Bug 1241810 - FeedFetcher: Simple helper class for fetching feeds using ETag and If-Modified-Since headers. r?mcomella draft
authorSebastian Kaspari <s.kaspari@gmail.com>
Wed, 24 Feb 2016 11:49:45 -0800
changeset 335784 68ce6b1b15fa375cdee6fe469b2c78799a2caa60
parent 335783 8149ca3e54f7db435f7378faec705c9fafb36fbb
child 335785 90013e1fc4e7116bd3238f102be68fce6aa8d5da
push id11875
push users.kaspari@gmail.com
push dateTue, 01 Mar 2016 15:14:45 +0000
reviewersmcomella
bugs1241810
milestone47.0a1
Bug 1241810 - FeedFetcher: Simple helper class for fetching feeds using ETag and If-Modified-Since headers. r?mcomella MozReview-Commit-ID: EHxOcKwBsqe
mobile/android/base/java/org/mozilla/gecko/feeds/FeedFetcher.java
mobile/android/base/moz.build
new file mode 100644
--- /dev/null
+++ b/mobile/android/base/java/org/mozilla/gecko/feeds/FeedFetcher.java
@@ -0,0 +1,100 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.feeds;
+
+import org.mozilla.gecko.feeds.parser.Feed;
+import org.mozilla.gecko.feeds.parser.SimpleFeedParser;
+import org.mozilla.gecko.util.IOUtils;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import ch.boye.httpclientandroidlib.util.TextUtils;
+
+/**
+ * Helper class for fetching and parsing a feed.
+ */
+public class FeedFetcher {
+    private static final int CONNECT_TIMEOUT = 15000;
+    private static final int READ_TIMEOUT = 15000;
+
+    public static class FeedResponse {
+        public final Feed feed;
+        public final String etag;
+        public final String lastModified;
+
+        public FeedResponse(Feed feed, String etag, String lastModified) {
+            this.feed = feed;
+            this.etag = etag;
+            this.lastModified = lastModified;
+        }
+    }
+
+    /**
+     * Fetch and parse a feed from the given URL. Will return null if fetching or parsing failed.
+     */
+    public static FeedResponse fetchAndParseFeed(String url) {
+        return fetchAndParseFeedIfModified(url, null, null);
+    }
+
+    /**
+     * Fetch and parse a feed from the given URL using the given ETag and "Last modified" value.
+     * Will return null if fetching or parsing failed. Will also return null if the feed has not
+     * changed (ETag / Last-Modified-Since).
+     */
+    public static FeedResponse fetchAndParseFeedIfModified(String url, String eTag, String lastModified) {
+        HttpURLConnection connection = null;
+        InputStream stream = null;
+
+        try {
+            connection = (HttpURLConnection) new URL(url).openConnection();
+            connection.setInstanceFollowRedirects(true);
+            connection.setConnectTimeout(CONNECT_TIMEOUT);
+            connection.setReadTimeout(READ_TIMEOUT);
+
+            if (!TextUtils.isEmpty(eTag)) {
+                connection.setRequestProperty("If-None-Match", eTag);
+            }
+
+            if (!TextUtils.isEmpty(lastModified)) {
+                connection.setRequestProperty("If-Modified-Since", lastModified);
+            }
+
+            final int statusCode = connection.getResponseCode();
+
+            if (statusCode != HttpURLConnection.HTTP_OK) {
+                return null;
+            }
+
+            String responseEtag = connection.getHeaderField("ETag");
+            if (!TextUtils.isEmpty(responseEtag) && responseEtag.startsWith("W/")) {
+                // Weak ETag, get actual ETag value
+                responseEtag = responseEtag.substring(2);
+            }
+
+            final String updatedLastModified = connection.getHeaderField("Last-Modified");
+
+            stream = new BufferedInputStream(connection.getInputStream());
+
+            final SimpleFeedParser parser = new SimpleFeedParser();
+            final Feed feed = parser.parse(stream);
+
+            return new FeedResponse(feed, responseEtag, updatedLastModified);
+        } catch (IOException e) {
+            return null;
+        } catch (SimpleFeedParser.ParserException e) {
+            return null;
+        } finally {
+            if (connection != null) {
+                connection.disconnect();
+            }
+            IOUtils.safeStreamClose(stream);
+        }
+    }
+}
--- a/mobile/android/base/moz.build
+++ b/mobile/android/base/moz.build
@@ -270,16 +270,17 @@ gbjar.sources += ['java/org/mozilla/geck
     'favicons/decoders/FaviconDecoder.java',
     'favicons/decoders/ICODecoder.java',
     'favicons/decoders/IconDirectoryEntry.java',
     'favicons/decoders/LoadFaviconResult.java',
     'favicons/Favicons.java',
     'favicons/LoadFaviconTask.java',
     'favicons/OnFaviconLoadedListener.java',
     'favicons/RemoteFavicon.java',
+    'feeds/FeedFetcher.java',
     'feeds/parser/Feed.java',
     'feeds/parser/Item.java',
     'feeds/parser/SimpleFeedParser.java',
     'FilePicker.java',
     'FilePickerResultHandler.java',
     'FindInPageBar.java',
     'firstrun/DataPanel.java',
     'firstrun/FirstrunAnimationContainer.java',