随机数的算法

public void test(){
List<Integer> list = new ArrayList<Integer>();

for(int i = 1; i <= 6; i++){
list.add(i);
}

Collections.shuffle(list);

for(Integer i : list){
System.out.println(i);
}
}

public void test_2(){
int a[] = new int[6];
for (int i = 0; i < a.length; i++) {
a[i] = (int) (Math.random() * 6) + 1;
for (int k = 0; k < i; k++) {
if (a[i] == a[k]) {
i--;
continue;
}
}
}
System.out.println(Arrays.toString(a));

}