Merge pull request #2852 from nextcloud/codacy

further codacy improvements

build.gradle

@@ -14,7 +14,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.3'
+        classpath 'com.android.tools.build:gradle:3.1.4'
         classpath 'org.codehaus.groovy:groovy-all:2.4.12' 
         classpath('com.dicedmelon.gradle:jacoco-android:0.1.2') { 
             exclude group: 'org.codehaus.groovy', module: 'groovy-all' 

src/main/java/com/owncloud/android/authentication/AccountAuthenticatorActivity.java

@@ -34,8 +34,8 @@ import android.support.v7.app.AppCompatActivity;
 
 public class AccountAuthenticatorActivity extends AppCompatActivity {
 
-    private AccountAuthenticatorResponse mAccountAuthenticatorResponse = null;
-    private Bundle mResultBundle = null;
+    private AccountAuthenticatorResponse mAccountAuthenticatorResponse;
+    private Bundle mResultBundle;
 
 
     /**

src/main/java/com/owncloud/android/authentication/AccountUtils.java

@@ -36,7 +36,6 @@ import com.owncloud.android.ui.activity.ManageAccountsActivity;
 
 
 public class AccountUtils {
-    private static final String TAG = AccountUtils.class.getSimpleName();
     private static final String PREF_SELECT_OC_ACCOUNT = "select_oc_account";
 
     public static final int ACCOUNT_VERSION = 1;

src/main/java/com/owncloud/android/authentication/AuthenticatorActivity.java

@@ -207,10 +207,10 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
 
     private TextWatcher mHostUrlInputWatcher;
     private String mServerStatusText = "";
-    private int mServerStatusIcon = 0;
+    private int mServerStatusIcon;
 
-    private boolean mServerIsChecked = false;
-    private boolean mServerIsValid = false;
+    private boolean mServerIsChecked;
+    private boolean mServerIsValid;
 
     private GetServerInfoOperation.ServerInfo mServerInfo = new GetServerInfoOperation.ServerInfo();
 
@@ -227,7 +227,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
     private WebView mLoginWebView;
 
     private String mAuthStatusText = "";
-    private int mAuthStatusIcon = 0;
+    private int mAuthStatusIcon;
 
     private String mAuthToken = "";
     private AuthenticatorAsyncTask mAsyncTask;
@@ -246,7 +246,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
     private String webViewPassword;
     private TextInputLayout mUsernameInputLayout;
     private TextInputLayout mPasswordInputLayout;
-    private boolean forceOldLoginMethod = false;
+    private boolean forceOldLoginMethod;
 
     /**
      * {@inheritDoc}

src/main/java/com/owncloud/android/datamodel/ArbitraryDataProvider.java

@@ -29,12 +29,11 @@ import android.net.Uri;
 import com.owncloud.android.db.ProviderMeta;
 import com.owncloud.android.lib.common.utils.Log_OC;
 
-import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Database provider for handling the persistence aspects of arbitrary data table.
  */
-
 public class ArbitraryDataProvider {
     static private final String TAG = ArbitraryDataProvider.class.getSimpleName();
 
@@ -56,7 +55,7 @@ public class ArbitraryDataProvider {
         );
     }
 
-    public int deleteForKeyWhereAccountNotIn(ArrayList<String> accounts, String key) {
+    public int deleteForKeyWhereAccountNotIn(List<String> accounts, String key) {
         return contentResolver.delete(
                 ProviderMeta.ProviderTableMeta.CONTENT_URI_ARBITRARY_DATA,
                 ProviderMeta.ProviderTableMeta.ARBITRARY_DATA_CLOUD_ID + " NOT IN (?) AND " +

src/main/java/com/owncloud/android/datamodel/DecryptedFolderMetadata.java

@@ -22,14 +22,14 @@
 package com.owncloud.android.datamodel;
 
 import java.util.HashMap;
+import java.util.Map;
 
 /**
  * Decrypted class representation of metadata json of folder metadata
  */
-
 public class DecryptedFolderMetadata {
     private Metadata metadata;
-    private HashMap<String, DecryptedFile> files;
+    private Map<String, DecryptedFile> files;
 
     public DecryptedFolderMetadata() {
         this.metadata = new Metadata();
@@ -49,24 +49,24 @@ public class DecryptedFolderMetadata {
         this.metadata = metadata;
     }
 
-    public HashMap<String, DecryptedFile> getFiles() {
+    public Map<String, DecryptedFile> getFiles() {
         return files;
     }
 
-    public void setFiles(HashMap<String, DecryptedFile> files) {
+    public void setFiles(Map<String, DecryptedFile> files) {
         this.files = files;
     }
 
     public static class Metadata {
-        private HashMap<Integer, String> metadataKeys; // each keys is encrypted on its own, decrypt on use
+        private Map<Integer, String> metadataKeys; // each keys is encrypted on its own, decrypt on use
         private Sharing sharing;
         private int version;
 
-        public HashMap<Integer, String> getMetadataKeys() {
+        public Map<Integer, String> getMetadataKeys() {
             return metadataKeys;
         }
 
-        public void setMetadataKeys(HashMap<Integer, String> metadataKeys) {
+        public void setMetadataKeys(Map<Integer, String> metadataKeys) {
             this.metadataKeys = metadataKeys;
         }
 
@@ -93,26 +93,26 @@ public class DecryptedFolderMetadata {
     }
 
     public static class Encrypted {
-        private HashMap<Integer, String> metadataKeys;
+        private Map<Integer, String> metadataKeys;
 
-        public HashMap<Integer, String> getMetadataKeys() {
+        public Map<Integer, String> getMetadataKeys() {
             return metadataKeys;
         }
 
-        public void setMetadataKeys(HashMap<Integer, String> metadataKeys) {
+        public void setMetadataKeys(Map<Integer, String> metadataKeys) {
             this.metadataKeys = metadataKeys;
         }
     }
 
     public static class Sharing {
-        private HashMap<String, String> recipient;
+        private Map<String, String> recipient;
         private String signature;
 
-        public HashMap<String, String> getRecipient() {
+        public Map<String, String> getRecipient() {
             return recipient;
         }
 
-        public void setRecipient(HashMap<String, String> recipient) {
+        public void setRecipient(Map<String, String> recipient) {
             this.recipient = recipient;
         }
 

src/main/java/com/owncloud/android/datamodel/EncryptedFolderMetadata.java

@@ -21,7 +21,7 @@
 
 package com.owncloud.android.datamodel;
 
-import java.util.HashMap;
+import java.util.Map;
 
 /**
  * Encrypted class representation of metadata json of folder metadata
@@ -29,9 +29,9 @@ import java.util.HashMap;
 
 public class EncryptedFolderMetadata {
     private DecryptedFolderMetadata.Metadata metadata;
-    private HashMap<String, EncryptedFile> files;
+    private Map<String, EncryptedFile> files;
     
-    public EncryptedFolderMetadata(DecryptedFolderMetadata.Metadata metadata, HashMap<String, EncryptedFile> files) {
+    public EncryptedFolderMetadata(DecryptedFolderMetadata.Metadata metadata, Map<String, EncryptedFile> files) {
         this.metadata = metadata;
         this.files = files;
     }
@@ -44,11 +44,11 @@ public class EncryptedFolderMetadata {
         this.metadata = metadata;
     }
 
-    public HashMap<String, EncryptedFile> getFiles() {
+    public Map<String, EncryptedFile> getFiles() {
         return files;
     }
 
-    public void setFiles(HashMap<String, EncryptedFile> files) {
+    public void setFiles(Map<String, EncryptedFile> files) {
         this.files = files;
     }
 
@@ -91,4 +91,3 @@ public class EncryptedFolderMetadata {
         }
     }
 }
-

src/main/java/com/owncloud/android/datamodel/ExternalLinksProvider.java

@@ -31,6 +31,7 @@ import com.owncloud.android.lib.common.ExternalLinkType;
 import com.owncloud.android.lib.common.utils.Log_OC;
 
 import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Database provider for handling the persistence aspects of {@link com.owncloud.android.lib.common.ExternalLink}s.
@@ -82,7 +83,7 @@ public class ExternalLinksProvider {
      *
      * @return external links, empty if none exists
      */
-    public ArrayList<ExternalLink> getExternalLink(ExternalLinkType type) {
+    public List<ExternalLink> getExternalLink(ExternalLinkType type) {
         Cursor cursor = mContentResolver.query(
                 ProviderMeta.ProviderTableMeta.CONTENT_URI_EXTERNAL_LINKS,
                 null,
@@ -92,7 +93,7 @@ public class ExternalLinksProvider {
         );
 
         if (cursor != null) {
-            ArrayList<ExternalLink> list = new ArrayList<>();
+            List<ExternalLink> list = new ArrayList<>();
             if (cursor.moveToFirst()) {
                 do {
                     ExternalLink externalLink = createExternalLinkFromCursor(cursor);

