Error from sudoku class

[hongi]

This is my code about SUDOKU
I got this error and don't know what it is.

Exception in thread "main" java.lang.NullPointerException
	at Sudoku.ForcedSet(test.java:265)
	at test.main(test.java:66)

  public class test
{
   public static void main(String[] args)
   {
      SudCell sud1, sud2, sud3;
      
      sud1 = new SudCell();
      sud2 = new SudCell();
      sud3 = new SudCell();

      if ( !sud1.ForcedSet(10) )
         System.out.print( "Bad 10\n" );

      if ( !sud2.ForcedSet(-1) )
         System.out.print( "Bad -1\n" );
      if ( !sud3.RuleOut(50) )
         System.out.print( "Bad 50\n" );

      System.out.print( "A: " + sud1.ToString() + "\n" );
      System.out.print( "B: " + sud2.ToString() + "\n" );
      System.out.print( "C: " + sud3.ToString() + "\n" );
      System.out.print( "\n" );

      System.out.print( "D: " + sud1.ToStringReveal() + "\n" );
      System.out.print( "E: " + sud2.ToStringReveal() + "\n" );
      System.out.print( "F: " + sud3.ToStringReveal() + "\n" );
      System.out.print( "\n" );

      sud1.ForcedSet(3);
      sud2.ForcedSet(9);
      sud3.RuleOut(0);
      sud3.RuleOut(2);
      sud3.RuleOut(4);
      sud3.RuleOut(6);
      sud3.RuleOut(8);
      
      System.out.print( sud1.ToString() + "\n" );
      System.out.print( sud2.ToString() + "\n" );
      System.out.print( sud3.ToString() + "\n" );
      System.out.print( "\n" );

      System.out.print( sud1.ToStringReveal() + "\n" );
      System.out.print( sud2.ToStringReveal() + "\n" );
      System.out.print( sud3.ToStringReveal() + "\n" );
      System.out.print( "\n" );

      sud1.Complete();
      sud2.Complete();
      sud3.Complete();

      System.out.print( sud1.IsCompleted() + " " + sud2.IsCompleted() + " "
         + sud3.IsCompleted() + "\n" );
      System.out.print( sud1.ValuePresent(1) + " " 
            + Boolean.toString(sud1.ValuePresent(2))
            + " " + Boolean.toString(sud1.ValuePresent(3)) + "\n" );
      System.out.print( Boolean.toString(sud3.ValuePresent(1)) 
            + " " + Boolean.toString(sud3.ValuePresent(2))
            + " " + Boolean.toString(sud3.ValuePresent(3)) + "\n" );
      
      
      Sudoku puzzle;

      puzzle = new Sudoku();
      
      // set some values in the matrix, attempting illegal
      puzzle.ForcedSet(3, 4, 5);
      puzzle.ForcedSet(7, 1, 3);
      puzzle.ForcedSet(9, 2, 6);
      for (int k = -1; k < 12; k++)
         if ( !puzzle.ForcedSet(k, k, k) )
            System.out.println( "Could not set " + k);

      System.out.print( "\n ------------- first basic ------------- \n");
      puzzle.Display(false);

      System.out.print( "\n ------------- then revealed ------------- \n");
      puzzle.Display(true);
      System.out.print( "\n" );;

      for (int row = Sudoku.MIN_VAL; row <= Sudoku.MAX_VAL ; row++)
         for (int col = Sudoku.MIN_VAL; col <= Sudoku.MAX_VAL ; col++)
         {
            // rule out 2 through 8 in all places except middle row and col
            if ( row == 5 || col == 5 )
               continue;
             for (int k = 2; k <= 8; k++)
               puzzle.RuleOut(row, col, k);
         }

      System.out.print( "\n ---------- after massive rule-outs ---------- \n");
      puzzle.Display(true);
   }
}

class Sudoku
{
   static final int MIN_VAL = SudCell.MIN_VAL;
   static final int MAX_VAL = 9;
   static final int NUM_VALS = 9;
   static final int SQRT_NUM_VALS = 3;
   static final int NOT_FINAL_YET = -1;
   
