Add WebClient Bearer token support

Fixes: gh-5389

web/src/main/java/org/springframework/security/web/http/SecurityHeaders.java

@@ -0,0 +1,43 @@
+/*
+ * 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.web.http;
+
+import org.springframework.http.HttpHeaders;
+import org.springframework.util.Assert;
+
+import java.util.function.Consumer;
+
+/**
+ * Utilities for interacting with {@link HttpHeaders}
+ *
+ * @author Rob Winch
+ * @since 5.1
+ */
+public final class SecurityHeaders {
+
+	/**
+	 * Sets the provided value as a Bearer token in a header with the name of {@link HttpHeaders#AUTHORIZATION}
+	 * @param bearerTokenValue the bear token value
+	 * @return a {@link Consumer} that sets the header.
+	 */
+	public static Consumer<HttpHeaders> bearerToken(String bearerTokenValue) {
+		Assert.hasText(bearerTokenValue, "bearerTokenValue cannot be null");
+		return headers -> headers.set(HttpHeaders.AUTHORIZATION, "Bearer " + bearerTokenValue);
+	}
+
+	private SecurityHeaders() {}
+}