I think I did fairly well

src/Card.java

@@ -1,7 +1,66 @@
 public class Card {
   // Create the rest of this class yourself
 
-  public boolean equals(Object obj) {
+  private int quantity;
+  private int color;
+  private int shading;
+  private int shape;
+
+  public Card(int cardQuantity, int cardColor, int cardShading, int cardShape)
+  {
+    quantity = (cardQuantity % 3 + 3) % 3;
+    if (quantity == 0)
+      quantity += 3;
+
+    color = (cardColor % 3 + 3) % 3;
+    if (color == 0)
+      color += 3;
+
+    shading = (cardShading % 3 + 3) % 3;
+    if (shading == 0)
+      shading += 3;
+
+    shape = (cardShape % 3 + 3) % 3;
+    if (shape == 0)
+      shape += 3;
+  }
+
+  public int getQuantity()
+  {
+    return quantity;
+  }
+
+  public int getColor()
+  {
+    return color;
+  }
+
+  public int getShading()
+  {
+    return shading;
+  }
+
+  public int getShape()
+  {
+    return shape;
+  }
+
+  public String toString()
+  {
+    char[] letters = new char[] {'R', 'G', 'P', 'O', 'T', 'S', 'O', 'D', 'S'};
+    return String.valueOf(quantity) + letters[color - 1] + letters[shading + 2] + letters[shape + 5];
+  }
+
+  public boolean isSet(Card card2, Card card3)
+  {
+    return (quantity + card2.getQuantity() + card3.getQuantity()) % 3 == 0 &&
+      (color + card2.getColor() + card3.getColor()) % 3 == 0 &&
+      (shading + card2.getShading() + card3.getShading()) % 3 == 0 &&
+      (shape + card2.getShape() + card3.getShape()) % 3 == 0;
+  }
+
+  public boolean equals(Object obj) 
+  {
     Card that = (Card)obj;
 
     return quantity == that.getQuantity() &&

src/CardTest.java

@@ -0,0 +1,93 @@
+import junit.framework.TestCase;
+
+/**
+ * A JUnit test case class.
+ * Every method starting with the word "test" will be called when running
+ * the test with JUnit.
+ */
+public class CardTest extends TestCase {
+
+  /**
+   * A test method.
+   * (Replace "X" with a name describing the test.  You may write as
+   * many "testSomething" methods in this class as you wish, and each
+   * one will be called when running JUnit over this class.)
+   */
+  public void testCardQueeries()
+  {
+    Card card1 = new Card(3, 2, 2, 1);
+    //a card with numbers between 1 and 3
+    assertEquals(3, card1.getQuantity());
+    assertEquals(2, card1.getColor());
+    assertEquals(2, card1.getShading());
+    assertEquals(1, card1.getShape());
+
+    Card card2 = new Card(4, 5, 6, 7);
+   //a card with numbers greater than 3
+    assertEquals(1, card2.getQuantity());
+    assertEquals(2, card2.getColor());
+    assertEquals(3, card2.getShading());
+    assertEquals(1, card2.getShape());
+
+    Card card3 = new Card(0, -1, -2, -3);
+    //a card with numbers lower than 1
+    assertEquals(3, card3.getQuantity());
+    assertEquals(2, card3.getColor());
+    assertEquals(1, card3.getShading());
+    assertEquals(3, card3.getShape());
+  }
+
+  public void testCardEquals()
+  {
+   Card card1 = new Card(1, 2, 3, 1);
+   Card card2 = new Card(1, 2, 3, 1);
+   Card card3 = new Card(4, 5, 6, 7);
+   Card card4 = new Card(-2, -1, 0, -5);
+   Card card5 = new Card(1, 1, 1, 1);
+
+   assertEquals(true, card1.equals(card2));
+   assertEquals(true, card1.equals(card3));
+   assertEquals(true, card1.equals(card4));
+   assertEquals(true, card2.equals(card3));
+   assertEquals(true, card2.equals(card4));
+   assertEquals(true, card3.equals(card4));
+
+   assertEquals(false, card5.equals(card1));
+   assertEquals(false, card5.equals(card2));
+   assertEquals(false, card5.equals(card3));
+   assertEquals(false, card5.equals(card4));
+
+  }
+
+  public void testCardString()
+  {
+    Card card1 = new Card(1, 1, 1, 2);
+    Card card2 = new Card(3, 2, 3, 2);
+    Card card3 = new Card(4, 5, 6, 7);
+    Card card4 = new Card(0, -1, -2, -3);
+
+    assertEquals("1ROD", card1.toString());
+    assertEquals("3GSD", card2.toString());
+    assertEquals("1GSO", card3.toString());
+    assertEquals("3GOS", card4.toString());
+  }
+
+  public void testCardSet()
+  {
+   Card card1 = new Card(1, 1, 1, 1);
+   Card card2 = new Card(2, 1, 1, 1);
+   Card card3 = new Card(3, 1, 1, 1);
+   Card card4 = new Card(2, 2, 2, 2);
+   Card card5 = new Card(3, 3, 3, 3);
+
+   assertEquals(true, card1.isSet(card2, card3));
+   assertEquals(true, card1.isSet(card4, card5));
+   assertEquals(false, card1.isSet(card2, card4));
+   assertEquals(true, card3.isSet(card2, card1));
+   assertEquals(true, card2.isSet(card1, card3));
+   assertEquals(false, card2.isSet(card1, card4));
+   assertEquals(false, card4.isSet(card1, card2));
+   assertEquals(false, card4.isSet(card3, card2));
+
+  }  
+}

src/Deck.java

@@ -2,14 +2,55 @@
 import java.io.FileReader;
 import java.util.StringTokenizer;
 import java.util.ArrayList;
+import java.util.Collections;
 
 public class Deck {
-  // Implement the rest of this class yourself
+  private ArrayList<Card> cards;
+  private int nextCardIndex;
 
