Issue 5231 - Use Java 7 features

adblockplussbrowser/src/org/adblockplus/sbrowser/contentblocker/engine/Engine.java

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 12 matching lines @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;
@@ skipping 33 matching lines @@
 
   public static final String USER_FILTERS_TITLE = "__filters";
   public static final String USER_EXCEPTIONS_TITLE = "__exceptions";
 
   public static final String ACTION_OPEN_SETTINGS = "com.samsung.android.sbrowser.contentBlocker.ACTION_SETTING";
   public static final String ACTION_UPDATE = "com.samsung.android.sbrowser.contentBlocker.ACTION_UPDATE";
   public static final String EASYLIST_URL = "https://easylist-downloads.adblockplus.org/easylist.txt";
 
   public static final String SUBSCRIPTIONS_EXCEPTIONSURL = "subscriptions_exceptionsurl";
 
-  public static final String CHARSET_UTF_8 = "UTF-8";
   private static final String PREFS_KEY_PREVIOUS_VERSION = "key_previous_version";
 
   // The value below specifies an interval of [x, 2*x[, where x =
   // INITIAL_UPDATE_CHECK_DELAY_SECONDS
   private static final long INITIAL_UPDATE_CHECK_DELAY_SECONDS = 5;
   private static final long UPDATE_CHECK_INTERVAL_MINUTES = 30;
   private static final long BROADCAST_COMBINATION_DELAY_MILLIS = 2500;
 
   public static final long MILLIS_PER_SECOND = 1000;
   public static final long MILLIS_PER_MINUTE = 60 * MILLIS_PER_SECOND;
   public static final long MILLIS_PER_HOUR = 60 * MILLIS_PER_MINUTE;
   public static final long MILLIS_PER_DAY = 24 * MILLIS_PER_HOUR;
 
   private final ReentrantLock accessLock = new ReentrantLock();
   private DefaultSubscriptions defaultSubscriptions;
   private Subscriptions subscriptions;
   private JSONPrefs jsonPrefs;
   private AppInfo appInfo;
-  private LinkedBlockingQueue<EngineEvent> engineEvents = new LinkedBlockingQueue<EngineEvent>();
+  private LinkedBlockingQueue<EngineEvent> engineEvents = new LinkedBlockingQueue<>();
   private Thread handlerThread;
   private Downloader downloader;
   private final Context serviceContext;
   private boolean wasFirstRun = false;
   private long nextUpdateBroadcast = Long.MAX_VALUE;
 
   private Engine(final Context context)
   {
     this.serviceContext = context;
   }
@@ skipping 228 matching lines @@
     final Engine engine = new Engine(context);
 
     // Migration data from previous version (if needed)
     engine.migrateFromPreviousVersion(context);
     Log.d(TAG, "Migration done");
 
     engine.appInfo = AppInfo.create(context);
 
     Log.d(TAG, "Creating engine, appInfo=" + engine.appInfo.toString());
 
-    final InputStream subscriptionsXml = context.getResources()
-        .openRawResource(R.raw.subscriptions);
-    try
+    try (final InputStream subscriptionsXml = context.getResources()
+        .openRawResource(R.raw.subscriptions))
     {
       engine.defaultSubscriptions = DefaultSubscriptions.fromStream(subscriptionsXml);
     }
-    finally
-    {
-      subscriptionsXml.close();
-    }
 
     Log.d(TAG, "Finished reading 'subscriptions.xml'");
     engine.subscriptions = Subscriptions.initialize(engine, getSubscriptionsDir(context),
         getFilterCacheDir(context));
 
-    final InputStream prefsJson = context.getResources().openRawResource(R.raw.prefs);
-    try
+    try (final InputStream prefsJson = context.getResources().openRawResource(R.raw.prefs))
     {
       engine.jsonPrefs = JSONPrefs.create(prefsJson);
     }
-    finally
-    {
-      prefsJson.close();
-    }
 
     Log.d(TAG, "Finished reading JSON preferences");
 
     // Check if this is a fresh start, if so: initialize bundled easylist.
     engine.wasFirstRun = engine.subscriptions.wasUnitialized();
     if (engine.subscriptions.wasUnitialized())
     {
       Log.d(TAG, "Subscription storage was uninitialized, initializing...");
 
-      final InputStream easylistTxt = context.getResources().openRawResource(R.raw.easylist);
-      try
+      try (final InputStream easylistTxt = context.getResources().openRawResource(R.raw.easylist))
       {
         final Subscription easylist = engine.subscriptions.add(Subscription
             .create(EASYLIST_URL)
             .parseLines(readLines(easylistTxt)));
         easylist.putMeta(Subscription.KEY_UPDATE_TIMESTAMP, "0");
         easylist.setEnabled(true);
       }
-      finally
-      {
-        easylistTxt.close();
-      }
       Log.d(TAG, "Added and enabled bundled easylist");
 
