Nitin Lama
--- a/src/Form/FileAddArchiveForm.php
+++ b/src/Form/FileAddArchiveForm.php
        $extract_dir = $this->config('system.file')->get('default_scheme') . '://' . pathinfo($archive->getFilename(), PATHINFO_FILENAME);
        $extract_dir = $this->fileSystem->getDestinationFilename($extract_dir, FileSystemInterface::EXISTS_RENAME);
        if (!$this->fileSystem->prepareDirectory($extract_dir, FileSystemInterface::MODIFY_PERMISSIONS | FileSystemInterface::CREATE_DIRECTORY)) {
-          throw new \Exception(t('Unable to prepare, the directory %dir for extraction.', array('%dir' => $extract_dir)));
+          throw new \Exception($this->t('Unable to prepare, the directory %dir for extraction.', array('%dir' => $extract_dir)));
--- a/tests/src/Functional/FileEntityAdminTest.php
+++ b/tests/src/Functional/FileEntityAdminTest.php
    $this->assertSession()->linkByHrefExists('file/1/delete');
    $this->assertSession()->linkByHrefExists('file/2/delete');
    $this->drupalGet('file/1/delete');
-    $this->assertSession()->titleEquals((string) t('Are you sure you want to delete the file @filename? | Drupal', array('@filename' => FileEntity::load(1)->label())));
+    $this->assertSession()->titleEquals((string) $this->t('Are you sure you want to delete the file @filename? | Drupal', array('@filename' => FileEntity::load(1)->label())));
--- a/src/Controller/FileController.php
+++ b/src/Controller/FileController.php
 */
 class FileController extends ControllerBase {

+  use StringTranslationTrait;
+
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
--- a/src/Controller/FileController.php
+++ b/src/Controller/FileController.php
    // Ensure there is a valid token to download this file.
    if (!$this->config('file_entity.settings')->get('allow_insecure_download')) {
      if (!isset($_GET['token']) || $_GET['token'] !== $file->getDownloadToken()) {
-        return new Response(t('Access to file @url denied', array('@url' => $file->getFileUri())), 403);
+        return new Response($this->getStringTranslation()->translate('Access to file @url denied', array('@url' => $file->getFileUri())), 403);
--- a/src/Controller/FileController.php
+++ b/src/Controller/FileController.php
      return new BinaryFileResponse($file->getFileUri(), 200, $headers, FALSE, 'attachment');
    }
    catch (FileNotFoundException $e) {
-      return new Response(t('File @uri not found', array('@uri' =>$file->getFileUri())), 404);
+      return new Response($this->getStringTranslation()->translate('File @uri not found', array('@uri' =>$file->getFileUri())), 404);
--- a/src/Controller/FileController.php
+++ b/src/Controller/FileController.php
    if (!$form_state->isExecuted()) {
      // Return the form as a modal dialog.
      $form['#attached']['library'][] = 'core/drupal.dialog.ajax';
-      $title = $this->t('Edit file @file', ['@file' => $file->label()]);
+      $title = $this->getStringTranslation()->translate('Edit file @file', ['@file' => $file->label()]);
--- a/src/Form/FileAddArchiveForm.php
+++ b/src/Form/FileAddArchiveForm.php
 class FileAddArchiveForm extends FormBase {

  use UploadValidatorsTrait;
-
+  use StringTranslationTrait;
+  
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
--- a/src/Form/FileAddArchiveForm.php
+++ b/src/Form/FileAddArchiveForm.php

    $form['upload'] = array(
      '#type' => 'managed_file',
-      '#title' => $this->t('Upload an archive file'),
+      '#title' => $this->getStringTranslation()->translate('Upload an archive file'),
--- a/src/Form/FileAddArchiveForm.php
+++ b/src/Form/FileAddArchiveForm.php

    $form['upload'] = array(
      '#type' => 'managed_file',
-      '#title' => $this->t('Upload an archive file'),
+      '#title' => $this->getStringTranslation()->translate('Upload an archive file'),
      '#upload_location' => 'public://',
      '#progress_indicator' => 'bar',
      '#default_value' => $form_state->has('file') ? array($form_state->get('file')->id()) : NULL,
      '#required' => TRUE,
-      '#description' => $this->t('Files must be less than <strong>%valid_size</strong><br> Allowed file types: <strong>%valid_extension</strong>', array('%valid_size' => format_size($validators['file_validate_size'][0]), '%valid_extension' => $validators['file_validate_extensions'][0])),
+      '#description' => $this->getStringTranslation()->translate('Files must be less than <strong>%valid_size</strong><br> Allowed file types: <strong>%valid_extension</strong>', array('%valid_size' => format_size($validators['file_validate_size'][0]), '%valid_extension' => $validators['file_validate_extensions'][0])),
--- a/src/Form/FileAddArchiveForm.php
+++ b/src/Form/FileAddArchiveForm.php
+      '#title' => $this->getStringTranslation()->translate('Upload an archive file'),
      '#upload_location' => 'public://',
      '#progress_indicator' => 'bar',
      '#default_value' => $form_state->has('file') ? array($form_state->get('file')->id()) : NULL,
      '#required' => TRUE,
-      '#description' => $this->t('Files must be less than <strong>%valid_size</strong><br> Allowed file types: <strong>%valid_extension</strong>', array('%valid_size' => format_size($validators['file_validate_size'][0]), '%valid_extension' => $validators['file_validate_extensions'][0])),
+      '#description' => $this->getStringTranslation()->translate('Files must be less than <strong>%valid_size</strong><br> Allowed file types: <strong>%valid_extension</strong>', array('%valid_size' => format_size($validators['file_validate_size'][0]), '%valid_extension' => $validators['file_validate_extensions'][0])),
      '#upload_validators' => $validators,
    );

