import java.util.Random;        public class RandomSort {        private Random random = new Random();        //数组大小        private static final int SIZE = 10;        //要重排序的数组        private int[] positions = new int[SIZE];                public RandomSort() {            for(int index=0; index<SIZE; index++) {                //初始化数组，以下标为元素值                positions[index] = index;            }            //顺序打印出数组的值            printPositions();      }                //重排序        public void changePosition() {            for(int index=SIZE-1; index>=0; index--) {                //从0到index处之间随机取一个值，跟index处的元素交换                exchange(random.nextInt(index+1), index);            }            printPositions();        }                //交换位置        private void exchange(int p1, int p2) {            int temp = positions[p1];            positions[p1] = positions[p2];            positions[p2] = temp;  //更好位置      }                //打印数组的值        private void printPositions() {            for(int index=0; index<SIZE; index++) {                System.out.print(positions[index]+" ");                     }            System.out.println();        }            public static void main(String[] args) {            RandomSort rs = new RandomSort();            rs.changePosition();            rs.changePosition();            rs.changePosition();        }    }