checkstyle: Add ExplicitInitialization

F-Droid/src/com/google/zxing/encode/QRCodeEncoder.java

@@ -37,11 +37,11 @@ public final class QRCodeEncoder {
     private static final int BLACK = 0xFF000000;
 
     private int dimension = Integer.MIN_VALUE;
-    private String contents = null;
+    private String contents;
-    private String displayContents = null;
+    private String displayContents;
-    private String title = null;
+    private String title;
-    private BarcodeFormat format = null;
+    private BarcodeFormat format;
-    private boolean encoded = false;
+    private boolean encoded;
 
     public QRCodeEncoder(String data, Bundle bundle, String type, String format, int dimension) {
         this.dimension = dimension;

F-Droid/src/org/apache/commons/io/input/BoundedInputStream.java

@@ -42,7 +42,7 @@ public class BoundedInputStream extends InputStream {
     private final long max;
 
     /** the number of bytes already returned */
-    private long pos = 0;
+    private long pos;
 
     /** the marked position */
     private long mark = -1;

F-Droid/src/org/fdroid/fdroid/AppDetails.java

@@ -353,7 +353,7 @@ public class AppDetails extends AppCompatActivity implements ProgressListener, A
         }
     }
 
-    private boolean inProcessOfChangingConfiguration = false;
+    private boolean inProcessOfChangingConfiguration;
 
     /**
      * Attempt to extract the appId from the intent which launched this activity.
@@ -1424,8 +1424,8 @@ public class AppDetails extends AppCompatActivity implements ProgressListener, A
         private TextView progressPercent;
         private ImageButton cancelButton;
         protected final DisplayImageOptions displayImageOptions;
-        public static boolean installed = false;
+        public static boolean installed;
-        public static boolean updateWanted = false;
+        public static boolean updateWanted;
 
         public AppDetailsHeaderFragment() {
             displayImageOptions = new DisplayImageOptions.Builder()
@@ -1643,7 +1643,7 @@ public class AppDetails extends AppCompatActivity implements ProgressListener, A
 
         private AppDetailsData data;
         private AppInstallListener installListener;
-        private AppDetailsSummaryFragment summaryFragment = null;
+        private AppDetailsSummaryFragment summaryFragment;
 
         private FrameLayout headerView;
 

F-Droid/src/org/fdroid/fdroid/FDroid.java

@@ -60,11 +60,11 @@ public class FDroid extends ActionBarActivity {
 
     public static final String ACTION_ADD_REPO = "org.fdroid.fdroid.FDroid.ACTION_ADD_REPO";
 
-    private FDroidApp fdroidApp = null;
+    private FDroidApp fdroidApp;
 
     private ViewPager viewPager;
 
-    private TabManager tabManager = null;
+    private TabManager tabManager;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {

F-Droid/src/org/fdroid/fdroid/FDroidApp.java

@@ -78,7 +78,7 @@ public class FDroidApp extends Application {
     private static final org.spongycastle.jce.provider.BouncyCastleProvider spongyCastleProvider;
 
     @SuppressWarnings("unused")
-    BluetoothAdapter bluetoothAdapter = null;
+    BluetoothAdapter bluetoothAdapter;
 
     static {
         spongyCastleProvider = new org.spongycastle.jce.provider.BouncyCastleProvider();

F-Droid/src/org/fdroid/fdroid/FDroidCertPins.java

@@ -57,7 +57,7 @@ public class FDroidCertPins {
         "87e3bf322427c1405d2736c381e01d1a71d4a039",
     };
 
-    public static List<String> PINLIST = null;
+    public static List<String> PINLIST;
 
     public static String[] getPinList() {
         if (PINLIST == null) {

F-Droid/src/org/fdroid/fdroid/ProgressBufferedInputStream.java

@@ -16,7 +16,7 @@ public class ProgressBufferedInputStream extends BufferedInputStream {
     final Bundle data;
     final int totalBytes;
 
-    int currentBytes = 0;
+    int currentBytes;
 
     /**
      * Reports progress to the specified {@link ProgressListener}, with the

F-Droid/src/org/fdroid/fdroid/RepoUpdater.java

@@ -53,8 +53,8 @@ public class RepoUpdater {
     @NonNull protected final Repo repo;
     private List<App> apps = new ArrayList<>();
     private List<Apk> apks = new ArrayList<>();
-    private RepoUpdateRememberer rememberer = null;
+    private RepoUpdateRememberer rememberer;
-    protected boolean hasChanged = false;
+    protected boolean hasChanged;
     @Nullable protected ProgressListener progressListener;
 
