字符串中找出连续最长的数字串

import java.util.Scanner;import java.util.regex.Matcher;import java.util.regex.Pattern;public class Main{     static final String reg = "[0-9]+";     static Pattern pattern = Pattern.compile(reg);    public static void main(String[] args){        Scanner in = new Scanner(System.in);        String maxStr = maxLengthNum(in.next());        System.out.println(maxStr);    }    public static String maxLengthNum(String str){        Matcher matcher = pattern.matcher(str);        String maxStr = "";        int maxLen = 0;        String tempStr = "";        while(matcher.find()){            tempStr = matcher.group();            if(tempStr.length() > maxLen){                maxLen = tempStr.length();                maxStr = tempStr;            }        }        return maxStr;    }}