fix: redirect on 308 (Permanent Redirect) too (#876)

* Redirect on 308 too

* Fix copyright

Author: chanseokoh

google-http-client/src/main/java/com/google/api/client/http/HttpStatusCodes.java

@@ -57,6 +57,9 @@ public class HttpStatusCodes {
   /** Status code for a resource that has temporarily moved to a new URI. */
   public static final int STATUS_CODE_TEMPORARY_REDIRECT = 307;
 
+  /** Status code for a resource that has permanently moved to a new URI. */
+  private static final int STATUS_CODE_PERMANENT_REDIRECT = 308;
+
   /** Status code for a request that could not be understood by the server. */
   public static final int STATUS_CODE_BAD_REQUEST = 400;
 
@@ -109,7 +112,7 @@ public static boolean isSuccess(int statusCode) {
 
   /**
    * Returns whether the given HTTP response status code is a redirect code {@code 301, 302, 303,
-   * 307}.
+   * 307, 308}.
    *
    * @since 1.11
    */
@@ -119,6 +122,7 @@ public static boolean isRedirect(int statusCode) {
       case HttpStatusCodes.STATUS_CODE_FOUND: // 302
       case HttpStatusCodes.STATUS_CODE_SEE_OTHER: // 303
       case HttpStatusCodes.STATUS_CODE_TEMPORARY_REDIRECT: // 307
+      case HttpStatusCodes.STATUS_CODE_PERMANENT_REDIRECT: // 308
         return true;
       default:
         return false;

google-http-client/src/test/java/com/google/api/client/http/HttpStatusCodesTest.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2019 Google LLC
+ *
+ * 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 com.google.api.client.http;
+
+import junit.framework.TestCase;
+
+/** Tests {@link HttpStatusCodes}. */
+public class HttpStatusCodesTest extends TestCase {
+
+  public void testIsRedirect_3xx() {
+    assertTrue(HttpStatusCodes.isRedirect(301));
+    assertTrue(HttpStatusCodes.isRedirect(302));
+    assertTrue(HttpStatusCodes.isRedirect(303));
+    assertTrue(HttpStatusCodes.isRedirect(307));
+    assertTrue(HttpStatusCodes.isRedirect(308));
+  }
+
+  public void testIsRedirect_non3xx() {
+    assertFalse(HttpStatusCodes.isRedirect(200));
+    assertFalse(HttpStatusCodes.isRedirect(401));
+    assertFalse(HttpStatusCodes.isRedirect(500));
+  }
+}