   SudCell suds[][] = new SudCell[NUM_VALS][NUM_VALS];
   
   public Sudoku()
   {
      
   }
   void Display(boolean reveal)
   {
      String output;
      int levlinecount = 0, sepcount = 0, divider = 0, divideend = 0;
      if (reveal == false)
      {
         for (int x=0;x<MAX_VAL;x++)
         {
            for (int y=0;y<MAX_VAL;y++)
            {
               output = suds[x][y].ToString();
               System.out.print(output);
               sepcount++;
               if (sepcount > 2)
               {
                  sepcount = 0;
                  if (levlinecount < 2)
                  {
                     System.out.print ("|");
                     levlinecount++;
                  }
                  else
                  {
                     levlinecount = 0;
                     if (divider < 2)
                     {
                        System.out.print( "\n" );
                        divider++;
                     }
                     else
                     {
                        if (divideend < 2)
                        {
                           System.out.print( "\n" + "---------------" +
                                 "--------------" +"\n" );
                           divider = 0;
                           divideend++;
                        }
                     }
                  }
               }
            }
         }
      }
      else
      {
         for (int x=0;x<MAX_VAL;x++)
         {
            for (int y=0;y<MAX_VAL;y++)
            {
               output = suds[x][y].ToStringReveal();
               System.out.print(output);
               sepcount++;
               if (sepcount > 2)
               {
                  sepcount = 0;
                  if (levlinecount < 2)
                  {
                     System.out.print ("|");
                     levlinecount++;
                  }
                  else
                  {
                     levlinecount = 0;
                     if (divider < 2)
                     {
                        System.out.print( "\n" );
                        divider++;
                     }
                     else
                     {
                        if (divideend < 2)
                        {
                           System.out.print( "\n" + "---------------" +
                                 "--------------" +"\n" );
                           divider = 0;
                           divideend++;
                        }
                     }
                  }
               }
            }
         }
      }
   }
   
   
   public int GetFinalValue(int row, int col)
   {
      return suds[row-1][col-1].GetFinalValue();
   }
   public boolean IsCompleted(int row, int col)
   {
      return suds[row-1][col-1].IsCompleted();
      
   }
   public boolean ValuePresent(int row, int col, int val)
   {
      return suds[row-1][col-1].ValuePresent(val);
   }
   public int NumRemainingVals(int row, int col)
   {
      return suds[row-1][col-1].NumRemainingVals();
   }
   public int NumRemainingValsTotal()
   {
      int total = 0;
      for (int x=0;x<MAX_VAL;x++)
      {
         for (int y=0;y<MAX_VAL;y++)
         {
            total += suds[x][y].GetFinalValue();
         }
      }
      return total;
   }
   public boolean AllSingletons()
   {
      boolean answer = true;
      for (int x=0;x<MAX_VAL;x++)
      {
         for (int y=0;y<MAX_VAL;y++)
         {
            if (NOT_FINAL_YET == suds[x][y].GetFinalValue())
               answer = false;
         }
      }
      return answer;
   }
   public boolean EmptyCellFound()
   {
      boolean answer = false;
      for (int x=0;x<MAX_VAL;x++)
      {
         for (int y=0;y<MAX_VAL;y++)
         {
            if (0 == suds[x][y].NumRemainingVals())
               answer = true;
         }
      }
      return answer;
   }
   
   public void SetToBlank()
   {
      for (int x=0;x<MAX_VAL;x++)
      {
         for (int y=0;y<MAX_VAL;y++)
         {
            suds[x][y].SetToBlank();
         }
      }
   }
   public boolean ForcedSet(int row, int col, int val)
   {
      return suds[row-1][col-1].ForcedSet(val);
   }
   public boolean Complete(int row, int col)
   {
      return suds[row-1][col-1].Complete();
   }
   public boolean RuleOut(int row, int col, int val)
   {
      return suds[row-1][col-1].RuleOut(val);
   }
   public boolean SoftSet(int row, int col, int val)
   {
      return suds[row-1][col-1].SoftSet(val);
   }
   
   boolean Validate(int val)
   {
      if (val < MIN_VAL || val > MAX_VAL)
         return false;
      else
         return true;
   }
   boolean  IndexValidate(int n)
   {
      if (n < 0 || n > NUM_VALS-1)
         return false;
      else
         return true;
   }
}

class SudCell
{
   private boolean digits[] = new boolean [9];
   private boolean completed;
   private int FinalValue;
   private int NumRemainingVals;
   private String String_Val,String_RVL;
   
   static final int MIN_VAL = 1;
   static final int MAX_VAL = 9;
   static final int NUM_VALS = 9;
   static final int SQRT_NUM_VALS = 3;
   static final int NOT_FINAL_YET = -1; 
   
   public SudCell()
   {
      for (int k=0;k<9;k++)
      {
         digits[k] = true;
      }
      completed = false;
   }

   public String ToString()
   {
      String output;
      int boolcount = 0;
      int whichdigit = 0;
      for (int x=0;x<9;x++)
      {
         if (digits[x] == true)
         {
            whichdigit = x;
            boolcount++;
         }
      }
      if (boolcount > 1 || boolcount < 1)
         output = " - ";
      else
      {
         whichdigit++;
         output = Integer.toString(whichdigit);
         output = " " + output + " ";
      }