    $form['pattern'] = array(
      '#type' => 'textfield',
-      '#title' => $this->t('Pattern'),
-      '#description' => $this->t('Only files matching this pattern will be imported. For example, to import all jpg and gif files, the pattern would be <strong>.*jpg|.*gif</strong>. Use <strong>.*</strong> to extract all files in the archive.'),
+      '#title' => $this->getStringTranslation()->translate('Pattern'),
+      '#description' => $this->getStringTranslation()->translate('Only files matching this pattern will be imported. For example, to import all jpg and gif files, the pattern would be <strong>.*jpg|.*gif</strong>. Use <strong>.*</strong> to extract all files in the archive.'),
--- a/src/Form/FileAddArchiveForm.php
+++ b/src/Form/FileAddArchiveForm.php

    $form['pattern'] = array(
      '#type' => 'textfield',
-      '#title' => $this->t('Pattern'),
-      '#description' => $this->t('Only files matching this pattern will be imported. For example, to import all jpg and gif files, the pattern would be <strong>.*jpg|.*gif</strong>. Use <strong>.*</strong> to extract all files in the archive.'),
+      '#title' => $this->getStringTranslation()->translate('Pattern'),
+      '#description' => $this->getStringTranslation()->translate('Only files matching this pattern will be imported. For example, to import all jpg and gif files, the pattern would be <strong>.*jpg|.*gif</strong>. Use <strong>.*</strong> to extract all files in the archive.'),
      '#default_value' => '.*',
      '#required' => TRUE,
    );

    $form['remove_archive'] = array(
      '#type' => 'checkbox',
-      '#title' => $this->t('Remove archive'),
-      '#description' => $this->t('Removes archive after extraction.'),
+      '#title' => $this->getStringTranslation()->translate('Remove archive'),
--- a/src/Form/FileAddArchiveForm.php
+++ b/src/Form/FileAddArchiveForm.php
    $form['pattern'] = array(
      '#type' => 'textfield',
-      '#title' => $this->t('Pattern'),
-      '#description' => $this->t('Only files matching this pattern will be imported. For example, to import all jpg and gif files, the pattern would be <strong>.*jpg|.*gif</strong>. Use <strong>.*</strong> to extract all files in the archive.'),
+      '#title' => $this->getStringTranslation()->translate('Pattern'),
+      '#description' => $this->getStringTranslation()->translate('Only files matching this pattern will be imported. For example, to import all jpg and gif files, the pattern would be <strong>.*jpg|.*gif</strong>. Use <strong>.*</strong> to extract all files in the archive.'),
      '#default_value' => '.*',
      '#required' => TRUE,
    );

    $form['remove_archive'] = array(
      '#type' => 'checkbox',
-      '#title' => $this->t('Remove archive'),
-      '#description' => $this->t('Removes archive after extraction.'),
+      '#title' => $this->getStringTranslation()->translate('Remove archive'),
+      '#description' => $this->getStringTranslation()->translate('Removes archive after extraction.'),
--- a/src/Form/FileEditForm.php
+++ b/src/Form/FileEditForm.php
 class FileEditForm extends ContentEntityForm {

  use UploadValidatorsTrait;
+  use StringTranslationTrait;

+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
--- a/src/Plugin/Field/FieldFormatter/FileImageFormatter.php
+++ b/src/Plugin/Field/FieldFormatter/FileImageFormatter.php
 */
 class FileImageFormatter extends ImageFormatter {

+  use StringTranslationTrait;
+
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
+  public function __construct(TranslationInterface $translation) {
+    $this->setStringTranslation($translation);
--- a/src/Plugin/Field/FieldFormatter/FileDownloadLinkFormatter.php
+++ b/src/Plugin/Field/FieldFormatter/FileDownloadLinkFormatter.php
 */
 class FileDownloadLinkFormatter extends FileFormatterBase implements ContainerFactoryPluginInterface {

+  use StringTranslationTrait;
+
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
+  public function __construct(TranslationInterface $translation) {
+    $this->setStringTranslation($translation);
+  }
--- a/src/Form/FileTypeForm.php
+++ b/src/Form/FileTypeForm.php
 */
 class FileTypeForm extends EntityForm {

+  use StringTranslationTrait;
+
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
+  public function __construct(TranslationInterface $translation) {
+    $this->setStringTranslation($translation);
+  }
--- a/src/Plugin/Field/FieldWidget/FileEditableWidget.php
+++ b/src/Plugin/Field/FieldWidget/FileEditableWidget.php
 */
 class FileEditableWidget extends FileWidget {

+  use StringTranslationTrait;
+
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
+  public function __construct(TranslationInterface $translation) {
+    $this->setStringTranslation($translation);
+  }
--- a/tests/src/Functional/FileEntityAdminTest.php
+++ b/tests/src/Functional/FileEntityAdminTest.php
 */
 class FileEntityAdminTest extends FileEntityTestBase {

+  use StringTranslationTrait;
+
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
+  public function __construct(TranslationInterface $translation) {
+    $this->setStringTranslation($translation);
+  }
--- a/tests/src/Functional/FileEntityCreationTest.php
+++ b/tests/src/Functional/FileEntityCreationTest.php
 */
 class FileEntityCreationTest extends FileEntityTestBase {

+  use StringTranslationTrait;
+
+  /**
+   * Class constructor.
+   *
+   * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
+   *   The translation service.
+   */
+  public function __construct(TranslationInterface $translation) {
+    $this->setStringTranslation($translation);
+  }