数组排序，数组转化为List，通过List的sort排序， 升序o1-o2
数组排序
int[] arr = {3, 4, 5, 1, 2, 6, 7, 9, 8};
Integer[] arr2 = new Integer[arr.length];
for(int i=0; i<arr.length; i++) {
arr2[i] = arr[i];
}
List<Integer> list = Arrays.asList(arr2);
list.sort(new Comparator<Integer>() {
@Override
public int compare(Integer o1, Integer o2) {
return o1-o2;
}
});
for(Integer tmp: list) {
System.out.print(tmp +" ");
}