src/main/java/com/owncloud/android/datamodel/FileDataStorageManager.java

@@ -1656,7 +1656,7 @@ public class FileDataStorageManager {
 
     }
 
-    public ArrayList<OCShare> getSharesWithForAFile(String filePath, String accountName) {
+    public List<OCShare> getSharesWithForAFile(String filePath, String accountName) {
         // Condition
         String where = ProviderTableMeta.OCSHARES_PATH + AND
                 + ProviderTableMeta.OCSHARES_ACCOUNT_OWNER + AND

src/main/java/com/owncloud/android/datamodel/FilesystemDataProvider.java

@@ -29,7 +29,6 @@ import com.owncloud.android.lib.common.utils.Log_OC;
 
 import java.io.BufferedInputStream;
 import java.io.FileInputStream;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.HashSet;

src/main/java/com/owncloud/android/datamodel/OCFile.java

@@ -303,8 +303,7 @@ public class OCFile implements Parcelable, Comparable<OCFile>, ServerFileInterfa
      */
     public boolean existsOnDevice() {
         if (mLocalPath != null && mLocalPath.length() > 0) {
-            File file = new File(mLocalPath);
-            return (file.exists());
+            return new File(mLocalPath).exists();
         }
         return false;
     }
@@ -588,7 +587,7 @@ public class OCFile implements Parcelable, Comparable<OCFile>, ServerFileInterfa
      */
     public String getParentRemotePath() {
         String parentPath = new File(this.getRemotePath()).getParent();
-        return (parentPath.endsWith("/")) ? parentPath : (parentPath + "/");
+        return parentPath.endsWith("/") ? parentPath : parentPath + "/";
     }
 
     /**
@@ -777,7 +776,7 @@ public class OCFile implements Parcelable, Comparable<OCFile>, ServerFileInterfa
 
     public boolean isSharedWithMe() {
         String permissions = getPermissions();
-        return (permissions != null && permissions.contains(PERMISSION_SHARED_WITH_ME));
+        return permissions != null && permissions.contains(PERMISSION_SHARED_WITH_ME);
     }
 
     public boolean canReshare() {

src/main/java/com/owncloud/android/datamodel/SyncedFolderProvider.java

@@ -309,7 +309,7 @@ public class SyncedFolderProvider extends Observable {
      * @param ids     the list of ids to be excluded from deletion.
      * @return number of deleted records.
      */
-    public int deleteSyncedFoldersNotInList(Context context, ArrayList<Long> ids) {
+    public int deleteSyncedFoldersNotInList(Context context, List<Long> ids) {
         int result = mContentResolver.delete(
                 ProviderMeta.ProviderTableMeta.CONTENT_URI_SYNCED_FOLDERS,
                 ProviderMeta.ProviderTableMeta._ID + " NOT IN (?)",

src/main/java/com/owncloud/android/datamodel/ThumbnailsCacheManager.java

@@ -71,7 +71,7 @@ import java.io.FileNotFoundException;
 import java.io.InputStream;
 import java.lang.ref.WeakReference;
 import java.net.URLEncoder;
-import java.util.ArrayList;
+import java.util.List;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
@@ -379,7 +379,7 @@ public class ThumbnailsCacheManager {
     public static class ThumbnailGenerationTask extends AsyncTask<ThumbnailGenerationTaskObject, Void, Bitmap> {
         private final WeakReference<ImageView> mImageViewReference;
         private static Account mAccount;
-        private ArrayList<ThumbnailGenerationTask> mAsyncTasks = null;
+        private List<ThumbnailGenerationTask> mAsyncTasks;
         private Object mFile;
         private String mImageKey = null;
         private FileDataStorageManager mStorageManager;
@@ -391,7 +391,7 @@ public class ThumbnailsCacheManager {
         }
 
         public ThumbnailGenerationTask(ImageView imageView, FileDataStorageManager storageManager,
-                                       Account account, ArrayList<ThumbnailGenerationTask> asyncTasks)
+                                       Account account, List<ThumbnailGenerationTask> asyncTasks)
                 throws IllegalArgumentException {
             // Use a WeakReference to ensure the ImageView can be garbage collected
             mImageViewReference = new WeakReference<ImageView>(imageView);

src/main/java/com/owncloud/android/datamodel/UploadsStorageManager.java

@@ -320,7 +320,7 @@ public class UploadsStorageManager extends Observable {
             upload.setUploadStatus(
                     UploadStatus.fromValue(c.getInt(c.getColumnIndex(ProviderTableMeta.UPLOADS_STATUS)))
             );
-            upload.setLocalAction(c.getInt(c.getColumnIndex((ProviderTableMeta.UPLOADS_LOCAL_BEHAVIOUR))));
+            upload.setLocalAction(c.getInt(c.getColumnIndex(ProviderTableMeta.UPLOADS_LOCAL_BEHAVIOUR)));
             upload.setForceOverwrite(c.getInt(
                     c.getColumnIndex(ProviderTableMeta.UPLOADS_FORCE_OVERWRITE)) == 1);
             upload.setCreateRemoteFolder(c.getInt(

src/main/java/com/owncloud/android/datastorage/DataStorageProvider.java

@@ -42,7 +42,7 @@ import java.util.Vector;
  */
 public class DataStorageProvider {
 
-    private static final Vector<IStoragePointProvider> mStorageProviders = new Vector<>();
+    private static final List<IStoragePointProvider> mStorageProviders = new ArrayList<>();
     private static final UniqueStorageList mCachedStoragePoints = new UniqueStorageList();
     private static final DataStorageProvider sInstance = new DataStorageProvider() {{
         // There is no system wide way to get usb storage so we need to provide multiple

src/main/java/com/owncloud/android/features/FeatureList.java

@@ -44,8 +44,8 @@ public class FeatureList {
     private static final int VERSION_3_3_0 = 30030099;
     private static final int BETA_VERSION_0 = 0;
 
-    static public ArrayList<FeatureItem> get(boolean isMultiAccount) {
-        ArrayList<FeatureItem> featuresList = new ArrayList<>();
+    static public List<FeatureItem> get(boolean isMultiAccount) {
+        List<FeatureItem> featuresList = new ArrayList<>();
         // Basic features showed on first install
         featuresList.add(new FeatureItem(R.drawable.whats_new_files,
                 R.string.welcome_feature_1_title, R.string.welcome_feature_1_text,

src/main/java/com/owncloud/android/files/services/FileDownloader.java

@@ -91,13 +91,13 @@ public class FileDownloader extends Service
     private Looper mServiceLooper;
     private ServiceHandler mServiceHandler;
     private IBinder mBinder;
-    private OwnCloudClient mDownloadClient = null;
-    private Account mCurrentAccount = null;
+    private OwnCloudClient mDownloadClient;
+    private Account mCurrentAccount;
     private FileDataStorageManager mStorageManager;
 
     private IndexedForest<DownloadFileOperation> mPendingDownloads = new IndexedForest<>();
 
-    private DownloadFileOperation mCurrentDownload = null;
+    private DownloadFileOperation mCurrentDownload;
 
     private NotificationManager mNotificationManager;
     private NotificationCompat.Builder mNotificationBuilder;
@@ -221,11 +221,11 @@ public class FileDownloader extends Service
     /**
      * Provides a binder object that clients can use to perform operations on the queue of downloads,
      * excepting the addition of new files.
-     * <p/>
+     *
      * Implemented to perform cancellation, pause and resume of existing downloads.
      */
     @Override
-    public IBinder onBind(Intent arg0) {
+    public IBinder onBind(Intent intent) {
         return mBinder;
     }
 
@@ -501,7 +501,7 @@ public class FileDownloader extends Service
         file.setEtag(mCurrentDownload.getEtag());
         file.setMimetype(mCurrentDownload.getMimeType());
         file.setStoragePath(mCurrentDownload.getSavePath());
-        file.setFileLength((new File(mCurrentDownload.getSavePath()).length()));
+        file.setFileLength(new File(mCurrentDownload.getSavePath()).length());
         file.setRemoteId(mCurrentDownload.getFile().getRemoteId());
         mStorageManager.saveFile(file);
         FileDataStorageManager.triggerMediaScan(file.getStoragePath());
@@ -602,8 +602,8 @@ public class FileDownloader extends Service
             int tickerId = (downloadResult.isSuccess()) ? R.string.downloader_download_succeeded_ticker :
                     R.string.downloader_download_failed_ticker;
 
-            boolean needsToUpdateCredentials = (ResultCode.UNAUTHORIZED.equals(downloadResult.getCode()));
-            tickerId = (needsToUpdateCredentials) ?
+            boolean needsToUpdateCredentials = ResultCode.UNAUTHORIZED.equals(downloadResult.getCode());
+            tickerId = needsToUpdateCredentials ?
                     R.string.downloader_download_failed_credentials_error : tickerId;
 
             mNotificationBuilder

src/main/java/com/owncloud/android/files/services/FileUploader.java

@@ -169,18 +169,18 @@ public class FileUploader extends Service
     private Looper mServiceLooper;
     private ServiceHandler mServiceHandler;
     private IBinder mBinder;
-    private OwnCloudClient mUploadClient = null;
-    private Account mCurrentAccount = null;
+    private OwnCloudClient mUploadClient;
+    private Account mCurrentAccount;
     private FileDataStorageManager mStorageManager;
     //since there can be only one instance of an Android service, there also just one db connection.
-    private UploadsStorageManager mUploadsStorageManager = null;
+    private UploadsStorageManager mUploadsStorageManager;
 
