add Atom.setSlugHeader

https://codereview.appspot.com/7518046/

Author: Yaniv Inbar

google-http-client/src/main/java/com/google/api/client/xml/atom/Atom.java

@@ -14,12 +14,17 @@
 
 package com.google.api.client.xml.atom;
 
+import com.google.api.client.http.HttpHeaders;
 import com.google.api.client.http.HttpMediaType;
 import com.google.api.client.util.Charsets;
 import com.google.api.client.util.Experimental;
+import com.google.api.client.util.Lists;
 import com.google.api.client.util.Preconditions;
+import com.google.api.client.util.escape.PercentEscaper;
 import com.google.api.client.xml.Xml;
 
+import java.util.Arrays;
+
 /**
  * {@link Experimental} <br/>
  * Atom Utilities.
@@ -45,6 +50,10 @@ public final class Atom {
   public static final String MEDIA_TYPE =
       new HttpMediaType("application/atom+xml").setCharsetParameter(Charsets.UTF_8).build();
 
+  /** Escaper for the {@code Slug} header. */
+  private static final PercentEscaper SLUG_ESCAPER =
+      new PercentEscaper(" !\"#$&'()*+,-./:;<=>?@[\\]^_`{|}~", false);
+
   static final class StopAtAtomEntry extends Xml.CustomizeParser {
 
     static final StopAtAtomEntry INSTANCE = new StopAtAtomEntry();
@@ -68,4 +77,18 @@ public static void checkContentType(String contentType) {
     Preconditions.checkArgument(HttpMediaType.equalsIgnoreParameters(MEDIA_TYPE, contentType),
         "Wrong content type: expected <" + MEDIA_TYPE + "> but got <%s>", contentType);
   }
+
+  /**
+   * Sets the {@code "Slug"} header, properly escaping the header value. See <a
+   * href="http://tools.ietf.org/html/rfc5023#section-9.7">The Slug Header</a>.
+   *
+   * @since 1.14
+   */
+  public static void setSlugHeader(HttpHeaders headers, String value) {
+    if (value == null) {
+      headers.remove("Slug");
+    } else {
+      headers.set("Slug", Lists.newArrayList(Arrays.asList(SLUG_ESCAPER.escape(value))));
+    }
+  }
 }

google-http-client/src/test/java/com/google/api/client/xml/AtomTest.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2013 Google Inc.
+ *
+ * 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.xml;
+
+import com.google.api.client.http.HttpHeaders;
+import com.google.api.client.xml.atom.Atom;
+
+import junit.framework.TestCase;
+import org.junit.Assert;
+
+import java.util.List;
+
+/**
+ * Tests {@link Atom}.
+ *
+ * @author Yaniv Inbar
+ */
+public class AtomTest extends TestCase {
+
+  @SuppressWarnings("unchecked")
+  public void testSetSlugHeader() {
+    HttpHeaders headers = new HttpHeaders();
+    assertNull(headers.get("Slug"));
+    subtestSetSlugHeader(headers, "value", "value");
+    subtestSetSlugHeader(
+        headers, " !\"#$&'()*+,-./:;<=>?@[\\]^_`{|}~", " !\"#$&'()*+,-./:;<=>?@[\\]^_`{|}~");
+    subtestSetSlugHeader(headers, "%D7%99%D7%A0%D7%99%D7%91", "יניב");
+    subtestSetSlugHeader(headers, null, null);
+  }
+
+  @SuppressWarnings("unchecked")
+  public void subtestSetSlugHeader(HttpHeaders headers, String expectedValue, String value) {
+    Atom.setSlugHeader(headers, value);
+    if (value == null) {
+      assertNull(headers.get("Slug"));
+    } else {
+      Assert.assertArrayEquals(
+          new String[] {expectedValue}, ((List<String>) headers.get("Slug")).toArray());
+    }
+  }
+}