-  public Deck(String filename) {
+  public Deck()
+  {
     cards = new ArrayList<Card>(81);
+    nextCardIndex = 0;
 
-    try {
+    for (int i = 1; i < 4; i++)
+    {
+      for (int j = 1; j < 4; j++)
+      {
+        for (int k = 1; k < 4; k++)
+        {
+          for (int l = 1; l < 4; l++)
+          {
+            cards.add(new Card(i, j, k, l));
+          }
+        }
+      }
+    }
+
+    Collections.shuffle(cards);
+  }
+
+
+  public boolean hasNext()
+  {
+   return nextCardIndex < cards.size(); 
+  }
+
+  public Card getNext()
+  {
+   if (hasNext() == false)
+     return null;
+
+   nextCardIndex += 1;
+   return cards.get(nextCardIndex - 1);
+  }
+
+  public Deck(String filename)
+  {
+    cards = new ArrayList<Card>(81);
+
+    try 
+    {
       String line;
       BufferedReader infile = new BufferedReader(new FileReader(filename));
       int position = 0;
@@ -38,7 +79,8 @@ public Deck(String filename) {
         nextCardIndex = 0;
       }
     }
-    catch(Exception e) {
+    catch(Exception e)
+    {
       throw new RuntimeException("Error while reading file: " + e.toString());
     }
   }

src/DeckNoSetsFirstTable.txt

@@ -0,0 +1,12 @@
+1 1 1 1 
+1 1 1 2
+1 1 2 1
+1 1 2 3
+1 2 1 1
+1 2 3 1
+2 1 1 1 
+2 3 1 3
+3 3 2 1
+3 1 2 3
+3 3 3 3 
+3 2 1 2

src/DeckTest.java

@@ -0,0 +1,75 @@
+import junit.framework.TestCase;
+
+/**
+ * A JUnit test case class.
+ * Every method starting with the word "test" will be called when running
+ * the test with JUnit.
+ */
+public class DeckTest extends TestCase {
+
+
+  /**
+   * A test method.
+   * (Replace "X" with a name describing the test.  You may write as
+   * many "testSomething" methods in this class as you wish, and each
+   * one will be called when running JUnit over this class.)
+   */
+  public void testDeckCreation()
+  {
+    Deck deck = new Deck();
+    int i = 0;
+
+    while (deck.hasNext())
+    {
+     deck.getNext();
+     i += 1;
+    }
+
+    assertEquals(81, i);
+  }
+
+   public void testCostumDeckCreation()
+  {
+     Deck deck = new Deck("DeckTester.txt");
+     Card card1 = new Card(1, 1, 1, 1);
+     Card card2 = new Card(1, 1, 1, 2);
+     Card card3 = new Card(1, 1, 1, 3);
+     Card card4 = new Card(1, 1, 2, 1);
+
+     assertEquals(true, deck.hasNext());
+     assertEquals(true, deck.getNext().equals(card1));
+
+     assertEquals(true, deck.hasNext());
+     assertEquals(true, deck.getNext().equals(card2));
+
+     assertEquals(true, deck.hasNext());
+     assertEquals(true, deck.getNext().equals(card3));
+
+     assertEquals(true, deck.hasNext());
+     assertEquals(true, deck.getNext().equals(card4));
+
+     assertEquals(false, deck.hasNext());
+     assertEquals(null, deck.getNext());
+  }
+
+   public void testEmptyDeck()
+   {
+    Deck deck = new Deck("emptydeck.txt");
+
+    assertEquals(false, deck.hasNext());
+    assertEquals(null, deck.getNext());
+   }
+
+   public void testOneDeck()
+   {
+    Deck deck = new Deck("onedeck.txt");
+    Card card = new Card(1, 1, 1, 1);
+
+    assertEquals(true, deck.hasNext());
+    assertEquals(true, deck.getNext().equals(card));
+
+    assertEquals(false, deck.hasNext());
+    assertEquals(null, deck.getNext());
+   }
+}
+

src/DeckTester.dat

@@ -0,0 +1,4 @@
+1 1 1 1
+1 1 1 2
+1 1 1 3
+1 1 2 1

src/DeckTester.txt

@@ -0,0 +1,4 @@
+1 1 1 1
+1 1 1 2
+1 1 1 3
+1 1 2 1

src/FullTableAndSets.txt

@@ -0,0 +1,15 @@
+1 1 1 1 
+1 1 1 2
+1 1 1 3
+2 2 2 2 
+3 3 3 3
+2 2 2 3
+2 2 2 1
+3 3 3 2
+3 3 3 1
+2 1 2 2
+3 2 2 1
+3 1 1 3
+1 2 2 3
+3 2 1 1 
+3 1 2 3