-    private IndexedForest<UploadFileOperation> mPendingUploads = new IndexedForest<UploadFileOperation>();
+    private IndexedForest<UploadFileOperation> mPendingUploads = new IndexedForest<>();
 
     /**
      * {@link UploadFileOperation} object of ongoing upload. Can be null. Note: There can only be one concurrent upload!
      */
-    private UploadFileOperation mCurrentUpload = null;
+    private UploadFileOperation mCurrentUpload;
 
     private NotificationManager mNotificationManager;
     private NotificationCompat.Builder mNotificationBuilder;
@@ -736,7 +736,7 @@ public class FileUploader extends Service
      * uploads.
      */
     @Override
-    public IBinder onBind(Intent arg0) {
+    public IBinder onBind(Intent intent) {
         return mBinder;
     }
 
@@ -865,17 +865,17 @@ public class FileUploader extends Service
             if (account == null || file == null) {
                 return false;
             }
-            return (mPendingUploads.contains(account.name, file.getRemotePath()));
+            return mPendingUploads.contains(account.name, file.getRemotePath());
         }
 
         public boolean isUploadingNow(OCUpload upload) {
-            return (
+            return
                     upload != null &&
                             mCurrentAccount != null &&
                             mCurrentUpload != null &&
                             upload.getAccountName().equals(mCurrentAccount.name) &&
                             upload.getRemotePath().equals(mCurrentUpload.getRemotePath())
-            );
+            ;
         }
 
         /**

src/main/java/com/owncloud/android/files/services/IndexedForest.java

@@ -45,10 +45,10 @@ public class IndexedForest<V> {
 
     @SuppressWarnings("PMD.ShortClassName")
     private class Node<V> {
-        private String mKey = null;
-        private Node<V> mParent = null;
+        private String mKey;
+        private Node<V> mParent;
         private Set<Node<V>> mChildren = new HashSet<>();    // TODO be careful with hash()
-        private V mPayload = null;
+        private V mPayload;
 
         // payload is optional
         public Node(String key, V payload) {
@@ -113,8 +113,8 @@ public class IndexedForest<V> {
         } else {
             // value really added
             String currentPath = remotePath;
-            String parentPath = null;
-            String parentKey = null;
+            String parentPath;
+            String parentKey;
             Node<V> currentNode = valuedNode;
             Node<V> parentNode = null;
             boolean linked = false;
@@ -142,7 +142,7 @@ public class IndexedForest<V> {
                 linkedTo = parentNode.getKey().substring(accountName.length());
             }
 
-            return new Pair<String, String>(targetKey, linkedTo);
+            return new Pair<>(targetKey, linkedTo);
         }
     }
 
@@ -156,7 +156,7 @@ public class IndexedForest<V> {
                 return remove(accountName, remotePath);
             }
         }
-        return new Pair<V, String>(null, null);
+        return new Pair<>(null, null);
     }
 
 
@@ -186,10 +186,10 @@ public class IndexedForest<V> {
                 unlinkedFrom = parent.getKey().substring(accountName.length());
             }
 
-            return new Pair<V, String>(firstRemoved.getPayload(), unlinkedFrom);
+            return new Pair<>(firstRemoved.getPayload(), unlinkedFrom);
         }
 
-        return new Pair<V, String>(null, null);
+        return new Pair<>(null, null);
     }
 
     private void removeDescendants(Node<V> removed) {
@@ -246,5 +246,4 @@ public class IndexedForest<V> {
     private String buildKey(String accountName, String remotePath) {
         return accountName + remotePath;
     }
-
 }

src/main/java/com/owncloud/android/media/MediaServiceBinder.java

@@ -43,7 +43,7 @@ public class MediaServiceBinder extends Binder implements MediaController.MediaP
     /**
      * {@link MediaService} instance to access with the binder
      */
-    private MediaService mService = null;
+    private MediaService mService;
 
     /**
      * Public constructor

src/main/java/com/owncloud/android/operations/CheckCurrentCredentialsOperation.java

@@ -36,7 +36,7 @@ import java.util.ArrayList;
  */
 public class CheckCurrentCredentialsOperation extends SyncOperation {
 
-    private Account mAccount = null;
+    private Account mAccount;
 
     public CheckCurrentCredentialsOperation(Account account) {
         if (account == null) {
@@ -55,7 +55,7 @@ public class CheckCurrentCredentialsOperation extends SyncOperation {
         } else {
             RemoteOperation check = new ExistenceCheckRemoteOperation(OCFile.ROOT_PATH, false);
             result = check.execute(client);
-            ArrayList<Object> data = new ArrayList<Object>();
+            ArrayList<Object> data = new ArrayList<>();
             data.add(mAccount);
             result.setData(data);
         }

src/main/java/com/owncloud/android/operations/DownloadFileOperation.java

@@ -56,8 +56,8 @@ public class DownloadFileOperation extends RemoteOperation {
     private OCFile mFile;
     private String mBehaviour;
     private Context mContext;
-    private Set<OnDatatransferProgressListener> mDataTransferListeners = new HashSet<OnDatatransferProgressListener>();
-    private long mModificationTimestamp = 0;
+    private Set<OnDatatransferProgressListener> mDataTransferListeners = new HashSet<>();
+    private long mModificationTimestamp;
     private String mEtag = "";
     private final AtomicBoolean mCancellationRequested = new AtomicBoolean(false);
     

src/main/java/com/owncloud/android/operations/RefreshFolderOperation.java

@@ -330,9 +330,7 @@ public class RefreshFolderOperation extends RemoteOperation {
             mStorageManager.removeFolder(
                     mLocalFolder,
                     true,
-                    (mLocalFolder.isDown() &&
-                            mLocalFolder.getStoragePath().startsWith(currentSavePath)
-                    )
+                    mLocalFolder.isDown() && mLocalFolder.getStoragePath().startsWith(currentSavePath)
             );
         }
     }

src/main/java/com/owncloud/android/operations/SynchronizeFolderOperation.java

@@ -42,7 +42,6 @@ import com.owncloud.android.utils.FileStorageUtils;
 import com.owncloud.android.utils.MimeTypeUtil;
 
 import java.io.File;
-import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -261,7 +260,7 @@ public class SynchronizeFolderOperation extends SyncOperation {
      *
      * @param folderAndFiles Remote folder and children files in Folder
      */
-    private void synchronizeData(ArrayList<Object> folderAndFiles) throws OperationCancelledException {
+    private void synchronizeData(List<Object> folderAndFiles) throws OperationCancelledException {
         FileDataStorageManager storageManager = getStorageManager();
         
         // parse data from remote folder

src/main/java/com/owncloud/android/operations/UnshareOperation.java

@@ -34,7 +34,7 @@ import com.owncloud.android.lib.resources.shares.RemoveRemoteShareOperation;
 import com.owncloud.android.lib.resources.shares.ShareType;
 import com.owncloud.android.operations.common.SyncOperation;
 
-import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Unshare file/folder
@@ -80,7 +80,7 @@ public class UnshareOperation extends SyncOperation {
                 } else if (ShareType.USER.equals(mShareType) || ShareType.GROUP.equals(mShareType)
                     || ShareType.FEDERATED.equals(mShareType)){
                     // Check if it is the last share
-                    ArrayList <OCShare> sharesWith = getStorageManager().
+                    List <OCShare> sharesWith = getStorageManager().
                             getSharesWithForAFile(mRemotePath,
                             getStorageManager().getAccount().name);
                     if (sharesWith.size() == 1) {

src/main/java/com/owncloud/android/operations/UploadFileOperation.java

@@ -25,6 +25,7 @@ import android.content.Context;
 import android.net.Uri;
 import android.os.Build;
 import android.support.annotation.RequiresApi;
+import android.util.Log;
 
 import com.evernote.android.job.JobRequest;
 import com.evernote.android.job.util.Device;
@@ -111,18 +112,18 @@ public class UploadFileOperation extends SyncOperation {
      * (if forceOverwrite==false and remote file already exists).
      */
     private OCFile mOldFile;
-    private String mRemotePath = null;
+    private String mRemotePath;
     private String mFolderUnlockToken;
-    private boolean mRemoteFolderToBeCreated = false;
-    private boolean mForceOverwrite = false;
+    private boolean mRemoteFolderToBeCreated;
+    private boolean mForceOverwrite;
     private int mLocalBehaviour = FileUploader.LOCAL_BEHAVIOUR_COPY;
     private int mCreatedBy = CREATED_BY_USER;
-    private boolean mOnWifiOnly = false;
-    private boolean mWhileChargingOnly = false;
-    private boolean mIgnoringPowerSaveMode = false;
+    private boolean mOnWifiOnly;
+    private boolean mWhileChargingOnly;
+    private boolean mIgnoringPowerSaveMode;
 
