DigitAL

Demostration of Fluent interfaces / TDD / Functional idioms applied with OOPS

A simple application to parse digits (from Pipes and underscores) and display the digit/number formed by the digit.

The application will take a input stream (can be a file) having Raw Account Numbers (probably read from a digital machine) formed by pipes and underscores, with one account number on each line.

Each entry in the file is 4 lines long, and each line has 27 characters. The first 3 lines of each entry contain an account number written using pipes and underscores, and the fourth line is blank. Each account number should have 9 digits, all of which should be in the range 0-9. A normal file contains around 500 entries.

VALID / INVALID:

Any digit which can't be interpreted will be replaced by a question mark '?' and will become invalid
Checksum of each account number should be divisible by 11 (account is valid if checksum % 11 == 0)

      account number:  3  4  5  8  8  2  8  6  5
      position names:  d9 d8 d7 d6 d5 d4 d3 d2 d1

      checksum calculation: (d1+2*d2+3*d3 +..+9*d9)

USAGE:

    final String FILE_NAME = "data.txt";
    try (FileInputStream dataFile = new FileInputStream(FILE_NAME)) {
        Accounts
                .from(dataFile)
                .forEach(System.out::println);
    }

TEST:

    String rawAccountNumbers =
                  "    _  _     _  _  _  _  _ \n" +
                  "  | _| _||_||_ |_   ||_||_|\n\r" +
                  "  ||_  _|  | _||_|  ||_| _|\n\r" +
                  "                           \n" +
                  "    _  _  _  _  _  _  _  _ \n" +
                  "  | _| _||_ |_ |_   ||_|| |\n\r" +
                  "  | _| _| _||_||_|  ||_||_|\n\r" +
                  "                           ";
    
    Collection accounts = Accounts.from(new ByteArrayInputStream(rawAccountNumbers.getBytes()));
    
    assertThat(accounts, hasAccountsInOrder("123456789", "133566780"));

MORE DETAILS:

This is a implementation of first three stories of the code kata hosted at http://codingdojo.org/cgi-bin/index.pl?KataBankOCR
Please visit the link for more details