Trying to sort a multidimensional array

Question

I'm in a Java class and am trying to create an inventory program. It doesn't have to store the data to a file, just create and sort arrays to display the information sorted. I'm using golfing discs as my inventory and was able to get the arrays stuffed and printed out how I liked. Now I just need to figure out how to sort the MasterArray by the disc name column (MasterArray[ ][2]) and, if those are the same, the SKU column (MasterArray[ ][0]).
The error I'm getting is:
DiscInventoryCall.java:134: non-static variable this cannot be referenced from a
static context
Arrays.sort( MasterArray, new DiscComparator() );
^
Note: DiscInventoryCall.java uses unchecked or unsafe operations.
Here is my code:
// Disc Inventory Program
import java.util.*;
public class DiscInventoryCall
     // start main method
     public static void main( String args[] )
    // create Scanner to grab input
    Scanner input = new Scanner( System.in );
          // declare variables
          String sendDiscSKU;
          String sendDiscBrand;
          String sendDiscName;
          String sendDiscType;
          int sendDiscWeight = 0;
          double sendDiscPrice = 0.00;
          int sendDiscCount = 0;
          double InventoryTotal = 0.00;
          int AllDone = 0;
          int Counter = 0;
          String DiscStop = "done"; // string value to stop the program
          int Weight1 = 0;
          int Weight2 = 0;
          int Price1 = 0;
          int Price2 = 0;
          int Count1 = 0;
          int Count2 = 0;
          int Value1 = 0;
          int Value2 = 0;
          // declare array variables
          String MasterArray[][] = new String[100][12];
          Double DoubleArray[][] = new Double[100][2];
          int IntArray[][] = new int[100][2];
          System.out.print( "Enter Disc SKU (enter \"done\" when finished): " );
          sendDiscSKU = input.nextLine();
          if ( sendDiscSKU.equals(DiscStop) )
         AllDone = 1;
    } // bypass while loop
          // begin while loop
          while ( AllDone == 0 )
               System.out.print( "Enter Disc Brand: " );
               sendDiscBrand = input.nextLine();
               System.out.print( "Enter Disc Name: " );
               sendDiscName = input.nextLine();
               System.out.print( "Enter Disc Type: " );
               sendDiscType = input.nextLine();
               System.out.print( "Enter Disc Weight (in grams): " );
               sendDiscWeight = input.nextInt();
               System.out.print( "Enter Disc Price: $" );
               sendDiscPrice = input.nextDouble();
               System.out.print( "Enter Disc Count: " );
               sendDiscCount = input.nextInt();
               // instantiate DiscInventory object
               DiscInventory Disc = new DiscInventory( sendDiscSKU, sendDiscBrand, sendDiscName, sendDiscType, sendDiscWeight, sendDiscPrice, sendDiscCount );
               // get Disc data
               //System.out.println();
               //System.out.println( "Disc information summary:");
               //System.out.println();
               //System.out.printf( "%15s %s\n", "Disc SKU:", Disc.getDiscSKU() );
               //System.out.printf( "%15s %s\n", "Disc Brand:", Disc.getDiscBrand() );
               //System.out.printf( "%15s %s\n", "Disc Name:", Disc.getDiscName() );
               //System.out.printf( "%15s %s\n", "Disc Type:", Disc.getDiscType() );
               //System.out.printf( "%15s %d grams\n", "Disc Weight:", Disc.getDiscWeight() );
               //System.out.printf( "%15s $%.2f\n", "Disc Price:", Disc.getDiscPrice() );
               //System.out.printf( "%15s %d\n", "No. Available:", Disc.getDiscCount() );
               System.out.printf( "%15s $%.2f\n\n", "Total Value:", Disc.DiscValue() );
               // System.out.printf( "\n%s:\n\n%s\n", "Disc information obtained by toString", Disc );
               // Add total inventory values
