public class Tile 
{
    private String name;
 
    public Tile(String name)
    {
         this.name = name;
    }
    public String toString()
    {
        return name;
    }
}

import java.util.ArrayList;
import java.util.Random;
public class FooList 
{
    private final int fooLength;
    private ArrayList<String> availableFoos;
 
    public FooList(int len)
    {
       fooLength = len;
       availableFoos = new ArrayList<String>();
    }
    public String getFoo(int x)
    {
        return availableFoos.get(x);
    }
    public boolean found(String key)
    {
       for(int x = 0; x < availableFoos.size(); x++)
       {
           if(key.equals(availableFoos.get(x)))
               return true;
       }
       return false;
    }
    public void addFoo(String foo)
    {
        if(found(foo) || foo.length() != fooLength)
           return;
        availableFoos.add(foo);
    }
   public String removeRandomFoo()
   {
     Random random = new Random();
     int max = availableFoos.size() - 1;
     int rnd = (random.nextInt() * max);
     String foo = availableFoos.get(rnd);
     availableFoos.remove(rnd);
     return foo;
   }
}

import java.util.ArrayList;
 
public class Board 
{
   private Tile[] gameboard;
   private int size;
   private int rowlength;
   int numberOfTilesFaceUp;
   private FooList possibleTileValues;
 
   public Board(int n, FooList list)
   {
      gameboard = new Tile[n * n];
      size = gameboard.length;
      numberOfTilesFaceUp = 0;
      rowlength = 0;
      possibleTileValues = list;
      fillBoard();
   }
   private void fillBoard()
   {
       //so confused
   }
   public static void main(String args[])
   {  //for debugging purposes
       FooList list = new FooList(4);
       list.addFoo("cats");
       list.addFoo("dogs");
       list.addFoo("bird");
       list.addFoo("mice");
       list.addFoo("fish");
       Board board = new Board(4, list);
   } 
}