().getLookupPathForRequest(exchange);
 		Object handler;
 		try {
 			handler = lookupHandler(lookupPath, exchange);
-			handler = processCorsRequest(exchange, handler);
 		}
 		catch (Exception ex) {
 			return Mono.error(ex);

spring-web-reactive/src/main/java/org/springframework/web/reactive/result/method/AbstractHandlerMethodMapping.java

@@ -254,7 +254,7 @@ protected void handlerMethodsInitialized(Map<T, HandlerMethod> handlerMethods) {
 	 * @param exchange the current exchange
 	 */
 	@Override
-	public Mono<Object> getHandler(ServerWebExchange exchange) {
+	public Mono<HandlerMethod> getHandlerInternal(ServerWebExchange exchange) {
 		String lookupPath = getPathHelper().getLookupPathForRequest(exchange);
 		if (logger.isDebugEnabled()) {
 			logger.debug("Looking up handler method for path " + lookupPath);
@@ -279,7 +279,7 @@ public Mono<Object> getHandler(ServerWebExchange exchange) {
 			if (handlerMethod != null) {
 				handlerMethod = handlerMethod.createWithResolvedBean();
 			}
-			return Mono.justOrEmpty(processCorsRequest(exchange, handlerMethod));
+			return Mono.justOrEmpty(handlerMethod);
 		}
 		finally {
 			this.mappingRegistry.releaseReadLock();