-    private boolean mWasRenamed = false;
-    private long mOCUploadId = -1;
+    private boolean mWasRenamed;
+    private long mOCUploadId;
     /**
      * Local path to file which is to be uploaded (before any possible renaming or moving).
      */
@@ -976,7 +977,7 @@ public class UploadFileOperation extends SyncOperation {
                 try {
                     move(originalFile, newFile);
                 } catch (IOException e) {
-                    e.printStackTrace();
+                    Log.e(TAG, "Error moving file", e);
                 }
                 getStorageManager().deleteFileInMediaScan(originalFile.getAbsolutePath());
                 mFile.setStoragePath(newFile.getAbsolutePath());

src/main/java/com/owncloud/android/providers/DocumentsStorageProvider.java

@@ -57,7 +57,9 @@ import org.nextcloud.providers.cursors.RootCursor;
 
 import java.io.File;
 import java.io.FileNotFoundException;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Vector;
 
@@ -66,7 +68,7 @@ public class DocumentsStorageProvider extends DocumentsProvider {
 
     private static final String TAG = "DocumentsStorageProvider";
 
-    private FileDataStorageManager mCurrentStorageManager = null;
+    private FileDataStorageManager mCurrentStorageManager;
     private static Map<Long, FileDataStorageManager> mRootIdToStorageManager;
 
     @Override
@@ -291,8 +293,8 @@ public class DocumentsStorageProvider extends DocumentsProvider {
         return !(cancellationSignal != null && cancellationSignal.isCanceled());
     }
 
-    Vector<OCFile> findFiles(OCFile root, String query) {
-        Vector<OCFile> result = new Vector<>();
+    List<OCFile> findFiles(OCFile root, String query) {
+        List<OCFile> result = new ArrayList<>();
         for (OCFile f : mCurrentStorageManager.getFolderContent(root, false)) {
             if (f.isFolder()) {
                 result.addAll(findFiles(f, query));

src/main/java/com/owncloud/android/services/OperationsService.java

@@ -138,9 +138,9 @@ public class OperationsService extends Service {
             mUndispatchedFinishedOperations = new ConcurrentHashMap<>();
 
     private static class Target {
-        public Uri mServerUrl = null;
-        public Account mAccount = null;
-        public String mCookie = null;
+        public Uri mServerUrl;
+        public Account mAccount;
+        public String mCookie;
 
         public Target(Account account, Uri serverUrl, String cookie) {
             mAccount = account;

src/main/java/com/owncloud/android/services/SyncFolderHandler.java

@@ -55,7 +55,7 @@ class SyncFolderHandler extends Handler {
 
     private IndexedForest<SynchronizeFolderOperation> mPendingOperations = new IndexedForest<>();
 
-    private Account mCurrentAccount = null;
+    private Account mCurrentAccount;
     private FileDataStorageManager mStorageManager;
     private SynchronizeFolderOperation mCurrentSyncOperation;
 

src/main/java/com/owncloud/android/syncadapter/AbstractOwnCloudSyncAdapter.java

@@ -52,7 +52,7 @@ public abstract class AbstractOwnCloudSyncAdapter extends
     private ContentProviderClient mContentProviderClient;
     private FileDataStorageManager mStoreManager;
 
-    private OwnCloudClient mClient = null;
+    private OwnCloudClient mClient;
 
     public AbstractOwnCloudSyncAdapter(Context context, boolean autoInitialize) {
         super(context, autoInitialize);

src/main/java/com/owncloud/android/syncadapter/FileSyncService.java

@@ -33,7 +33,7 @@ import android.os.IBinder;
 public class FileSyncService extends Service {
     
     // Storage for an instance of the sync adapter
-    private static FileSyncAdapter sSyncAdapter = null;
+    private static FileSyncAdapter sSyncAdapter;
     // Object to use as a thread-safe lock
     private static final Object sSyncAdapterLock = new Object();
     

src/main/java/com/owncloud/android/ui/CustomPopup.java

@@ -39,7 +39,7 @@ public class CustomPopup {
     protected final View mAnchor;
     protected final PopupWindow mWindow;
     private View root;
-    private Drawable background = null;
+    private Drawable background;
     protected final WindowManager mWManager;
 
     public CustomPopup(View anchor) {
@@ -57,8 +57,7 @@ public class CustomPopup {
             }
         });
 
-        mWManager = (WindowManager) anchor.getContext().getSystemService(
-                Context.WINDOW_SERVICE);
+        mWManager = (WindowManager) anchor.getContext().getSystemService(Context.WINDOW_SERVICE);
         onCreate();
     }
 

src/main/java/com/owncloud/android/ui/EmptyRecyclerView.java

@@ -31,10 +31,9 @@ import android.view.View;
  * Extends RecyclerView to show a custom view if no data is available
  * Inspired by http://alexzh.com/tutorials/how-to-setemptyview-to-recyclerview
  */
-
 public class EmptyRecyclerView extends RecyclerView {
     private View mEmptyView;
-    private boolean hasFooter = false;
+    private boolean hasFooter;
 
     public EmptyRecyclerView(Context context) {
         super(context);

src/main/java/com/owncloud/android/ui/activities/ActivitiesPresenter.java

@@ -35,7 +35,7 @@ public class ActivitiesPresenter implements ActivitiesContract.ActionListener {
     private final ActivitiesContract.View activitiesView;
     private final ActivitiesRepository activitiesRepository;
     private final FilesRepository filesRepository;
-    private boolean activityStopped = false;
+    private boolean activityStopped;
 
 
     ActivitiesPresenter(@NonNull ActivitiesRepository activitiesRepository,

src/main/java/com/owncloud/android/ui/activity/BaseActivity.java

@@ -36,7 +36,7 @@ public abstract class BaseActivity extends AppCompatActivity {
     /**
      * Flag to signal that the activity will is finishing to enforce the creation of an ownCloud {@link Account}.
      */
-    private boolean mRedirectingToSetupAccount = false;
+    private boolean mRedirectingToSetupAccount;
 
     /**
      * Flag to signal when the value of mAccount was set.
@@ -51,7 +51,7 @@ public abstract class BaseActivity extends AppCompatActivity {
     /**
      * Access point to the cached database for the current ownCloud {@link Account}.
      */
-    private FileDataStorageManager mStorageManager = null;
+    private FileDataStorageManager mStorageManager;
 
     @Override
     protected void onNewIntent (Intent intent) {
@@ -91,12 +91,11 @@ public abstract class BaseActivity extends AppCompatActivity {
     protected void setAccount(Account account, boolean savedAccount) {
         Account oldAccount = mCurrentAccount;
         boolean validAccount =
-                (account != null && AccountUtils.setCurrentOwnCloudAccount(getApplicationContext(),
-                        account.name));
+                account != null && AccountUtils.setCurrentOwnCloudAccount(getApplicationContext(), account.name);
         if (validAccount) {
             mCurrentAccount = account;
             mAccountWasSet = true;
-            mAccountWasRestored = (savedAccount || mCurrentAccount.equals(oldAccount));
+            mAccountWasRestored = savedAccount || mCurrentAccount.equals(oldAccount);
 
         } else {
             swapToDefaultAccount();
@@ -123,7 +122,7 @@ public abstract class BaseActivity extends AppCompatActivity {
 
         } else {
             mAccountWasSet = true;
-            mAccountWasRestored = (newAccount.equals(mCurrentAccount));
+            mAccountWasRestored = newAccount.equals(mCurrentAccount);
             mCurrentAccount = newAccount;
         }
     }

src/main/java/com/owncloud/android/ui/activity/DrawerActivity.java

@@ -99,6 +99,7 @@ import org.greenrobot.eventbus.Subscribe;
 import org.greenrobot.eventbus.ThreadMode;
 
 import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Base class to handle setup of the drawer implementation including user switching and avatar fetching and fallback
@@ -824,7 +825,7 @@ public abstract class DrawerActivity extends ToolbarActivity implements DisplayU
     private void updateQuotaLink() {
         if (mQuotaTextLink != null) {
             if (getBaseContext().getResources().getBoolean(R.bool.show_external_links)) {
-                ArrayList<ExternalLink> quotas = externalLinksProvider.getExternalLink(ExternalLinkType.QUOTA);
+                List<ExternalLink> quotas = externalLinksProvider.getExternalLink(ExternalLinkType.QUOTA);
 
                 float density = getResources().getDisplayMetrics().density;
                 final int size = Math.round(24 * density);

src/main/java/com/owncloud/android/ui/activity/ErrorsWhileCopyingHandlerActivity.java

@@ -48,7 +48,7 @@ import com.owncloud.android.utils.DisplayUtils;
 import com.owncloud.android.utils.FileStorageUtils;
 
 import java.io.File;
-import java.util.ArrayList;
+import java.util.List;
 
