How to randomly fill two-dimensional array in a loop that ends when array is filled

I've taken this piece of code out of my bigger project, basically I want to pick a random point within the array and remember that it's been picked (by setting its value to 1) and repeat it till the whole array is filled. What's wrong with this code? Why doesn't it fill every single field?

    //initialize
    int arraysizex = 5;
    int arraysizey = 5;
    int x = 0, y = 0;
    int filledcount = 0;
    int[][] array = new int[arraysizex][arraysizey];

    //fill
    for (int i = 0; i < arraysizex * arraysizey; i++) {
        do {
            x = (int) (Math.random() * arraysizex);
            y = (int) (Math.random() * arraysizey);
            if (array[x][y] == 0) {
                array[x][y] = 1;
            //do something
            }
        } while (array[x][y] == 0);
    }

    //display
    for (int i = 0; i < arraysizey; i++) {
        System.out.println();
        for (int j = 0; j < arraysizex; j++) {
            System.out.print(array[j][i]);
            if (array[j][i] == 1) {
                filledcount++;
            }
        }
    }
    System.out.print("\n" + filledcount+"\n");