-      final InputStream exceptionsTxt = context.getResources()
-          .openRawResource(R.raw.exceptionrules);
-      try
+      try (final InputStream exceptionsTxt = context.getResources()
+          .openRawResource(R.raw.exceptionrules))
       {
         final Subscription exceptions = engine.subscriptions.add(Subscription
             .create(engine.getPrefsDefault(SUBSCRIPTIONS_EXCEPTIONSURL))
             .parseLines(readLines(exceptionsTxt)));
         exceptions.putMeta(Subscription.KEY_UPDATE_TIMESTAMP, "0");
         exceptions.setEnabled(true);
       }
-      finally
-      {
-        exceptionsTxt.close();
-      }
       Log.d(TAG, "Added and enabled bundled exceptionslist");
 
       int additional = 0;
       for (final Subscription sub : engine.defaultSubscriptions.createSubscriptions())
       {
         if (!engine.subscriptions.hasSubscription(sub.getId()))
         {
           additional++;
           engine.subscriptions.add(sub);
         }
@@ skipping 14 matching lines @@
     {
       engine.writeFileAndSendUpdateBroadcast();
     }
 
     return engine;
   }
 
   public static String readFileAsString(InputStream instream) throws IOException
   {
     final StringBuilder sb = new StringBuilder();
-    final BufferedReader r = new BufferedReader(new InputStreamReader(instream, CHARSET_UTF_8));
-    for (int ch = r.read(); ch != -1; ch = r.read())
+    try (final BufferedReader r = new BufferedReader(new InputStreamReader(

[anton, 2017/05/12 05:49:28]

Now `r` is closed automatically (as it's `Closeable` and `Autocloseable`) and it
closes InputStreamReader
instance and it closes `instream`. Previously `instream` was not closed here and
probably can be used later.

Please check this is desired behaviour (and not introduced by moving to JDK 7
only).

+        instream, StandardCharsets.UTF_8)))
     {
-      sb.append((char) ch);
+      for (int ch = r.read(); ch != -1; ch = r.read())
+      {
+        sb.append((char) ch);
+      }
     }
     return sb.toString();
   }
 
   public static List<String> readLines(InputStream instream) throws IOException
   {
-    final ArrayList<String> list = new ArrayList<String>();
-    final BufferedReader r = new BufferedReader(new InputStreamReader(instream, CHARSET_UTF_8));
-    for (String line = r.readLine(); line != null; line = r.readLine())
+    final ArrayList<String> list = new ArrayList<>();
+    try (final BufferedReader r = new BufferedReader(new InputStreamReader(

[anton, 2017/05/12 05:49:28]

Now `r` is closed automatically (as it's `Closeable` and `Autocloseable`) and it
closes InputStreamReader
instance and it closes `instream`. Previously `instream` was not closed here and
probably can be used later.

Please check this is desired behaviour (and not introduced by moving to JDK 7
only).

+        instream, StandardCharsets.UTF_8)))
     {
-      list.add(line);
+      for (String line = r.readLine(); line != null; line = r.readLine())
+      {
+        list.add(line);
+      }
     }
     return list;
   }
 
   public static File getOrCreateCachedFilterFile(Context context) throws IOException
   {
     final File cachedFilterFile = getCachedFilterFile(context);
     if (cachedFilterFile != null && cachedFilterFile.exists())
     {
       Log.d(TAG, "Cached filter file found: " + cachedFilterFile);
       return cachedFilterFile;
     }
 
     Log.d(TAG, "Cached filter file not found. Using dummy filter file");
     final File dummyFilterFile = getDummyFilterFile(context);
     if (!dummyFilterFile.exists())
     {
       Log.d(TAG, "Creating dummy filter file...");
       dummyFilterFile.getParentFile().mkdirs();
-      final BufferedWriter writer = new BufferedWriter(
-          new OutputStreamWriter(new FileOutputStream(dummyFilterFile), CHARSET_UTF_8));
-      try
+      try (final BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(
+          new FileOutputStream(dummyFilterFile), StandardCharsets.UTF_8)))
       {
         writeFilterHeaders(writer);
       }
-      finally
-      {
-        writer.close();
-      }
     }
     return dummyFilterFile;
   }
 
   public static void writeFilterHeaders(Writer writer) throws IOException
   {
     writer.write("[Adblock Plus 2.0]\n");
     writer.write("! This file was automatically created.\n");
   }
 
   private static void writeWhitelistedWebsites(Context context, File filterFile) throws IOException
   {
     Log.d(TAG, "Writing whitelisted websites...");
     final SharedPreferences prefs =
         PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext());
     final String key = context.getString(R.string.key_whitelisted_websites);
 
-    final Set<String> whitelistedWebsites = new TreeSet<String>();
+    final Set<String> whitelistedWebsites = new TreeSet<>();
     whitelistedWebsites.addAll(prefs.getStringSet(key, Collections.<String>emptySet()));
 