 
 /**
@@ -75,8 +75,8 @@ public class ErrorsWhileCopyingHandlerActivity  extends AppCompatActivity implem
     
     protected Account mAccount;
     protected FileDataStorageManager mStorageManager;
-    protected ArrayList<String> mLocalPaths;
-    protected ArrayList<String> mRemotePaths;
+    protected List<String> mLocalPaths;
+    protected List<String> mRemotePaths;
     protected ArrayAdapter<String> mAdapter;
     protected Handler mHandler;
     private DialogFragment mCurrentDialog;

src/main/java/com/owncloud/android/ui/activity/ExternalSiteWebView.java

@@ -53,7 +53,7 @@ public class ExternalSiteWebView extends FileActivity {
 
     private static final String TAG = ExternalSiteWebView.class.getSimpleName();
 
-    private boolean showSidebar = false;
+    private boolean showSidebar;
     private int menuItemId;
     private WebView webview;
 

src/main/java/com/owncloud/android/ui/activity/FileActivity.java

@@ -118,15 +118,16 @@ public abstract class FileActivity extends DrawerActivity
 
     private FileOperationsHelper mFileOperationsHelper;
 
-    private ServiceConnection mOperationsServiceConnection = null;
+    private ServiceConnection mOperationsServiceConnection;
 
-    private OperationsServiceBinder mOperationsServiceBinder = null;
+    private OperationsServiceBinder mOperationsServiceBinder;
 
-    private boolean mResumed = false;
+    private boolean mResumed;
 
-    protected FileDownloaderBinder mDownloaderBinder = null;
-    protected FileUploaderBinder mUploaderBinder = null;
-    private ServiceConnection mDownloadServiceConnection, mUploadServiceConnection = null;
+    protected FileDownloaderBinder mDownloaderBinder;
+    protected FileUploaderBinder mUploaderBinder;
+    private ServiceConnection mDownloadServiceConnection;
+    private ServiceConnection mUploadServiceConnection;
 
 
 

src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.java

@@ -158,7 +158,7 @@ public class FileDisplayActivity extends HookActivity
     private SyncBroadcastReceiver mSyncBroadcastReceiver;
     private UploadFinishReceiver mUploadFinishReceiver;
     private DownloadFinishReceiver mDownloadFinishReceiver;
-    private RemoteOperationResult mLastSslUntrustedServerResult = null;
+    private RemoteOperationResult mLastSslUntrustedServerResult;
 
     private boolean mDualPane;
     private View mLeftFragmentContainer;
@@ -192,14 +192,14 @@ public class FileDisplayActivity extends HookActivity
 
     private OCFile mWaitingToPreview;
 
-    private boolean mSyncInProgress = false;
+    private boolean mSyncInProgress;
 
     private OCFile mWaitingToSend;
 
     private Collection<MenuItem> mDrawerMenuItemstoShowHideList;
 
-    private MediaServiceBinder mMediaServiceBinder =  null;
-    private MediaServiceConnection mMediaServiceConnection = null;
+    private MediaServiceBinder mMediaServiceBinder;
+    private MediaServiceConnection mMediaServiceConnection;
 
     private String searchQuery;
 
@@ -580,11 +580,11 @@ public class FileDisplayActivity extends HookActivity
             return OCShare.READ_PERMISSION_FLAG;    // minimum permissions
 
         } else if (isFederated) {
-            return (getFile().isFolder() ? OCShare.FEDERATED_PERMISSIONS_FOR_FOLDER_AFTER_OC9 :
-                    OCShare.FEDERATED_PERMISSIONS_FOR_FILE_AFTER_OC9);
+            return getFile().isFolder() ? OCShare.FEDERATED_PERMISSIONS_FOR_FOLDER_AFTER_OC9 :
+                    OCShare.FEDERATED_PERMISSIONS_FOR_FILE_AFTER_OC9;
         } else {
-            return (getFile().isFolder() ? OCShare.MAXIMUM_PERMISSIONS_FOR_FOLDER :
-                    OCShare.MAXIMUM_PERMISSIONS_FOR_FILE);
+            return getFile().isFolder() ? OCShare.MAXIMUM_PERMISSIONS_FOR_FOLDER :
+                    OCShare.MAXIMUM_PERMISSIONS_FOR_FILE;
         }
     }
 
@@ -1570,8 +1570,7 @@ public class FileDisplayActivity extends HookActivity
 
         private boolean isSameAccount(Intent intent) {
             String accountName = intent.getStringExtra(FileDownloader.ACCOUNT_NAME);
-            return (accountName != null && getAccount() != null &&
-                    accountName.equals(getAccount().name));
+            return accountName != null && getAccount() != null && accountName.equals(getAccount().name);
         }
     }
 

src/main/java/com/owncloud/android/ui/activity/FolderPickerActivity.java

@@ -78,10 +78,10 @@ public class FolderPickerActivity extends FileActivity implements FileFragment.C
 
     private static final String TAG_LIST_OF_FOLDERS = "LIST_OF_FOLDERS";
        
-    private boolean mSyncInProgress = false;
+    private boolean mSyncInProgress;
 
-    private boolean mSearchOnlyFolders = false;
-    private boolean mDoNotEnterEncryptedFolder = false;
+    private boolean mSearchOnlyFolders;
+    private boolean mDoNotEnterEncryptedFolder;
 
     protected Button mCancelBtn;
     protected Button mChooseBtn;
@@ -470,8 +470,8 @@ public class FolderPickerActivity extends FileActivity implements FileFragment.C
                 String syncFolderRemotePath = intent.getStringExtra(FileSyncAdapter.EXTRA_FOLDER_PATH);
                 RemoteOperationResult syncResult = (RemoteOperationResult)
                         DataHolderUtil.getInstance().retrieve(intent.getStringExtra(FileSyncAdapter.EXTRA_RESULT));
-                boolean sameAccount = (getAccount() != null && accountName.equals(getAccount().name)
-                        && getStorageManager() != null); 
+                boolean sameAccount = getAccount() != null && accountName.equals(getAccount().name)
+                        && getStorageManager() != null;
     
                 if (sameAccount) {
                     if (FileSyncAdapter.EVENT_FULL_SYNC_START.equals(event)) {

src/main/java/com/owncloud/android/ui/activity/LogHistoryActivity.java

@@ -62,7 +62,7 @@ public class LogHistoryActivity extends ToolbarActivity {
     private static final String DIALOG_WAIT_TAG = "DIALOG_WAIT";
 
     private String mLogPath = Log_OC.getLogPath();
-    private File logDIR = null;
+    private File logDIR;
     private String mLogText;
 
 

src/main/java/com/owncloud/android/ui/activity/ManageAccountsActivity.java

@@ -65,6 +65,7 @@ import org.parceler.Parcels;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Set;
 
 /**
@@ -87,7 +88,8 @@ public class ManageAccountsActivity extends FileActivity
     private final Handler mHandler = new Handler();
     private String mAccountName;
     private AccountListAdapter mAccountListAdapter;
-    private ServiceConnection mDownloadServiceConnection, mUploadServiceConnection = null;
+    private ServiceConnection mDownloadServiceConnection;
+    private ServiceConnection mUploadServiceConnection;
     Set<String> mOriginalAccounts;
     String mOriginalCurrentAccount;
     private Drawable mTintedCheck;
@@ -237,9 +239,9 @@ public class ManageAccountsActivity extends FileActivity
      *
      * @return list of account list items
      */
-    private ArrayList<AccountListItem> getAccountListItems() {
+    private List<AccountListItem> getAccountListItems() {
         Account[] accountList = AccountManager.get(this).getAccountsByType(MainApp.getAccountType(this));
-        ArrayList<AccountListItem> adapterAccountList = new ArrayList<>(accountList.length);
+        List<AccountListItem> adapterAccountList = new ArrayList<>(accountList.length);
         for (Account account : accountList) {
             boolean pendingForRemoval = arbitraryDataProvider.getBooleanValue(account, PENDING_FOR_REMOVAL);
             adapterAccountList.add(new AccountListItem(account, !pendingForRemoval));
@@ -307,7 +309,7 @@ public class ManageAccountsActivity extends FileActivity
 
     @Subscribe(threadMode = ThreadMode.MAIN)
     public void onAccountRemovedEvent(AccountRemovedEvent event) {
-        ArrayList<AccountListItem> accountListItemArray = getAccountListItems();
+        List<AccountListItem> accountListItemArray = getAccountListItems();
         mAccountListAdapter.clear();
         mAccountListAdapter.addAll(accountListItemArray);
         mAccountListAdapter.notifyDataSetChanged();
@@ -337,7 +339,7 @@ public class ManageAccountsActivity extends FileActivity
                 AccountUtils.setCurrentOwnCloudAccount(this, accountName);
             }
 
