如何使我的Rowsum方法使用多线程工作

Question

我已经编码到从用户提供的txt文件中打印出数组的程度。我正在尝试运行我专门为将txt文件放入数组后的行求和而创建的线程，但是现在我被卡住了，因为我无法获得rowSum线程来实际对行求和。我发布了整个文件只是为了确保我提供了足够的信息以帮助他人。

public class Assignment1  {

public static void main(String[] args) throws FileNotFoundException {
 // TODO Auto-generated method stub
    rowSum t1 = new rowSum();


    t1.start();     


 System.out.println("Enter txt file for summation.");

 Scanner scan = new Scanner(System.in);
 String txtFile = scan.nextLine();
 File file = new File(txtFile);

 int[][] matrix = new int[1000][1000];
 int x=0, y=0;
 try
        {
 BufferedReader in = new BufferedReader(new FileReader(file)); //reading files in specified directory
  String line;
 while ((line = in.readLine()) != null) //file reading
 {
    String[] values = line.split("  ");
    for (String str : values )
    {
       int str_double = (int) Double.parseDouble(str);
       matrix[x][y]=str_double;
       System.out.print(matrix[x][y] + " ");
       y=y+1; //you have inserted a value to the former y, need to increment
    }
    x=x+1; // finished the row, need to increment the row number
    System.out.println("");




    //in.close();
 }
// int rowSize = matrix.length;
// int columnSize = matrix[0].length;
// System.out.println("rows=" + rowSize + "cols=" + columnSize);


        }
 catch( IOException ioException ) {}




}


class rowSum implements Runnable{
    int c[][];

    public rowSum(int c[][]) {

         this. c = matrix[][];

        }

    public void start() {
        // TODO Auto-generated method stub

    } 
    }


    public void run() {
        int i,j,sum = 0; 

        System.out.print( "\nFinding Sum of each row:\n\n"); 

        // finding the row sum 
        for (i = 0; i < 4; ++i) { 
            for (j = 0; j < 4; ++j) { 

                // Add the element 
                sum = sum + matrix[i][j]; 
            } 

            // Print the row sum 
            System.out.println( "Sum of the row "
                + i + " = " + sum); 


            // Reset the sum 
            sum = 0; 

    }
}

}



The program crashes on me. I think my problem is passing the matrix to the thread but I could be wrong.