code: private void loadRootFolder() {
          new Thread() {
              @Override
              public void run() {
                  try {
                      //Api to fetch root folder
                      final BoxIteratorItems folderItems = mFolderApi.getItemsRequest(BoxConstants.ROOT_FOLDER_ID).send();
                      runOnUiThread(new Runnable() {
                          @Override
                          public void run() {
                              mAdapter.clear();
                              for (BoxItem boxItem: folderItems) {
                                  mAdapter.add(boxItem);
                              }
                          }
                      });
                  } catch (BoxException e) {
                      e.printStackTrace();
                  }
  
              }
          }.start();
      }
docs: Method to demonstrate fetching folder items from the root folder