     /**

F-Droid/src/org/fdroid/fdroid/RepoXMLHandler.java

@@ -40,8 +40,8 @@ public class RepoXMLHandler extends DefaultHandler {
     private final List<App> apps = new ArrayList<>();
     private final List<Apk> apksList = new ArrayList<>();
 
-    private App curapp = null;
+    private App curapp;
-    private Apk curapk = null;
+    private Apk curapk;
     private final StringBuilder curchars = new StringBuilder();
 
     // After processing the XML, these will be -1 if the index didn't specify

F-Droid/src/org/fdroid/fdroid/compat/TabManager.java

@@ -23,7 +23,7 @@ public class TabManager {
     private final ViewPager pager;
     private final FDroid parent;
     private final ActionBar actionBar;
-    private Spinner actionBarSpinner = null;
+    private Spinner actionBarSpinner;
 
     // Used to make sure we only search for the action bar spinner once
     // in each orientation.

F-Droid/src/org/fdroid/fdroid/data/ApkProvider.java

@@ -305,7 +305,7 @@ public class ApkProvider extends FDroidProvider {
 
     private static class Query extends QueryBuilder {
 
-        private boolean repoTableRequired = false;
+        private boolean repoTableRequired;
 
         @Override
         protected String getRequiredTables() {

F-Droid/src/org/fdroid/fdroid/data/AppProvider.java

@@ -237,7 +237,7 @@ public class AppProvider extends FDroidProvider {
      */
     private static class AppQuerySelection extends QuerySelection {
 
-        private boolean naturalJoinToInstalled = false;
+        private boolean naturalJoinToInstalled;
 
         public AppQuerySelection() {
             // The same as no selection, because "1" will always resolve to true when executing the SQL query.
@@ -286,10 +286,10 @@ public class AppProvider extends FDroidProvider {
 
     private static class Query extends QueryBuilder {
 
-        private boolean isSuggestedApkTableAdded = false;
+        private boolean isSuggestedApkTableAdded;
-        private boolean requiresInstalledTable = false;
+        private boolean requiresInstalledTable;
-        private boolean categoryFieldAdded = false;
+        private boolean categoryFieldAdded;
-        private boolean countFieldAppended = false;
+        private boolean countFieldAppended;
 
         @Override
         protected String getRequiredTables() {

F-Droid/src/org/fdroid/fdroid/data/FDroidProvider.java

@@ -25,7 +25,7 @@ public abstract class FDroidProvider extends ContentProvider {
 
     private DBHelper dbHelper;
 
-    private boolean isApplyingBatch = false;
+    private boolean isApplyingBatch;
 
     protected abstract String getTableName();
 

F-Droid/src/org/fdroid/fdroid/data/NewRepoConfig.java

@@ -18,7 +18,7 @@ public class NewRepoConfig {
     private static final String TAG = "NewRepoConfig";
 
     private String errorMessage;
-    private boolean isValidRepo = false;
+    private boolean isValidRepo;
 
     private String uriString;
     private String host;

F-Droid/src/org/fdroid/fdroid/data/QueryBuilder.java

@@ -7,8 +7,8 @@ abstract class QueryBuilder {
 
     private final List<String> fields = new ArrayList<>();
     private final StringBuilder tables = new StringBuilder(getRequiredTables());
-    private String selection = null;
+    private String selection;
-    private String orderBy = null;
+    private String orderBy;
 
     protected abstract String getRequiredTables();
 

F-Droid/src/org/fdroid/fdroid/localrepo/LocalRepoManager.java

@@ -82,8 +82,8 @@ public final class LocalRepoManager {
     private final Map<String, App> apps = new HashMap<>();
 
     public final SanitizedFile xmlIndex;
-    private SanitizedFile xmlIndexJar = null;
+    private SanitizedFile xmlIndexJar;
-    private SanitizedFile xmlIndexJarUnsigned = null;
+    private SanitizedFile xmlIndexJarUnsigned;
     public final SanitizedFile webRoot;
     public final SanitizedFile fdroidDir;
     public final SanitizedFile fdroidDirCaps;