-    final BufferedWriter w = new BufferedWriter(
-        new OutputStreamWriter(new FileOutputStream(filterFile, true), CHARSET_UTF_8));
-    try
+    try (final BufferedWriter w = new BufferedWriter( new OutputStreamWriter(
+        new FileOutputStream(filterFile, true), StandardCharsets.UTF_8)))
     {
       for (final String url : whitelistedWebsites)
       {
         try
         {
           final URI uri = new URI(url);
           final String host = uri.getHost() != null ? uri.getHost() : uri.getPath();
           w.write("@@||" + host + "^$document");
           w.write('\n');
         }
         catch (URISyntaxException e)
         {
           Log.w(TAG, "Failed to parse whitelisted website: " + url);
           continue;
         }
       }
     }
-    finally
-    {
-      w.close();
-    }
   }
 
   private static File getCachedFilterFile(Context context)
   {
     final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
     final String cachedFilterPath = prefs.getString(context.getString(R.string.key_cached_filter_path), null);
     if (cachedFilterPath != null)
     {
       return new File(cachedFilterPath);
     }
@@ skipping 24 matching lines @@
     if (sub.getURL().getQuery() != null)
     {
       sb.append('&');
     }
     else
     {
       sb.append('?');
     }
 
     sb.append("addonName=");
-    sb.append(URLEncoder.encode(this.appInfo.addonName, CHARSET_UTF_8));
+    sb.append(URLEncoder.encode(this.appInfo.addonName, StandardCharsets.UTF_8.name()));
     sb.append("&addonVersion=");
-    sb.append(URLEncoder.encode(this.appInfo.addonVersion, CHARSET_UTF_8));
+    sb.append(URLEncoder.encode(this.appInfo.addonVersion, StandardCharsets.UTF_8.name()));
     sb.append("&application=");
-    sb.append(URLEncoder.encode(this.appInfo.application, CHARSET_UTF_8));
+    sb.append(URLEncoder.encode(this.appInfo.application, StandardCharsets.UTF_8.name()));
     sb.append("&applicationVersion=");
-    sb.append(URLEncoder.encode(this.appInfo.applicationVersion, CHARSET_UTF_8));
+    sb.append(URLEncoder.encode(this.appInfo.applicationVersion, StandardCharsets.UTF_8.name()));
     sb.append("&platform=");
-    sb.append(URLEncoder.encode(this.appInfo.platform, CHARSET_UTF_8));
+    sb.append(URLEncoder.encode(this.appInfo.platform, StandardCharsets.UTF_8.name()));
     sb.append("&platformVersion=");
-    sb.append(URLEncoder.encode(this.appInfo.platformVersion, CHARSET_UTF_8));
+    sb.append(URLEncoder.encode(this.appInfo.platformVersion, StandardCharsets.UTF_8.name()));
     sb.append("&lastVersion=");
     sb.append(sub.getVersion());
     sb.append("&downloadCount=");
     final long downloadCount = sub.getDownloadCount();
     if (downloadCount < 5)
     {
       sb.append(downloadCount);
     }
     else
     {
@@ skipping 121 matching lines @@
       this.id = id;
       this.enabled = enabled;
     }
   }
 
   private static class DownloadFinishedEvent extends EngineEvent
   {
     private final String id;
     private final int responseCode;
     private final String response;
-    private final HashMap<String, String> headers = new HashMap<String, String>();
+    private final HashMap<String, String> headers = new HashMap<>();
 
     public DownloadFinishedEvent(final String id,
         final int responseCode,
         final String response,
         final Map<String, String> headers)
     {
       super(EngineEvent.EngineEventType.DOWNLOAD_FINISHED);
       this.id = id;
       this.responseCode = responseCode;
       this.response = response;
       if (headers != null)
       {
         this.headers.putAll(headers);
       }
     }
   }
 
   public void enqueueDownload(final Subscription sub, final boolean forced) throws IOException
   {
     if (sub.getURL() != null && sub.shouldUpdate(forced))
     {
-      final HashMap<String, String> headers = new HashMap<String, String>();
+      final HashMap<String, String> headers = new HashMap<>();
       if (sub.isMetaDataValid() && sub.isFiltersValid())
       {
         final String lastModified = sub.getMeta(Subscription.KEY_HTTP_LAST_MODIFIED);
         if (!TextUtils.isEmpty(lastModified))
         {
           headers.put("If-Modified-Since", lastModified);
         }
         final String etag = sub.getMeta(Subscription.KEY_HTTP_ETAG);
         if (!TextUtils.isEmpty(etag))
         {
           headers.put("If-None-Match", etag);
         }
       }
       Log.d(TAG, headers.toString());
       this.downloader.enqueueDownload(this.createDownloadURL(sub), sub.getId(), headers);
     }
   }
 
   public void connectivityChanged()
   {
     this.downloader.connectivityChanged();
   }
 }