Simple Java Chess Library

Chesslib is a simple java chess library for doing things like generating legal chess moves given a chessboard position, parse a chess game stored in PGN or FEN format and many other things.

Building/Installing

mvn clean compile package install

Usage

Create a chessboard and make a move

    // Creates a new chessboard in the standard initial position
    Board board = new Board();

    //Make a move from E2 to E4 squares
    board.doMove(new Move(Square.E2, Square.E4));

    //print the chessboard in a human-readable form
    System.out.println(board.toString());

Result:

rnbqkbnr
pppppppp


    P

PPPP PPP
RNBQKBNR
Side: BLACK

Undo a move

    // Undo a move from the stack and return it
    Move move = board.undoMove();

Load a chessboard position from FEN notation

    // Load a FEN position into the chessboard
    String fen = "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1";
    Board board = new Board();
    board.loadFromFEN(fen);

    //Find the square locations of black bishops
    List<Square> blackBishopSquares = board.getPieceLocation(Piece.BLACK_BISHOP);

    //Get the piece at A1 square...
    Piece piece = board.getPiece(Square.A1);

Generate all chess legal-moves for the current position

    // Generate legal chess moves for the current position
    Board board = new Board();
    MoveList moves = MoveGenerator.getInstance().generateLegalMoves(board);
    System.out.println("Legal moves: " + moves);

Result:

  a2a3 a2a4 b2b3 b2b4 c2c3 c2c4 d2d3 d2d4 e2e3 e2e4 f2f3 f2f4 g2g3 g2g4 h2h3 h2h4 b1a3 b1c3 g1f3 g1h3

Checking for position situations

The current chessboard state can be checked using methods like board.isDraw(), board.isInsufficientMaterial(), board.isStaleMate(), board.isKingAttacked(), board.isMated(), board.getSideToMove(), etc.

Load a chess game collection from a PGN file

    PgnHolder pgn = new PgnHolder("/opt/games/linares_2002.pgn");
    pgn.loadPgn();
    for (Game game: pgn.getGame()) {
        game.loadMoveText();
        MoveList moves = game.getHalfMoves();
        Board board = new Board();
        //Replay all the moves from the game and print the final position in FEN format
        for (Move move: moves) {
            board.doMove(move);
        }
        System.out.println("FEN: " + board.getFEN());
    }

You could have done the same by only:

    ...
    board.loadFromFEN(moves.getFEN());

Advanced usage

[TODO]

somegituser123 / chesslib