F-Droid/src/org/fdroid/fdroid/localrepo/peers/PeerFinder.java

@@ -16,7 +16,7 @@ public abstract class PeerFinder<T extends Peer> {
 
     private static final String TAG = "PeerFinder";
 
-    protected boolean isScanning = false;
+    protected boolean isScanning;
     protected final Context context;
 
     public abstract void scan();

F-Droid/src/org/fdroid/fdroid/localrepo/type/BluetoothSwap.java

@@ -18,17 +18,17 @@ public final class BluetoothSwap extends SwapType {
     private static final String TAG = "BluetoothSwap";
     public static final String BLUETOOTH_NAME_TAG = "FDroid:";
 
-    private static BluetoothSwap mInstance = null;
+    private static BluetoothSwap mInstance;
 
     @NonNull
     private final BluetoothAdapter adapter;
     private BroadcastReceiver receiver;
-    private boolean isDiscoverable = false;
+    private boolean isDiscoverable;
 
     @Nullable
     private BluetoothServer server;
 
-    private String deviceBluetoothName = null;
+    private String deviceBluetoothName;
 
     public static SwapType create(@NonNull Context context) {
         BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();

F-Droid/src/org/fdroid/fdroid/localrepo/type/WifiSwap.java

@@ -23,7 +23,7 @@ public class WifiSwap extends SwapType {
 
     private static final String TAG = "WifiSwap";
 
-    private Handler webServerThreadHandler = null;
+    private Handler webServerThreadHandler;
     private LocalHTTPD localHttpd;
     private final BonjourBroadcast bonjourBroadcast;
 

F-Droid/src/org/fdroid/fdroid/net/ApkDownloader.java

@@ -61,7 +61,7 @@ public class ApkDownloader implements AsyncDownloader.Listener {
     public static final int ERROR_DOWNLOAD_FAILED = 102;
 
     private static final String EVENT_SOURCE_ID = "sourceId";
-    private static long downloadIdCounter = 0;
+    private static long downloadIdCounter;
 
     /**
      * Used as a key to pass data through with an error event, explaining the type of event.
@@ -76,8 +76,8 @@ public class ApkDownloader implements AsyncDownloader.Listener {
     @NonNull private final SanitizedFile potentiallyCachedFile;
 
     private ProgressListener listener;
-    private AsyncDownloader dlWrapper = null;
+    private AsyncDownloader dlWrapper;
-    private boolean isComplete = false;
+    private boolean isComplete;
 
     private final long id = ++downloadIdCounter;
 

F-Droid/src/org/fdroid/fdroid/net/AsyncDownloadWrapper.java

@@ -17,7 +17,7 @@ class AsyncDownloadWrapper extends Handler implements AsyncDownloader {
     private static final String MSG_DATA            = "data";
 
     private final Downloader downloader;
-    private DownloadThread downloadThread = null;
+    private DownloadThread downloadThread;
 
     private final Listener listener;
 

F-Droid/src/org/fdroid/fdroid/net/Downloader.java

@@ -31,9 +31,9 @@ public abstract class Downloader {
     private final File outputFile;
 
     protected final URL sourceUrl;
-    protected String cacheTag = null;
+    protected String cacheTag;
-    protected int bytesRead = 0;
+    protected int bytesRead;
-    protected int totalBytes = 0;
+    protected int totalBytes;
 
     public abstract InputStream getInputStream() throws IOException;
     public abstract void close();

F-Droid/src/org/fdroid/fdroid/net/HttpDownloader.java

@@ -34,7 +34,7 @@ public class HttpDownloader extends Downloader {
     protected HttpURLConnection connection;
     private InputStream stream;
     private int statusCode = -1;
-    private boolean onlyStream = false;
+    private boolean onlyStream;
 
     HttpDownloader(Context context, URL url, File destFile)
             throws FileNotFoundException, MalformedURLException {

F-Droid/src/org/fdroid/fdroid/net/bluetooth/BluetoothConnection.java

@@ -16,8 +16,8 @@ public class BluetoothConnection {
 
     private static final String TAG = "BluetoothConnection";
 
