배열 역순으로 정렬하기

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Collections;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String n = br.readLine();
        String[] arr = n.split("");
        Integer[] arrInt = new Integer[arr.length];
        for (int i = 0; i < arr.length; i++) {
            arrInt[i] = Integer.parseInt(arr[i]);
        }
        Arrays.sort(arrInt, Collections.reverseOrder());
        for (Integer x : arrInt) System.out.print(x);
    }
}

 

꼭 기본형으로 지정해주어야 함. 

int[] → Integer[]