      return output;
   }
   
   public String ToStringReveal()
   {
      String_RVL = "";
      if (digits[0] == true && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         String_RVL = "1";
      }
      else if  (digits[0] == false && digits[1] == true && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         String_RVL = "2";
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == true
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         String_RVL = "3";
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == true && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         String_RVL = "4";
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == true && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         String_RVL = "5";
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == true
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         String_RVL = "6";
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == true && digits[7] == false && digits[8] == false)
      {
         String_RVL =  "7";
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == true && digits[8] == false)
      {
         String_RVL = "8";
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == true)
      {
         String_RVL = "9";
      }
      else
      {
         for (int k=0;k<9;k++)
         {
            if (digits[0] = true)
               k=k+1;
            String_RVL = String_RVL +(k);
         }
      }
      return String_RVL = " "+String_RVL+" ";
   }

   public int GetFinalValue()
   {
      if (digits[0] == true && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         FinalValue = 1;
      }
      else if  (digits[0] == false && digits[1] == true && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         FinalValue = 2;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == true
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         FinalValue = 3;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == true && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         FinalValue = 4;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == true && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         FinalValue = 5;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == true
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         FinalValue = 6;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == true && digits[7] == false && digits[8] == false)
      {
         FinalValue = 7;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == true && digits[8] == false)
      {
         FinalValue = 8;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == true)
      {
         FinalValue = 9;
      }
      else
         FinalValue = NOT_FINAL_YET;
      return FinalValue;
   }
   public boolean IsCompleted()
   {
      return completed;
   }
   public boolean ValuePresent(int val)
   {
      if (digits[val-1] == true)
         return true;
      else
         return false;
   }
   public int NumRemainingVals()
   {
      int boolcount = 0;
      for (int x=0;x<9;x++)
      {
         if (digits[x] == true)
            boolcount++;
      }
      return boolcount;
   }
   
   public void SetToBlank()
   {
      for (int x=0;x<9;x++)
      {
         digits[x] = true;
      }
   }
   
   public boolean ForcedSet(int val)
   {  
      if(val < MIN_VAL || val > MAX_VAL)
         return false;
      else
      {
      for (int x=0;x<9;x++)
      {
         digits[x] = false;
      }
      digits[val-1] = true;
      return true;
      }
   }
   public boolean Complete()
   {

      if (digits[0] == true && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == true && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == true
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == true && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == true && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == true
            && digits[6] == false && digits[7] == false && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == true && digits[7] == false && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == true && digits[8] == false)
      {
         completed = true;
         return true;
      }
      else if  (digits[0] == false && digits[1] == false && digits[2] == false
            && digits[3] == false && digits[4] == false && digits[5] == false
            && digits[6] == false && digits[7] == false && digits[8] == true)
      {
         completed = true;
         return true;
      }
      else
         return false;
   }
   public boolean RuleOut(int val)
   {
      if (val == 1)
      {
         digits[0] = false;
         return false;
      }
      else if (val == 2)
      {
         digits[1] = false;
         return false;
      }
      else if (val == 3)
      {
         digits[2] = false;
         return false;
      }
      else if (val == 4)
      {
         digits[3] = false;
         return false;
      }
      else if (val == 5)
      {
         digits[4] = false;
         return false;
      }
      else if (val == 6)
      {
         digits[5] = false;
         return false;
      }
      else if (val == 7)
      {
         digits[6] = false;
         return false;
      }
      else if (val == 8)
      {
         digits[7] = false;
         return false;
      }
      else if (val == 9)
      {
         digits[8] = false;
         return false;
      }
      else
      return false;
   }
   public boolean SoftSet(int val)
   {
      for (int k=0;k<9;k++)
      {
         for (int l=1;l<10;l++)
         {
            if (val == l)
            {
               digits[k] = true;
            }
         }
      }
      return false;
   }
   public boolean Validate(int val)
   {
      if (val >= MIN_VAL && val <= MAX_VAL)
      {
         return true;
      }
      else
         return false;
   }
}

[[RaIdEn]]

did you try debugging?

[Fubarable]

You're trying to dereference an object which is null on the line that the NPE error is thrown. There's only one object that this can be attributed to,... so you must ask yourself, when do you ever initialize the items in this array?

[hongi]

Why i can't just code like this
Insert in to Sudoku class

    public Sudoku()
   {
      SetToBlank();
   }

[Fubarable]

Crosspost: Error from sudoku class (Beginning Java forum at JavaRanch)

OP, please read up on the proper etiquette for notifying us about cross-posts here: JavaRanch - Be Forthright When Cross Posting To Other Sites

Your cooperation on this would be greatly appreciated (and the converse is true!).