package com.jaxc.scan;

import java.util.regex.Matcher;

import java.util.regex.Pattern;



public class ReadTxtUtils{
    public static void main(String[] args) {
        String s = "我爱          五星红旗";

        System.out.println(s.replaceAll(" ", ",").trim());
        //处理后输出：我爱,,,,,,,,,,五星红旗

        String regEx = "[' ']+"; // 一个或多个空格

        Pattern p = Pattern.compile(regEx);

        Matcher m = p.matcher(s);

        System.out.println(m.replaceAll(",").trim());
        //处理后输出:我爱,五星红旗

    }

}

处理字符串单个或多个空格替换