RouterFunctionMapping provides getter for RouterFunction

Issue: SPR-15991

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/support/RouterFunctionMapping.java

@@ -70,6 +70,18 @@ public class RouterFunctionMapping extends AbstractHandlerMapping implements Ini
 	}
 
 
+	/**
+	 * Return the configured {@link RouterFunction}.
+	 * <p><strong>Note:</strong> When router functions are detected from the
+	 * ApplicationContext, this method may return {@code null} if invoked
+	 * prior to {@link #afterPropertiesSet()}.
+	 * @return the router function or {@code null}
+	 */
+	@Nullable
+	public RouterFunction<?> getRouterFunction() {
+		return this.routerFunction;
+	}
+
 	/**
 	 * Configure HTTP message readers to de-serialize the request body with.
 	 * <p>By default this is set to the {@link ServerCodecConfigurer}'s defaults.