               InventoryTotal = InventoryTotal + Disc.DiscValue();
               System.out.printf( "%15s %.2f\n", "Total Inventory Value:", InventoryTotal );
               // Stuff the array
               MasterArray[Counter][0] = Disc.getDiscSKU();
               MasterArray[Counter][1] = Disc.getDiscBrand();
               MasterArray[Counter][2] = Disc.getDiscName();
               MasterArray[Counter][3] = Disc.getDiscType();
               MasterArray[Counter][4] = Integer.toString(Counter);
               MasterArray[Counter][5] = "0";        
               MasterArray[Counter][6] = Integer.toString(Counter);
               MasterArray[Counter][7] = "0";        
               MasterArray[Counter][8] = Integer.toString(Counter);
               MasterArray[Counter][9] =  "1";
               MasterArray[Counter][10] = Integer.toString(Counter);
               MasterArray[Counter][11] =  "1";
               DoubleArray[Counter][0] = Disc.getDiscPrice();
               DoubleArray[Counter][1] = Disc.DiscValue();
               IntArray[Counter][0] = Disc.getDiscWeight();
               IntArray[Counter][1] = Disc.getDiscCount();
               Counter++;
               System.out.print( "Enter Disc SKU (enter \"done\" when finished): " );
               input.nextLine();
               sendDiscSKU = input.nextLine();
         if ( sendDiscSKU.equals(DiscStop) )
              AllDone = 1;
             } // stop while loop
          } // end while loop
          Arrays.sort( MasterArray, new DiscComparator() );
          System.out.printf( "%-11s %-6s %-6s %-15s %-5s %-10s %-6s %-10s\n", "SKU", "Brand", "Name", "Type", "Weight", "Price", "Count", "Value" );
          for ( int Countup = 0; Countup < Counter; Countup++ )
               Weight1 = Integer.parseInt(MasterArray[Countup][4]);
               Weight2 = Integer.parseInt(MasterArray[Countup][5]);
               Price1 = Integer.parseInt(MasterArray[Countup][6]);
               Price2 = Integer.parseInt(MasterArray[Countup][7]);
               Count1 = Integer.parseInt(MasterArray[Countup][8]);
               Count2 = Integer.parseInt(MasterArray[Countup][9]);
               Value1 = Integer.parseInt(MasterArray[Countup][10]);
               Value2 = Integer.parseInt(MasterArray[Countup][11]);
               System.out.printf( "%-11s %-6s %-6s %-15s %-6d $%-8.2f %5d $%-9.2f\n",
               MasterArray[Countup][0],
               MasterArray[Countup][1],
               MasterArray[Countup][2],
               MasterArray[Countup][3],
               IntArray[Weight1][Weight2],
               DoubleArray[Price1][Price2],
               IntArray[Count1][Count2],
               DoubleArray[Value1][Value2] );
          System.out.printf( "\n\nThank you for using this program. \nYour total inventory value is: $%.2f\n", InventoryTotal );
     } // end main method
     // begin sorting method
     class DiscComparator implements Comparator
          public int compare( Object obj1, Object obj2 )
               int result = 0;
               String[] str1 = (String[]) obj1;
               String[] str2 = (String[]) obj2;
               // sort on name of disc
               if (( result = str1[2].compareTo(str2[2])) == 0 )
                    // if disc names are the same, sort on sku
                    result = str1[0].compareTo(str2[1]);
               return result;
     }     // end sorting method
} // end class DiscInventoryCallAny help on what I'm doing wrong would be appreciated.

Answer 1

I'm pretty new to OOP and, to be honest, wouldn't know what parts could be broken into separate objects.
There are some extra lines in there I could have removed (commented out) but forgot to do so before I posted it.
So when it shows:
DiscInventoryCall.java:134: non-static variable this cannot be referenced from a
static context
Arrays.sort( MasterArray, new DiscComparator() );
^
Is that saying the DiscComparator() is a non-static variable? or the MasterArray?