字符串匹配算法对于一个开发来说肯定不会陌生，比如jdk中String类indexOf()，我们可以看看它的实现

    1.     static int indexOf(char[] source, int sourceOffset, int sourceCount,
    2.             char[] target, int targetOffset, int targetCount,
    3.             int fromIndex) {
    4.         //目标字符串是空字符串且当前索引位置大于等于源字符串长度
    5.         if (fromIndex >= sourceCount) {
    6.             return (targetCount == 0 ? sourceCount : -1);
    7.         }
    9.            //边界数据
    10.         if (fromIndex < 0) {
    11.             fromIndex = 0;
    12.         }
    13.         if (targetCount == 0) {
    14.             return fromIndex;
    15.         }
    17.         //最大匹配长度
    18.         char first = target[targetOffset];
    19.         int max = sourceOffset + (sourceCount - targetCount);
    21.         for (int i = sourceOffset + fromIndex; i <= max; i++) {
    22.             //在源字符串中查找第一个字符相同的索引
    23.             if (source[i] != first) {
    24.                 while (++i <= max && source[i] != first);
    25.             }
    27.             //匹配剩余字符串
    28.             if (i <= max) {
    29.                 int j = i + 1;
    30.                 int end = j + targetCount - 1;
    31.                 for (int k = targetOffset + 1; j < end && source[j]
    32.                         == target[k]; j++, k++);
    34.                 if (j == end) {
    35.                     /* Found whole string. */
    36.                     return i - sourceOffset;
    37.                 }
    38.             }
    39.         }
    40.         return -1;
    41.     }

    实际上，String的indexOf方法就是采用比较简单的BF(Brute Force)算法，用暴力匹配的方式实现目标字符串查找的功能

    在极端情况情况下，BF算法的时间复杂度可以达到O(n*m)

    比如源字符串是”aaaaaaa……b”，目标字符串是”aaaa…..b”（目标字符串中的a数字小于源字符串中的a的个数）

    可以看到，暴力匹配的算法虽然简单，但是性能是比较低的，实际在业务开发中我们的源字符串跟目标字符串不会太长，所以在使用过程中使用也是没有问题的。

    curl ‘https://fat-local-life-open.hellobike.com/localLife/bd/private/biz/queryAllBusinessOpportunityList‘ \
    -H ‘authority: fat-local-life-open.hellobike.com’ \
    -H ‘sec-ch-ua: “ Not A;Brand”;v=”99”, “Chromium”;v=”90”, “Google Chrome”;v=”90”‘ \
    -H ‘accept: application/json, text/plain, /‘ \
    -H ‘sec-ch-ua-mobile: ?0’ \
    -H ‘user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36’ \
    -H ‘content-type: application/json;charset=UTF-8’ \
    -H ‘origin: http://localhost:5081‘ \
    -H ‘sec-fetch-site: cross-site’ \
    -H ‘sec-fetch-mode: cors’ \
    -H ‘sec-fetch-dest: empty’ \
    -H ‘accept-language: zh-CN,zh;q=0.9’ \
    —data-raw ‘{“pageSize”:20,”pageIndex”:1,”bizToken”:”8c38d5735fb0417a9b4af703854a6d13”,”__sysTag”:”vpos-f0”}’ \
    —compressed