Java输入和输出数组（加逗号）

 import java.util.Scanner;

 public class Demo01 {

     public static void main(String[] args) {

         Scanner sc = new Scanner(System.in);

         int n=sc.nextInt();

         String str = sc.next().toString();

         String[] arr = str.split(",");

         int[] b = new int[n];

         for (int j = 0; j < n; j++) {

            b[j] = Integer.parseInt(arr[j]);

             if(j!=n-1)

             System.out.print(b[j] + ",");

             else

             System.out.println(b[j]);

         }

                 System.out.print(arr[0]);

             for(int i=1;i<arr.length;i++){

                 System.out.print(","+arr[i]);

         }
           sc.close();

     }

 }