-    private InputStream input = null;
+    private InputStream input;
-    private OutputStream output = null;
+    private OutputStream output;
     protected final BluetoothSocket socket;
 
     public BluetoothConnection(BluetoothSocket socket) throws IOException {

F-Droid/src/org/fdroid/fdroid/net/bluetooth/BluetoothServer.java

@@ -35,7 +35,7 @@ public class BluetoothServer extends Thread {
 
     private final File webRoot;
     private final BluetoothSwap swap;
-    private boolean isRunning = false;
+    private boolean isRunning;
 
     public BluetoothServer(BluetoothSwap swap, File webRoot) {
         this.webRoot = webRoot;

F-Droid/src/org/fdroid/fdroid/net/bluetooth/httpish/Response.java

@@ -152,7 +152,7 @@ public class Response {
         private InputStream contentStream;
         private int statusCode = 200;
         private int fileSize = -1;
-        private String etag = null;
+        private String etag;
 
         public Builder() { }
 

F-Droid/src/org/fdroid/fdroid/privileged/views/AppDiff.java

@@ -28,7 +28,7 @@ public class AppDiff {
     public final PackageManager mPm;
     public final PackageInfo mPkgInfo;
 
-    public ApplicationInfo mInstalledAppInfo = null;
+    public ApplicationInfo mInstalledAppInfo;
 
     public AppDiff(PackageManager mPm, Uri mPackageURI) {
         this.mPm = mPm;

F-Droid/src/org/fdroid/fdroid/privileged/views/InstallConfirmActivity.java

@@ -56,8 +56,8 @@ public class InstallConfirmActivity extends Activity implements OnCancelListener
     // Buttons to indicate user acceptance
     private Button mOk;
     private Button mCancel;
-    CaffeinatedScrollView mScrollView = null;
+    CaffeinatedScrollView mScrollView;
-    private boolean mOkCanInstall = false;
+    private boolean mOkCanInstall;
 
     private static final String TAB_ID_ALL = "all";
     private static final String TAB_ID_NEW = "new";

F-Droid/src/org/fdroid/fdroid/views/ManageReposActivity.java

@@ -91,7 +91,7 @@ public class ManageReposActivity extends ActionBarActivity {
      * True if activity started with an intent such as from QR code. False if
      * opened from, e.g. the main menu.
      */
-    private boolean isImportingRepo = false;
+    private boolean isImportingRepo;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {

F-Droid/src/org/fdroid/fdroid/views/fragments/AvailableAppsFragment.java

@@ -42,8 +42,8 @@ public class AvailableAppsFragment extends AppListFragment implements
 
     private List<String> categories;
     private Spinner categorySpinner;
-    private String currentCategory = null;
+    private String currentCategory;
-    private AppListAdapter adapter = null;
+    private AppListAdapter adapter;
 
     @Override
     protected String getFromTitle() {

F-Droid/src/org/fdroid/fdroid/views/fragments/ThemeableListFragment.java

@@ -25,7 +25,7 @@ public abstract class ThemeableListFragment extends ListFragment {
         return headerView;
     }
 
-    private View headerView = null;
+    private View headerView;
 
     private View getHeaderView(LayoutInflater inflater, ViewGroup container) {
         if (getHeaderLayout() > 0) {

F-Droid/src/org/fdroid/fdroid/views/swap/SwapWorkflowActivity.java

@@ -115,9 +115,9 @@ public class SwapWorkflowActivity extends AppCompatActivity {
 
     private Toolbar toolbar;
     private InnerView currentView;
-    private boolean hasPreparedLocalRepo = false;
+    private boolean hasPreparedLocalRepo;
-    private PrepareSwapRepo updateSwappableAppsTask = null;
+    private PrepareSwapRepo updateSwappableAppsTask;
-    private NewRepoConfig confirmSwapConfig = null;
+    private NewRepoConfig confirmSwapConfig;
 
     @NonNull
     private final ServiceConnection serviceConnection = new ServiceConnection() {
@@ -138,7 +138,7 @@ public class SwapWorkflowActivity extends AppCompatActivity {
     };
 
     @Nullable
-    private SwapService service = null;
+    private SwapService service;
 
     @NonNull
     public SwapService getService() {

config/checkstyle/checkstyle.xml

@@ -47,6 +47,7 @@
         <module name="WhitespaceAfter" />
         <module name="WhitespaceAround" />
         <module name="UnnecessaryParentheses" />
+        <module name="ExplicitInitialization" />
 
         <module name="ModifierOrder" />
         <module name="RedundantModifier" />