много чище просто использовать Collections::shuffle
List<Integer> filledArray = fillArray();
for (int i = 0; i < 10; i++)
{
Collections.shuffle(filledArray);
System.out.println(filledArray);
}
выход
[7, 0, 3, 5, 2, 1, 9, 10, 4, 8, 6]
[3, 7, 6, 0, 1, 8, 4, 5, 9, 2, 10]
[3, 7, 2, 4, 9, 10, 0, 8, 5, 1, 6]
[8, 1, 0, 7, 4, 2, 3, 6, 10, 9, 5]
[2, 3, 8, 4, 5, 10, 9, 1, 6, 7, 0]
[10, 2, 0, 1, 5, 8, 7, 6, 9, 3, 4]
[1, 5, 0, 9, 2, 4, 6, 8, 10, 7, 3]
[2, 8, 1, 9, 7, 3, 5, 6, 10, 4, 0]
[9, 1, 2, 4, 6, 8, 0, 3, 10, 5, 7]
[4, 5, 2, 3, 10, 9, 6, 8, 0, 1, 7]