-            ArrayList<AccountListItem> accountListItemArray = getAccountListItems();
+            List<AccountListItem> accountListItemArray = getAccountListItems();
             if (accountListItemArray.size() > 1) {
                 mAccountListAdapter = new AccountListAdapter(this, accountListItemArray, mTintedCheck);
                 mListView.setAdapter(mAccountListAdapter);

src/main/java/com/owncloud/android/ui/activity/NotificationsActivity.java

@@ -104,7 +104,7 @@ public class NotificationsActivity extends FileActivity {
     private Unbinder unbinder;
 
     private NotificationListAdapter adapter;
-    private Snackbar snackbar = null;
+    private Snackbar snackbar;
     private OwnCloudClient client;
     private Account currentAccount;
 

src/main/java/com/owncloud/android/ui/activity/PassCodeActivity.java

@@ -46,7 +46,7 @@ import com.owncloud.android.utils.ThemeUtils;
 
 import java.util.Arrays;
 
-public class PassCodeActivity extends AppCompatActivity {
+public class    PassCodeActivity extends AppCompatActivity {
 
     private static final String TAG = PassCodeActivity.class.getSimpleName();
 
@@ -70,7 +70,7 @@ public class PassCodeActivity extends AppCompatActivity {
 
     private String [] mPassCodeDigits = {"","","",""};
     private static final String KEY_PASSCODE_DIGITS = "PASSCODE_DIGITS";
-    private boolean mConfirmingPassCode = false;
+    private boolean mConfirmingPassCode;
     private static final String KEY_CONFIRMING_PASSCODE = "CONFIRMING_PASSCODE";
 
     private boolean mBChange = true; // to control that only one blocks jump

src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java

@@ -134,19 +134,19 @@ public class ReceiveExternalFilesActivity extends FileActivity
 
     private AccountManager mAccountManager;
     private Stack<String> mParents = new Stack<>();
-    private ArrayList<Parcelable> mStreamsToUpload;
+    private List<Parcelable> mStreamsToUpload;
     private String mUploadPath;
     private OCFile mFile;
 
     private SyncBroadcastReceiver mSyncBroadcastReceiver;
-    private boolean mSyncInProgress = false;
+    private boolean mSyncInProgress;
 
     private final static int REQUEST_CODE__SETUP_ACCOUNT = REQUEST_CODE__LAST_SHARED + 1;
 
     private final static String KEY_PARENTS = "PARENTS";
     private final static String KEY_FILE = "FILE";
 
-    private boolean mUploadFromTmpFile = false;
+    private boolean mUploadFromTmpFile;
     private String mSubjectText;
     private String mExtraText;
 

src/main/java/com/owncloud/android/ui/activity/UploadFilesActivity.java

@@ -218,7 +218,7 @@ public class UploadFilesActivity extends FileActivity implements
      */
     public static void startUploadActivityForResult(Activity activity, Account account, int requestCode) {
         Intent action = new Intent(activity, UploadFilesActivity.class);
-        action.putExtra(EXTRA_ACCOUNT, (account));
+        action.putExtra(EXTRA_ACCOUNT, account);
         activity.startActivityForResult(action, requestCode);
     }
 

src/main/java/com/owncloud/android/ui/adapter/ActivityAndVersionListAdapter.java

@@ -19,9 +19,9 @@ import com.owncloud.android.ui.interfaces.ActivityListInterface;
 import com.owncloud.android.ui.interfaces.VersionListInterface;
 import com.owncloud.android.utils.DisplayUtils;
 
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
+import java.util.List;
 
 import butterknife.BindView;
 import butterknife.ButterKnife;
@@ -39,7 +39,7 @@ public class ActivityAndVersionListAdapter extends ActivityListAdapter {
         this.versionListInterface = versionListInterface;
     }
 
-    public void setActivityAndVersionItems(ArrayList<Object> items, OwnCloudClient newClient, boolean clear) {
+    public void setActivityAndVersionItems(List<Object> items, OwnCloudClient newClient, boolean clear) {
         if (client == null) {
             client = newClient;
         }

src/main/java/com/owncloud/android/ui/adapter/ActivityListAdapter.java

@@ -330,7 +330,7 @@ public class ActivityListAdapter extends RecyclerView.Adapter<RecyclerView.ViewH
         return ssb;
     }
 
-    private RichObject searchObjectByName(ArrayList<RichObject> richObjectList, String name) {
+    private RichObject searchObjectByName(List<RichObject> richObjectList, String name) {
         for (RichObject richObject : richObjectList) {
             if (richObject.getTag().equalsIgnoreCase(name))
                 return richObject;

src/main/java/com/owncloud/android/ui/adapter/CertificateCombinedExceptionViewAdapter.java

@@ -21,7 +21,6 @@
 package com.owncloud.android.ui.adapter;
 
 import android.view.View;
-import android.widget.TextView;
 
 import com.owncloud.android.R;
 import com.owncloud.android.lib.common.network.CertificateCombinedException;
@@ -29,13 +28,12 @@ import com.owncloud.android.ui.dialog.SslUntrustedCertDialog;
 
 /**
  * TODO
- *
  */
 public class CertificateCombinedExceptionViewAdapter implements SslUntrustedCertDialog.ErrorViewAdapter {
     
     //private final static String TAG = CertificateCombinedExceptionViewAdapter.class.getSimpleName();
     
-    private CertificateCombinedException mSslException = null;
+    private CertificateCombinedException mSslException;
     
     public CertificateCombinedExceptionViewAdapter(CertificateCombinedException sslException) {
         mSslException = sslException;
@@ -48,25 +46,25 @@ public class CertificateCombinedExceptionViewAdapter implements SslUntrustedCert
        
         /// refresh
         if (mSslException.getCertPathValidatorException() != null) {
-            ((TextView)dialogView.findViewById(R.id.reason_cert_not_trusted)).setVisibility(View.VISIBLE);
+            dialogView.findViewById(R.id.reason_cert_not_trusted).setVisibility(View.VISIBLE);
         } else {
             dialogView.findViewById(R.id.reason_cert_not_trusted).setVisibility(View.GONE);
         }
         
         if (mSslException.getCertificateExpiredException() != null) {
-            ((TextView)dialogView.findViewById(R.id.reason_cert_expired)).setVisibility(View.VISIBLE);
+            dialogView.findViewById(R.id.reason_cert_expired).setVisibility(View.VISIBLE);
         } else {
             dialogView.findViewById(R.id.reason_cert_expired).setVisibility(View.GONE);
         }
         
         if (mSslException.getCertificateNotYetValidException() != null) {
-            ((TextView)dialogView.findViewById(R.id.reason_cert_not_yet_valid)).setVisibility(View.VISIBLE);
+            dialogView.findViewById(R.id.reason_cert_not_yet_valid).setVisibility(View.VISIBLE);
         } else {
             dialogView.findViewById(R.id.reason_cert_not_yet_valid).setVisibility(View.GONE);
         }
 
         if (mSslException.getSslPeerUnverifiedException() != null) {
-            ((TextView)dialogView.findViewById(R.id.reason_hostname_not_verified)).setVisibility(View.VISIBLE);
+            dialogView.findViewById(R.id.reason_hostname_not_verified).setVisibility(View.VISIBLE);
         } else {
             dialogView.findViewById(R.id.reason_hostname_not_verified).setVisibility(View.GONE);
         }

src/main/java/com/owncloud/android/ui/adapter/OCFileListAdapter.java

@@ -75,6 +75,7 @@ import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 import java.util.Vector;
 
 /**
@@ -91,8 +92,8 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
     private List<OCFile> mFilesAll = new ArrayList<>();
     private boolean mHideItemOptions;
     private boolean gridView;
-    private boolean multiSelect = false;
-    private HashSet<OCFile> checkedFiles;
+    private boolean multiSelect;
+    private Set<OCFile> checkedFiles;
 
     private FileDataStorageManager mStorageManager;
     private Account mAccount;
@@ -106,7 +107,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
     private static final int VIEWTYPE_ITEM = 1;
     private static final int VIEWTYPE_IMAGE = 2;
 
-    private ArrayList<ThumbnailsCacheManager.ThumbnailGenerationTask> asyncTasks = new ArrayList<>();
+    private List<ThumbnailsCacheManager.ThumbnailGenerationTask> asyncTasks = new ArrayList<>();
 
     public OCFileListAdapter(Context context, ComponentsGetter transferServiceGetter,
                              OCFileListFragmentInterface ocFileListFragmentInterface, boolean argHideItemOptions,
@@ -532,7 +533,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
         }
     }
 
-    public void setData(ArrayList<Object> objects, ExtendedListFragment.SearchType searchType,
+    public void setData(List<Object> objects, ExtendedListFragment.SearchType searchType,
                         FileDataStorageManager storageManager, OCFile folder) {
         if (storageManager != null && mStorageManager == null) {
             mStorageManager = storageManager;
@@ -569,7 +570,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
         });
     }
 
-    private void parseShares(ArrayList<Object> objects) {
+    private void parseShares(List<Object> objects) {
         List<OCShare> shares = new ArrayList<>();
 
         for (Object shareObject : objects) {
@@ -608,7 +609,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
         mStorageManager.saveShares(shares);
     }
 
