Add HttpBasic ClientWebRequestPostProcessor

Issue: SPR-14682

spring-web/src/main/java/org/springframework/web/client/reactive/ClientWebRequestPostProcessors.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2002-2016 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.web.client.reactive;
+
+import java.nio.charset.Charset;
+import java.util.Base64;
+import java.util.Base64.Encoder;
+
+import org.springframework.http.HttpHeaders;
+import org.springframework.util.Assert;
+
+/**
+ * Static factory methods for creating {@link ClientWebRequestPostProcesor} instances.
+ *
+ * @author Rob Winch
+ * @since 5.0
+ * @see DefaultClientWebRequestBuilder#apply(ClientWebRequestPostProcessors)
+ */
+public abstract class ClientWebRequestPostProcessors {
+
+	/**
+	 * Adds an Authorization header for HTTP Basic
+	 * @param username the username to add
+	 * @param password the password to add
+	 * @return the {@link ClientWebRequestPostProcessor} that adds the Authorization header
+	 */
+	public static ClientWebRequestPostProcessor httpBasic(String username, String password) {
+		Assert.notNull(username, "username cannot be null");
+		Assert.notNull(password, "password cannot be null");
+
+		return new ClientWebRequestPostProcessor() {
+
+			@Override
+			public ClientWebRequest postProcess(ClientWebRequest toPostProcess) {
+				String authorization = authorization(username, password);
+				toPostProcess.getHttpHeaders().set(HttpHeaders.AUTHORIZATION, authorization);
+				return toPostProcess;
+			}
+
+			private String authorization(String username, String password) {
+				String credentials = username + ":" + password;
+				return authorization(credentials);
+			}
+
+			private String authorization(String credentials) {
+				byte[] credentialBytes = credentials.getBytes(Charset.defaultCharset());
+				Encoder encoder = Base64.getEncoder();
+				String encodedCredentials = encoder.encodeToString(credentialBytes);
+				return "Basic " + encodedCredentials;
+			}
+		};
+	}
+
+}

spring-web/src/test/java/org/springframework/web/client/reactive/ClientWebRequestPostProcessorsTests.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2002-2016 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.web.client.reactive;
+
+import java.nio.charset.Charset;
+import java.util.Base64;
+import java.util.Base64.Encoder;
+
+import org.junit.Test;
+import org.springframework.http.HttpHeaders;
+
+
+import static org.junit.Assert.*;
+import static org.springframework.web.client.reactive.ClientWebRequestPostProcessors.*;
+import static org.springframework.web.client.reactive.ClientWebRequestBuilders.*;
+
+/**
+ *
+ * @author Rob Winch
+ * @since 5.0
+ */
+public class ClientWebRequestPostProcessorsTests {
+
+	@Test
+	public void httpBasicWhenUsernamePasswordThenHeaderSet() {
+		ClientWebRequest request = get("/").apply(httpBasic("user", "password")).build();
+		assertEquals(request.getHttpHeaders().getFirst(HttpHeaders.AUTHORIZATION), basic("user:password"));
+	}
+
+	@Test
+	public void httpBasicWhenUsernameEmptyThenHeaderSet() {
+		ClientWebRequest request = get("/").apply(httpBasic("", "password")).build();
+		assertEquals(request.getHttpHeaders().getFirst(HttpHeaders.AUTHORIZATION), basic(":password"));
+	}
+
+	@Test
+	public void httpBasicWhenPasswordEmptyThenHeaderSet() {
+		ClientWebRequest request = get("/").apply(httpBasic("user", "")).build();
+		assertEquals(request.getHttpHeaders().getFirst(HttpHeaders.AUTHORIZATION), basic("user:"));
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void httpBasicWhenUsernameNullThenIllegalArgumentException() {
+		httpBasic(null, "password");
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void httpBasicWhenPasswordNullThenIllegalArgumentException() {
+		httpBasic("username", null);
+	}
+
+	private static String basic(String string) {
+		Encoder encoder = Base64.getEncoder();
+		byte[] bytes = string.getBytes(Charset.defaultCharset());
+		return "Basic " + encoder.encodeToString(bytes);
+	}
+}