JAVA-二维数组元素打乱

package com.itheima;

import java.util.Random;

public class shuzu07 {
    public static void main(String[] args) {
        int [][] arr={{1,2,3},{4,5,6},{7,8,9}};
        Random a=new Random();
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {

                int x= a.nextInt(arr.length);
                int y= a.nextInt(arr[x].length);
                int temp =arr[i][j];
                arr[i][j]=arr[x][y];
                arr[x][y]=temp;
            }
        }
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                System.out.print(arr[i][j]+" ");

            }
            System.out.println();
        }
    }
}

执行结果
6 1 7 
9 3 2 
4 8 5 

Process finished with exit code 0