FEN is a notation used to describe a chess position. You can read about it on wikipedia: https://en.wikipedia.org/wiki/ForsythEdwards_Notation and another quick intro here: http://www.chessgames.com/fenhelp.html

We want to design a class to encapsulate a FEN chess position and print out some information. We also want to make sure the FEN is correct.

Create an InvalidFenException class, similar to the example from class.

Copy and paste the ChessGameClient.

Create a ChessGame class using the instructions below.

Have fun!

ChessGameFields

String pieces

Character activeColor

String castlingOptions

String enPassant

MethodsConstructor

ChessGame

Takes in a single argument, a String containing the entire FEN.

This constructor may throw an InvalidFenException.

Use the Scanner class to parse the FEN by spaces.

Throw an InvalidFenException for missing data.

If the activeColor is not a b or w, throw an InvalidFenException.

Using a regular expression to check if the castling options are valid, if not, throw an InvalidFenException.

Use a regular expression to check if the en passant is valid, if not, throw an InvalidFenException.

PrintBoard

Void method that prints out some information.

Use the Scanner class to parse the pieces by slashes.

Use the algorithm below.

Print if it is white's move or black's move.

Print the castling options, or not available if there are none.

Print if en passant is available or not.

Parse the pieces by slashes. while there is a next field for i = 0; i < length; i++ get the character in the field at index i if that character is a digit convert it to an int Use a for loop to print that many .'s otherwise print the character and a space 

public class ChessGameClient { public static void main(String[] args) { String[] boards = { "2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w -", "2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w", "2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 k - -", "2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w KQk- -", "2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w - k3", "2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w - a9", "2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w - -", "r2q1rk1/5pbp/2n1p1p1/p7/Pp1PpB2/1NP4P/1P3PP1/R2Q1RK1 b - -", "rnbqkbnr/pppppppp/8/8/3P4/8/PPP1PPPP/RNBQKBNR b KQkq d3"}; System.out.println("-----------------------------"); for (String b : boards) { System.out.println(b); try { ChessGame cg = new ChessGame(b); cg.printBoard(); } catch (InvalidFenException ife) { System.err.println(ife.getMessage()); } System.out.println("-----------------------------"); } } } 

Desired output:

----------------------------- 2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w - Error, missing fields. ----------------------------- 2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w Error, missing fields. ----------------------------- 2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 k - - Error, active color is invalid. ----------------------------- 2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w KQk- - Error, castling is invalid. ----------------------------- 2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w - k3 Error, en passant is invalid. ----------------------------- 2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w - a9 Error, en passant is invalid. ----------------------------- 2r1brk1/1p5p/p1nQ3P/2N2pq1/3P4/2P2p2/P4PP1/2R1R1K1 w - - . . r . b r k . . p . . . . . p p . n Q . . . P . . N . . p q . . . . P . . . . . . P . . p . . P . . . . P P . . . R . R . K . It is white's move. It is not possible to castle. En passant is not available. ----------------------------- r2q1rk1/5pbp/2n1p1p1/p7/Pp1PpB2/1NP4P/1P3PP1/R2Q1RK1 b - - r . . q . r k . . . . . . p b p . . n . p . p . p . . . . . . . P p . P p B . . . N P . . . . P . P . . . P P . R . . Q . R K . It is black's move. It is not possible to castle. En passant is not available. ----------------------------- rnbqkbnr/pppppppp/8/8/3P4/8/PPP1PPPP/RNBQKBNR b KQkq d3 r n b q k b n r p p p p p p p p . . . . . . . . . . . . . . . . . . . P . . . . . . . . . . . . P P P . P P P P R N B Q K B N R It is black's move. The castling options are: KQkq En passant is available. -----------------------------