java - How to generate random number and export it as JSON? -

i planning generate random number , export json using json-simple. have following code

public class main implements jsonaware{      private final int data;      public main(int data){         this.data = data;     }       public string tojsonstring(){         stringbuffer sb = new stringbuffer();          sb.append("[");          sb.append(data);          sb.append("]");         sb.append(",");           return sb.tostring();     }      public static void main(string[] args){          jsonarray da = new jsonarray();           random generator = new random();         int [][] grid;          grid = new int[128][14];          (int row = 0; row < 128; row++){             (int col = 0; col < 14; col++){                 grid[row][col] = generator.nextint(100); //                da.add("%d",grid[row][col]);                 da.add(grid[row][col]);             } //            system.out.println();         }         system.out.println(da);      } 

this prints following:

[9,62,6,60,29,28,59,56,67,61,53,23,22,31,15,96,94,85,65,94,15,7,91,...]

but trying print

[9,62,6,60,29,28,59,56,67,61,53,23,22,31,15,96,94,85,65,94,15,7,91,...], [68,48,40,44,47,85,8,43,17,78,35,7,77,26,80,34,19,47,17,0,59,5,79,...], . . . 

can tell me how split row column?

as far understood problem, want 128 rows separate jsonarray i.e. 1 row = 1 jsonarray.
:

public static void main(string[] args){      jsonarray jarray = new jsonarray();      random generator = new random();     int [][] grid;      grid = new int[128][14];      (int row = 0; row < 128; row++){         jsonarray da = new jsonarray();         (int col = 0; col < 14; col++){             grid[row][col] = generator.nextint(100);             da.add(grid[row][col]);         }         jarray.add(da);     }     system.out.println(jarray);  }