* APPLY GRAVITY METHOD *

 private boolean applyGravity(int exceptRow, int exceptCol) {
        boolean fellOnPlayer = false;
        for (int r = rows - 2; r > -1; r--) { //a massive object can thus not be moved off the board!
            for (int c = 0; c < cols; c++) {
                if (world[r][c].hasMass()) {

                    if ((world[r + 1][c].isVulnerable()) && !(r + 1 == exceptRow) && !(c == exceptCol)) {

                        if (world[r + 1][c] instanceof Alien) {
                             alienDead = true;
                            System.out.println("Alien is dead!");
                    } else if (world[r+1][c].isPlayer()) {
                        fellOnPlayer = true;
                        System.out.println("Player is dead!");
                    }
                    else {
                        WorldObject falling = world[r][c];
                        world[r+1][c] = world[r][c];
                        world[r-1][c] = new Space();

                        }
                    }
                }

            }
        }
        return fellOnPlayer;
    }


* MAIN METHOD *

class Main
{
    /**
     * Main entry point.
     */
    public static void main(final String[] args) throws BadFileFormatException
    {
        Tests.testLoadFile("example.txt");
        Tests.testLoadFile("example2.txt");
        Tests.testLoadFile("example3.txt");
        final World world = new World(10, 10, 7);

        // Play the game
        int outcome = 0;
        while (outcome == 0)
        {
            System.out.println(world);
            final char ch = world.getMove();
            if (!world.validMove(ch))
                System.out.println("Error. Please enter u,d,l,r.");
            else
                outcome = world.applyMove(ch);
        }

        // Show the result
        System.out.println(world + "\n");
        if (outcome == 1)
            System.out.println("Yay! You won!");
        else
            System.out.println("Whoops, you lost........ :-/");
    }
}


* OUTPUT *

Emeralds remaining: 16
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 Error : invalid character . The error is at row  11 and at col 8
Emeralds remaining: 20
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 Error : remaining emeralds cannot be more than total worth of emeralds . The error is at row  2 and at col 0
Emeralds remaining: 25
###.p#e###
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Emeralds remaining: 16
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Where to? d
Emeralds remaining: 16
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Where to? d
Emeralds remaining: 16
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Where to? d
Emeralds remaining: 16
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Where to? d
Emeralds remaining: 16
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Where to? d
Emeralds remaining: 16
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Where to? l
Emeralds remaining: 16
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Where to? l
Emeralds remaining: 16
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Where to? l
Emeralds remaining: 16
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Where to? l
Emeralds remaining: 16
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