Use try-with-resources to autoclose closable resources

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

@@ -26,7 +26,6 @@ import android.net.Uri;
 
 import com.owncloud.android.db.ProviderMeta;
 import com.owncloud.android.lib.common.utils.Log_OC;
-import com.owncloud.android.utils.IOHelper;
 
 import java.io.BufferedInputStream;
 import java.io.FileInputStream;
@@ -214,9 +213,7 @@ public class FilesystemDataProvider {
 
     private long getFileChecksum(String filepath) {
 
-        InputStream inputStream = null;
-        try {
-            inputStream = new BufferedInputStream(new FileInputStream(filepath));
+        try (InputStream inputStream = new BufferedInputStream(new FileInputStream(filepath))){
             CRC32 crc = new CRC32();
             int cnt;
             while ((cnt = inputStream.read()) != -1) {
@@ -229,8 +226,6 @@ public class FilesystemDataProvider {
             return -1;
         } catch (IOException e) {
             return -1;
-        } finally {
-            IOHelper.close(inputStream);
         }
     }
 }

src/main/java/com/owncloud/android/jobs/ContactsImportJob.java

@@ -30,7 +30,6 @@ import com.evernote.android.job.Job;
 import com.evernote.android.job.util.support.PersistableBundleCompat;
 import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.ui.fragment.contactsbackup.ContactListFragment;
-import com.owncloud.android.utils.IOHelper;
 
 import java.io.File;
 import java.io.IOException;
@@ -116,9 +115,7 @@ public class ContactsImportJob extends Job {
         String lookupKey = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY));
         Uri uri = Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_VCARD_URI, lookupKey);
         VCard vCard = null;
-        InputStream inputStream = null;
-        try {
-            inputStream = getContext().getContentResolver().openInputStream(uri);
+        try (InputStream inputStream = getContext().getContentResolver().openInputStream(uri)){
             ArrayList<VCard> vCardList = new ArrayList<>();
             vCardList.addAll(Ezvcard.parse(inputStream).all());
             if (vCardList.size() > 0) {
@@ -127,8 +124,6 @@ public class ContactsImportJob extends Job {
 
         } catch (IOException e) {
             Log_OC.d(TAG, e.getMessage());
-        } finally {
-            IOHelper.close(inputStream);
         }
         return vCard;
     }

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

@@ -37,7 +37,6 @@ import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.lib.resources.files.DownloadRemoteFileOperation;
 import com.owncloud.android.utils.EncryptionUtils;
 import com.owncloud.android.utils.FileStorageUtils;
-import com.owncloud.android.utils.IOHelper;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -202,16 +201,12 @@ public class DownloadFileOperation extends RemoteOperation {
                 byte[] authenticationTag = EncryptionUtils.decodeStringToBase64Bytes(metadata.getFiles()
                         .get(mFile.getEncryptedFileName()).getAuthenticationTag());
 
-                FileOutputStream fileOutputStream = null;
-                try {
+                try (FileOutputStream fileOutputStream = new FileOutputStream(tmpFile)){
                     byte[] decryptedBytes = EncryptionUtils.decryptFile(tmpFile, key, iv, authenticationTag);
 
-                    fileOutputStream = new FileOutputStream(tmpFile);
                     fileOutputStream.write(decryptedBytes);
                 } catch (Exception e) {
                     return new RemoteOperationResult(e);
-                } finally {
-                    IOHelper.close(fileOutputStream);
                 }
             }
             moved = tmpFile.renameTo(newFile);

src/main/java/com/owncloud/android/utils/IOHelper.java

@@ -1,24 +0,0 @@
-package com.owncloud.android.utils;
-
-import com.owncloud.android.lib.common.utils.Log_OC;
-
-import java.io.Closeable;
-import java.io.IOException;
-
-/**
- * Static system IO helper methods
- */
-
-public class IOHelper {
-    private static final String TAG = IOHelper.class.getSimpleName();
-
-    public static void close(Closeable c) {
-        if (c == null) return;
-        try {
-            c.close();
-        } catch (IOException e) {
-            Log_OC.e(TAG, "Error closing stream", e);
-        }
-    }
-
-}

src/test/java/com/owncloud/android/utils/IOHelperTest.java

@@ -1,46 +0,0 @@
-package com.owncloud.android.utils;
-
-import junit.framework.Assert;
-
-import org.junit.Test;
-
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Paths;
-
-import static junit.framework.Assert.assertEquals;
-
-/**
- * Unit tests for the ({@link IOHelper}) class.
- */
-
-public class IOHelperTest {
-
-    private final static String outputFileName = "output.txt";
-
-    @Test
-    public void testInputStreamIsClosed() throws Exception {
-        // Define FileOutputStream for testing.
-        FileOutputStream mOutputStream = null;
-        try {
-            // init object
-            mOutputStream = new FileOutputStream(outputFileName);
-
-        } catch (Exception ex) {
-            ex.printStackTrace();
-        } finally {
-            // Close output stream.
-            IOHelper.close(mOutputStream);
-        }
-        // try to write to stream. This should fail since we have now closed the output stream.
-        try {
-            mOutputStream.write("Hello World".getBytes());
-            Assert.fail("No exception was thrown");
-        } catch (IOException e) {
-            assertEquals(e.getMessage(), "Stream Closed");
-        }
-
-        Files.deleteIfExists(Paths.get(outputFileName));
-    }
-}