在字符串中找出连续最长的数字串

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            String input = sc.nextLine();
            new Main().getLongestNumString(input);
        }
    }

    public void getLongestNumString(String str) {
        char[] arr = str.toCharArray();
        StringBuilder tmp = new StringBuilder();
        String ret = "";
        List<String> list = new ArrayList<>();
        boolean isConsecutive = false;
        for (char ch : arr) {
            if (Character.isDigit(ch)) {
                if (!isConsecutive) {
                    tmp = new StringBuilder();
                }
                tmp.append(ch);
                isConsecutive = true;
                if (ret.length() < tmp.toString().length()) {
                    ret = tmp.toString();
                    list.clear();
                    list.add(ret);
                } else if (ret.length() == tmp.toString().length()) {
                    list.add(tmp.toString());
                }
            } else {
                isConsecutive = false;
            }
        }

        for (String string : list) {
            System.out.print(string);
        }
        System.out.print(","+ret.length());
        System.out.println();
    }

}