Question

The application need write file’s last modification date.

 void Dater(String DateFile) {
          File file = new File(DateFile);
          if(file.exists()){
              Long lastModified = file.lastModified();
              Date date = new Date(lastModified);
              textView2.setText(String.valueOf(date));
          }
      }

But textView2 is empty.
The file is ok (I open it).

Dater("n" + String.valueOf(itemname)+".txt");

Answer 1

I think your file.exists() fails. Give the absolute path of the file

If internal file then

Dater(activity.getFilesDir().getAbsolutePath() + "/n" + String.valueOf(itemname)+".txt");

If on the sdcard then

Dater(Environment.getExternalStorageDirectory() + "/n" + String.valueOf(itemname)+".txt");