What I understand from your post is that you have the data in a String literal, and wish to create an instance of Workbook from it. If my understanding is correct, you can achieve the goal as demonstrated below.
Java
String input = “1, 2, 3, 4\n” + “5, 6, 7, 8”; //Assumes that you want an InputStream that is a stream of bytes that represent your original string encoded as UTF-8 InputStream stream = new ByteArrayInputStream(input.getBytes(StandardCharsets.UTF_8)); Workbook book = new Workbook(stream, new TxtLoadOptions()); book.save(dir + “output.xlsx”);