나이순 정렬 [JAVA]

public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(bf.readLine());
        String[][] arr = new String[n][2];
        for (int i = 0; i < n; i++){
            StringTokenizer st = new StringTokenizer(bf.readLine());
            arr[i][0] = st.nextToken();
            arr[i][1] = st.nextToken();
        }

        Arrays.sort(arr, (o1, o2) -> {
            if(o1[0] == o2[0]){
                return compare(o1[1],o2[1]);
            }else{
                return Integer.compare(Integer.parseInt(o1[0]), Integer.parseInt(o2[0]));
            }
        });

        for (String[] i : arr){
            System.out.println(i[0] + " " + i[1]);
        }
    }