-    private void parseVirtuals(ArrayList<Object> objects, ExtendedListFragment.SearchType searchType) {
+    private void parseVirtuals(List<Object> objects, ExtendedListFragment.SearchType searchType) {
         VirtualFolderType type;
         boolean onlyImages = false;
         switch (searchType) {
@@ -666,7 +667,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
      * @param files Collection of files to filter
      * @return Folders in the input
      */
-    public List<OCFile> getFolders(ArrayList<OCFile> files) {
+    public List<OCFile> getFolders(List<OCFile> files) {
         List<OCFile> ret = new ArrayList<>();
 
         for (OCFile file : files) {
@@ -685,11 +686,11 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
         notifyDataSetChanged();
     }
 
-    public HashSet<OCFile> getCheckedItems() {
+    public Set<OCFile> getCheckedItems() {
         return checkedFiles;
     }
 
-    public void setCheckedItem(HashSet<OCFile> files) {
+    public void setCheckedItem(Set<OCFile> files) {
         checkedFiles.clear();
         checkedFiles.addAll(files);
     }

src/main/java/com/owncloud/android/ui/adapter/ProgressListener.java

@@ -31,9 +31,9 @@ import java.lang.ref.WeakReference;
  * Progress listener for file transfers.
  */
 public class ProgressListener implements OnDatatransferProgressListener {
-    private int mLastPercent = 0;
-    private OCUpload mUpload = null;
-    private WeakReference<ProgressBar> mProgressBar = null;
+    private int mLastPercent;
+    private OCUpload mUpload;
+    private WeakReference<ProgressBar> mProgressBar;
 
     public ProgressListener(OCUpload upload, ProgressBar progressBar) {
         mUpload = upload;

src/main/java/com/owncloud/android/ui/adapter/ShareUserListAdapter.java

@@ -35,7 +35,7 @@ import com.owncloud.android.lib.resources.shares.ShareType;
 import com.owncloud.android.ui.TextDrawable;
 
 import java.security.NoSuchAlgorithmException;
-import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Adapter to show a user/group in Share With List
@@ -43,11 +43,11 @@ import java.util.ArrayList;
 public class ShareUserListAdapter extends ArrayAdapter {
 
     private Context mContext;
-    private ArrayList<OCShare> mShares;
+    private List<OCShare> mShares;
     private ShareUserAdapterListener mListener;
     private float mAvatarRadiusDimension;
 
-    public ShareUserListAdapter(Context context, int resource, ArrayList<OCShare>shares,
+    public ShareUserListAdapter(Context context, int resource, List<OCShare> shares,
                                 ShareUserAdapterListener listener) {
         super(context, resource);
         mContext= context;

src/main/java/com/owncloud/android/ui/adapter/TrashbinListAdapter.java

@@ -67,7 +67,7 @@ public class TrashbinListAdapter extends RecyclerView.Adapter<RecyclerView.ViewH
     private Account account;
     private FileDataStorageManager storageManager;
 
-    private ArrayList<ThumbnailsCacheManager.ThumbnailGenerationTask> asyncTasks = new ArrayList<>();
+    private List<ThumbnailsCacheManager.ThumbnailGenerationTask> asyncTasks = new ArrayList<>();
 
     public TrashbinListAdapter(TrashbinActivityInterface trashbinActivityInterface,
                                FileDataStorageManager storageManager, Context context) {

src/main/java/com/owncloud/android/ui/adapter/UploadListAdapter.java

@@ -73,7 +73,7 @@ public class UploadListAdapter extends SectionedRecyclerViewAdapter<SectionedVie
 
     private UploadsStorageManager mUploadsStorageManager;
 
-    private UploadGroup[] mUploadGroups = null;
+    private UploadGroup[] mUploadGroups;
 
     @Override
     public int getSectionCount() {

src/main/java/com/owncloud/android/ui/dialog/CredentialsDialogFragment.java

@@ -45,8 +45,8 @@ import com.owncloud.android.authentication.AuthenticatorActivity;
 public class CredentialsDialogFragment extends DialogFragment
     implements DialogInterface.OnClickListener {
 
-    private WebView mWebView = null;
-    private HttpAuthHandler mHandler = null;
+    private WebView mWebView;
+    private HttpAuthHandler mHandler;
 
     private EditText mUsernameET;
     private EditText mPasswordET;

src/main/java/com/owncloud/android/ui/dialog/RenameFileDialogFragment.java

@@ -103,7 +103,7 @@ public class RenameFileDialogFragment
         inputText.setText(currentName);
         int selectionStart = 0;
         int extensionStart = mTargetFile.isFolder() ? -1 : currentName.lastIndexOf('.');
-        int selectionEnd = (extensionStart >= 0) ? extensionStart : currentName.length();
+        int selectionEnd = extensionStart >= 0 ? extensionStart : currentName.length();
         if (selectionStart >= 0 && selectionEnd >= 0) {
             inputText.setSelection(
                     Math.min(selectionStart, selectionEnd),

src/main/java/com/owncloud/android/ui/dialog/SetupEncryptionDialogFragment.java

@@ -55,7 +55,7 @@ import com.owncloud.android.utils.ThemeUtils;
 import java.io.IOException;
 import java.security.KeyPair;
 import java.security.PrivateKey;
-import java.util.ArrayList;
+import java.util.List;
 import java.util.Locale;
 
 /*
@@ -86,7 +86,7 @@ public class SetupEncryptionDialogFragment extends DialogFragment {
     private DownloadKeysAsyncTask task;
     private TextView passwordField;
     private String keyResult;
-    private ArrayList<String> keyWords;
+    private List<String> keyWords;
 
     /**
      * Public factory method to create new SetupEncryptionDialogFragment instance

src/main/java/com/owncloud/android/ui/dialog/SslUntrustedCertDialog.java

@@ -57,12 +57,12 @@ public class SslUntrustedCertDialog extends DialogFragment {
     
     private final static String TAG = SslUntrustedCertDialog.class.getSimpleName();
     
-    protected View mView = null;
-    protected SslErrorHandler mHandler = null;
-    protected X509Certificate m509Certificate = null;
+    protected View mView;
+    protected SslErrorHandler mHandler;
+    protected X509Certificate m509Certificate;
 
-    private ErrorViewAdapter mErrorViewAdapter = null;
-    private CertificateViewAdapter mCertificateViewAdapter = null;
+    private ErrorViewAdapter mErrorViewAdapter;
+    private CertificateViewAdapter mCertificateViewAdapter;
     
     public static SslUntrustedCertDialog newInstanceForEmptySslError(SslError error, SslErrorHandler handler) {
         if (error == null) {

src/main/java/com/owncloud/android/ui/dialog/SyncedFolderPreferencesDialogFragment.java

@@ -65,7 +65,7 @@ public class SyncedFolderPreferencesDialogFragment extends DialogFragment {
     public static final int REQUEST_CODE__SELECT_LOCAL_FOLDER = 1;
     private final static String TAG = SyncedFolderPreferencesDialogFragment.class.getSimpleName();
     private static final String BEHAVIOUR_DIALOG_STATE = "BEHAVIOUR_DIALOG_STATE";
-    protected View mView = null;
+    protected View mView;
     private CharSequence[] mUploadBehaviorItemStrings;
     private SwitchCompat mEnabledSwitch;
     private AppCompatCheckBox mUploadOnWifiCheckbox;

src/main/java/com/owncloud/android/ui/fragment/FileDetailActivitiesFragment.java

@@ -71,6 +71,7 @@ import com.owncloud.android.utils.ThemeUtils;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.List;
 
 import butterknife.BindString;
 import butterknife.BindView;
@@ -307,8 +308,8 @@ public class FileDetailActivitiesFragment extends Fragment implements ActivityLi
                 }
 
                 if (result.isSuccess() && result.getData() != null) {
-                    final ArrayList<Object> data = result.getData();
-                    final ArrayList<Object> activitiesAndVersions = (ArrayList) data.get(0);
+                    final List<Object> data = result.getData();
+                    final List<Object> activitiesAndVersions = (ArrayList) data.get(0);
 
                     if (restoreFileVersionSupported && versions != null) {
                         activitiesAndVersions.addAll(versions);
@@ -351,7 +352,7 @@ public class FileDetailActivitiesFragment extends Fragment implements ActivityLi
         t.start();
     }
 
-    private void populateList(ArrayList<Object> activities, boolean clear) {
+    private void populateList(List<Object> activities, boolean clear) {
         adapter.setActivityAndVersionItems(activities, ownCloudClient, clear);
     }
 

src/main/java/com/owncloud/android/ui/fragment/FileDetailSharingFragment.java

@@ -63,7 +63,7 @@ import com.owncloud.android.ui.fragment.util.SharingMenuHelper;
 import com.owncloud.android.utils.ClipboardUtil;
 import com.owncloud.android.utils.ThemeUtils;
 
