Get the formatted text of a file size

getFileSizeFormatedTxt.java

// What you input: file size (long or its sub type)
// What you get: formatted text of a file size.
//               ex) 23.44 MBytes, 15.20 TBytes, 1,015 Bytes, ...
public static String getFileSizeFormatedTxt(long fileSize) {
  
  // Unit size infoes
  Object[][] bytes = {
    {1099511627776L, "T"},
    {1073741824L   , "G"},
    {1048576L      , "M"},
    {1024L         , "k"}
  };
  
  // Make the string. "XX.XX G", "XX.XX M", ...
  String s = "";
  for(Object[] o: bytes)
    if(fileSize >= (long)o[0]) {
      s = String.format(
        "%,.2f %s",
        (float)fileSize / (long)o[0],
        o[1]
      );
      break;
  }
  if(s == "") s = String.format("%,d ", fileSize);
  
  // Retrun the result
  return s + "Bytes";
  
}

getFileSizeFormatedTxt_SHORTER.java

// Returns the size string using kB, MB, Gb, ... format
private static String getFileSizeFormatedTxt(long fileSize) {
  Object[][] sizeInfoes = { {1099511627776L, "T"}, {1073741824L, "G"}, {1048576L, "M"}, {1024L, "k"} };
  String s = "";
  for(Object[] o: sizeInfoes) if(fileSize >= (long)o[0]) {
      s = String.format("%,.2f %s", (float)fileSize / (long)o[0], o[1] );
      break;
  }
  if(s == "") s = String.format("%,d ", fileSize);
  return s + "Bytes";
}