Add static methods for ServletOAuth2AuthorizedClientExchangeFilterFunction

This will allow us to break up
ServletOAuth2AuthorizedClientExchangeFilterFunction into multiple
components if we decide to later.

Issue: gh-5545

Author: rwinch

oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/web/reactive/function/client/OAuth2ExchangeFilterFunctions.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2002-2018 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
+ *
+ *      http://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.security.oauth2.client.web.reactive.function.client;
+
+import org.springframework.security.oauth2.client.web.OAuth2AuthorizedClientRepository;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import java.util.function.Consumer;
+
+/**
+ * @author Rob Winch
+ * @since 5.1
+ */
+public final class OAuth2ExchangeFilterFunctions {
+
+	/**
+	 * Configures the WebClient for OAuth2 support in a servlet environment.
+	 * @param repository the repository to use
+	 * @return the {@link Consumer} to configure the WebClient
+	 */
+	public static Consumer<WebClient.Builder> oauth2ServletConfig(OAuth2AuthorizedClientRepository repository) {
+		return new ServletOAuth2AuthorizedClientExchangeFilterFunction(repository)
+				.oauth2Configuration();
+	}
+
+	/**
+	 * Configures the WebClient for OAuth2 support in a servlet environment.
+	 * @return the {@link Consumer} to configure the WebClient
+	 */
+	public static Consumer<WebClient.Builder> oauth2ServletConfig() {
+		return new ServletOAuth2AuthorizedClientExchangeFilterFunction()
+				.oauth2Configuration();
+	}
+
+	private OAuth2ExchangeFilterFunctions() {}
+}