-import java.util.ArrayList;
+import java.util.List;
 
 import butterknife.BindView;
 import butterknife.ButterKnife;
@@ -76,7 +76,7 @@ public class FileDetailSharingFragment extends Fragment implements UserListAdapt
     private static final String ARG_ACCOUNT = "ACCOUNT";
 
     // to show share with users/groups info
-    private ArrayList<OCShare> shares;
+    private List<OCShare> shares;
 
     private OCFile file;
     private Account account;

src/main/java/com/owncloud/android/ui/fragment/LocalFileListFragment.java

@@ -49,10 +49,10 @@ public class LocalFileListFragment extends ExtendedListFragment implements Local
     private LocalFileListFragment.ContainerActivity mContainerActivity;
 
     /** Directory to show */
-    private File mDirectory = null;
+    private File mDirectory;
 
     /** Adapter to connect the data from the directory with the View object */
-    private LocalFileListAdapter mAdapter = null;
+    private LocalFileListAdapter mAdapter;
 
     @Override
     public void onCreate(Bundle savedInstanceState) {

src/main/java/com/owncloud/android/ui/fragment/OCFileListFragment.java

@@ -153,7 +153,7 @@ public class OCFileListFragment extends ExtendedListFragment implements
 
     private FileFragment.ContainerActivity mContainerActivity;
 
-    private OCFile mFile = null;
+    private OCFile mFile;
     private OCFileListAdapter mAdapter;
     private boolean mOnlyFoldersClickable;
 
@@ -169,7 +169,7 @@ public class OCFileListFragment extends ExtendedListFragment implements
     private BottomNavigationView bottomNavigationView;
 
     private SearchType currentSearchType;
-    private boolean searchFragment = false;
+    private boolean searchFragment;
     private SearchEvent searchEvent;
     private AsyncTask remoteOperationAsyncTask;
 

src/main/java/com/owncloud/android/ui/fragment/SearchShareesFragment.java

@@ -43,7 +43,7 @@ import com.owncloud.android.lib.resources.shares.OCShare;
 import com.owncloud.android.ui.activity.FileActivity;
 import com.owncloud.android.ui.adapter.ShareUserListAdapter;
 
-import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Fragment for Searching sharees (users and groups)
@@ -69,7 +69,7 @@ public class SearchShareesFragment extends Fragment implements ShareUserListAdap
     private Account mAccount;
 
     // other members
-    private ArrayList<OCShare> mShares;
+    private List<OCShare> mShares;
     private ShareFragmentListener mListener;
 
 

src/main/java/com/owncloud/android/ui/fragment/ShareFileFragment.java

@@ -62,7 +62,7 @@ import com.owncloud.android.utils.MimeTypeUtil;
 import com.owncloud.android.utils.ThemeUtils;
 
 import java.text.SimpleDateFormat;
-import java.util.ArrayList;
+import java.util.List;
 import java.util.Date;
 
 /**
@@ -109,7 +109,7 @@ public class ShareFileFragment extends Fragment implements ShareUserListAdapter.
     /**
      * List of private shares bound to the file.
      */
-    private ArrayList<OCShare> mPrivateShares;
+    private List<OCShare> mPrivateShares;
 
     /**
      * Capabilities of the server.
@@ -129,22 +129,22 @@ public class ShareFileFragment extends Fragment implements ShareUserListAdapter.
     /**
      * Listener for user actions to set, update or clear password on public link.
      */
-    private OnPasswordInteractionListener mOnPasswordInteractionListener = null;
+    private OnPasswordInteractionListener mOnPasswordInteractionListener;
 
     /**
      * Listener for user actions to set, update or clear expiration date on public link.
      */
-    private OnExpirationDateInteractionListener mOnExpirationDateInteractionListener = null;
+    private OnExpirationDateInteractionListener mOnExpirationDateInteractionListener;
 
     /**
      * Listener for user actions to set or unset edit permission on public link.
      */
-    private OnEditPermissionInteractionListener mOnEditPermissionInteractionListener = null;
+    private OnEditPermissionInteractionListener mOnEditPermissionInteractionListener;
 
     /**
      * Listener for user actions to set or unset hide file listing permission on public link.
      */
-    private OnHideFileListingPermissionInteractionListener mOnHideFileListingPermissionInteractionListener = null;
+    private OnHideFileListingPermissionInteractionListener mOnHideFileListingPermissionInteractionListener;
 
     /**
      * Public factory method to create new ShareFileFragment instances.

src/main/java/com/owncloud/android/ui/fragment/contactsbackup/ContactListFragment.java

@@ -139,7 +139,7 @@ public class ContactListFragment extends FileFragment {
 
     private ContactListAdapter contactListAdapter;
     private Account account;
-    private ArrayList<VCard> vCards = new ArrayList<>();
+    private List<VCard> vCards = new ArrayList<>();
     private OCFile ocFile;
 
     public static ContactListFragment newInstance(OCFile file, Account account) {

src/main/java/com/owncloud/android/ui/fragment/contactsbackup/ContactsBackupFragment.java

@@ -89,7 +89,7 @@ public class ContactsBackupFragment extends FileFragment implements DatePickerDi
     @BindView(R.id.contacts_backup_now)
     public AppCompatButton backupNow;
 
-    private Date selectedDate = null;
+    private Date selectedDate;
     private boolean calendarPickerOpen;
 
     private DatePickerDialog datePickerDialog;

src/main/java/com/owncloud/android/ui/helpers/SparseBooleanArrayParcelable.java

@@ -41,12 +41,8 @@ public class SparseBooleanArrayParcelable implements Parcelable {
 
             // then pairs of (key, value)s, in the object to wrap
             SparseBooleanArray sba = new SparseBooleanArray();
-            int key;
-            boolean value;
             for (int i = 0; i < size; i++) {
-                key = source.readInt();
-                value = (source.readInt() != 0);
-                sba.put(key, value);
+                sba.put(source.readInt(), source.readInt() != 0);
             }
 
             // wrap SparseBooleanArray

src/main/java/com/owncloud/android/ui/helpers/UriUploader.java

@@ -52,7 +52,7 @@ public class UriUploader {
     private final String TAG = UriUploader.class.getSimpleName();
 
     private FileActivity mActivity;
-    private ArrayList<Parcelable> mUrisToUpload;
+    private List<Parcelable> mUrisToUpload;
     private CopyAndUploadContentUrisTask.OnCopyTmpFilesTaskListener mCopyTmpTaskListener;
 
     private int mBehaviour;
@@ -72,7 +72,7 @@ public class UriUploader {
 
     public UriUploader(
             FileActivity activity,
-            ArrayList<Parcelable> uris,
+            List<Parcelable> uris,
             String uploadPath,
             Account account,
             int behaviour,

src/main/java/com/owncloud/android/ui/preview/PreviewImageActivity.java

@@ -75,13 +75,10 @@ public class PreviewImageActivity extends FileActivity implements
 
     private ViewPager mViewPager;
     private PreviewImagePagerAdapter mPreviewImagePagerAdapter;
-    private int mSavedPosition = 0;
-    private boolean mHasSavedPosition = false;
-    
+    private int mSavedPosition;
+    private boolean mHasSavedPosition;
     private boolean mRequestWaitingForBinder;
-    
     private DownloadFinishReceiver mDownloadFinishReceiver;
-    
     private View mFullScreenAnchorView;
 
     @Override

src/main/java/com/owncloud/android/ui/preview/PreviewImageFragment.java

@@ -105,9 +105,9 @@ public class PreviewImageFragment extends FileFragment {
     private ImageView mMultiListIcon;
     private ProgressBar mMultiListProgress;
 
-    private Boolean mShowResizedImage = false;
+    private Boolean mShowResizedImage;
 
-    private Bitmap mBitmap = null;
+    private Bitmap mBitmap;
 
     private static final String TAG = PreviewImageFragment.class.getSimpleName();
 

src/main/java/com/owncloud/android/ui/preview/PreviewMediaFragment.java

@@ -110,11 +110,11 @@ public class PreviewMediaFragment extends FileFragment implements
     protected ImageView mMultiListIcon;
     protected ProgressBar mMultiListProgress;
 
-    private MediaServiceBinder mMediaServiceBinder = null;
-    private MediaControlView mMediaController = null;
-    private MediaServiceConnection mMediaServiceConnection = null;
+    private MediaServiceBinder mMediaServiceBinder;
+    private MediaControlView mMediaController;
+    private MediaServiceConnection mMediaServiceConnection;
     private boolean mAutoplay;
-    private static boolean mOnResume = false;
+    private static boolean mOnResume;
     public boolean mPrepared;
 
     private Uri mVideoUri;
@@ -128,7 +128,7 @@ public class PreviewMediaFragment extends FileFragment implements
 
     /**
      * Creates a fragment to preview a file.
-     * <p/>
+     *
      * When 'fileToDetail' or 'ocAccount' are null
      *
      * @param fileToDetail An {@link OCFile} to preview in the fragment