1. 前言
1.1 为什么要学习正则表达式
1.1.1 极速体验正则表达式威力
/**
* 体验正则表达式的威力，给我们文本处理带来哪些便利
*/
public class Regexp_ {
public static void main(String[] args) {
//假定，编写了爬虫，从百度页面得到如下文本
// String content = "1995年，互联网的蓬勃发展给了Oak机会。业界为了使死板、单调的" +
// "静态网页能够“灵活”起来，急需一种软件技术来开发一种程序，这种程序可以通" +
// "过网络传播并且能够跨平台运行。于是，世界各大IT企业为此纷纷投入了大量的" +
// "人力、物力和财力。这个时候，Sun公司想起了那个被搁置起来很久的Oak，并且" +
// "重新审视了那个用软件编写的试验平台，由于它是按照嵌入式系统硬件平台体系结" +
// "构进行编写的，所以非常小，特别适用于网络上的传输系统，而Oak也是一种精简的" +
// "语言，程序非常小，适合在网络上传输。Sun公司首先推出了可以嵌入网页并且可以" +
// "随同网页在网络上传输的Applet（Applet是一种将小程序嵌入到网页中进行执行的技术），" +
// "并将Oak更名为Java（在申请注册商标时，发现Oak已经被人使用了，再想了一系列" +
// "名字之后，最终，使用了提议者在喝一杯Java咖啡时无意提到的Java词" +
// "语）。5月23日，Sun公司在Sun world会议上正式发" +
// "布Java和HotJava浏览器。IBM、Apple、DEC、Adobe、HP、Oracle、Netscape和微软" +
// "等各大公司都纷纷停止了自己的相关开发项目，竞相购买了Java使用许可证，并为自己的产" +
// "品开发了相应的Java平台";
// String content = "<div class=\"cr-content new-pmd\">\n" +
// " \n" +
// "<div class=\"FYB_RD\">\n" +
// " <div class=\"cr-title c-gap-bottom-xsmall\" title=\"百度热榜\">\n" +
// " <span class=\"c-color-t\">百度热榜</span>\n" +
// " <div class=\"opr-toplist1-update opr-toplist1-link\" data-click=\"{fm:'beha'}\" style=\"position:relative;top:-1px;\">\n" +
// " <a class=\"OP_LOG_BTN toplist-refresh-btn c-font-normal c-color-gray2\" href=\"javascript:void(0);\" style=\"text-decoration:none;\">\n" +
// " <i class=\"c-icon opr-toplist1-hot-refresh-icon\"></i><span>换一换</span>\n" +
// " </a>\n" +
// " </div>\n" +
// " </div>\n" +
// " <table class=\"c-table opr-toplist1-table\">\n" +
// " <tbody >\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-top toplist1-hot-0 c-index-single-hot1 \" style=\"opacity:1;\">\n" +
// " 1\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"印度累计确诊病例已超2000万例\" href=\"/s?wd=%E5%8D%B0%E5%BA%A6%E7%B4%AF%E8%AE%A1%E7%A1%AE%E8%AF%8A%E7%97%85%E4%BE%8B%E5%B7%B2%E8%B6%852000%E4%B8%87%E4%BE%8B&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=abf2fwdknQ1VTZk3EzyT0N5%2FpcQzkjPt5GRZchjVdppW7k8B8oI6R5IL3T0myEMmjxXM&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_1\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 印度累计确诊病例已超2000万例\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">473万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-top toplist1-hot-1 c-index-single-hot2 \" style=\"opacity:1;\">\n" +
// " 2\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"五一酒店外卖订单涨2倍\" href=\"/s?wd=%E4%BA%94%E4%B8%80%E9%85%92%E5%BA%97%E5%A4%96%E5%8D%96%E8%AE%A2%E5%8D%95%E6%B6%A82%E5%80%8D&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=32d1XGZJfky0Fpb6VgCcSv3Dnyp6JpbQ9TN%2BOvfioGkBC4T9m1Qp%2FFuwHnF9APvBaVr6&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_2\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 五一酒店外卖订单涨2倍\n" +
// " </a>\n" +
// " <span class=\"c-text c-text-hot opr-toplist1-label\">热</span>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">441万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-top toplist1-hot-2 c-index-single-hot3 \" style=\"opacity:1;\">\n" +
// " 3\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"印度籍无症状感染者密接曾参加婚宴\" href=\"/s?wd=%E5%8D%B0%E5%BA%A6%E7%B1%8D%E6%97%A0%E7%97%87%E7%8A%B6%E6%84%9F%E6%9F%93%E8%80%85%E5%AF%86%E6%8E%A5%E6%9B%BE%E5%8F%82%E5%8A%A0%E5%A9%9A%E5%AE%B4&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=79d48aiFJI7IvPi2BpW6Iy6VbHfAcV1uBdvZO8pb0chgf%2FK1Ic9Krgz3m43Aeg38VSM2&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_3\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 印度籍无症状感染者密接曾参加婚宴\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">425万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 4\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"这次是真正的国潮\" href=\"/s?wd=%E7%99%BE%E5%BA%A6%E5%9B%BD%E6%BD%AE%E5%AD%A3&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=fecdvAqz0R7aEIPJxobhfnLd1otn461fSeGWr8pqx3cGZkJ%2F98S1hWn6sBK8%2Fujuf6Nx&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_4\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 这次是真正的国潮\n" +
// " </a>\n" +
// " <span class=\"c-text c-text-rec opr-toplist1-label\">荐</span>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">396万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 5\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"墨西哥轨交设施坍塌监控曝光\" href=\"/s?wd=%E5%A2%A8%E8%A5%BF%E5%93%A5%E8%BD%A8%E4%BA%A4%E8%AE%BE%E6%96%BD%E5%9D%8D%E5%A1%8C%E7%9B%91%E6%8E%A7%E6%9B%9D%E5%85%89&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=83bfOvia%2BOoGl9qutbaK5%2BfI3hDeC3FAdCyV%2F4cPmjZE6QeMZoMNyLCMOFpF7gkN8Tp4&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_5\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 墨西哥轨交设施坍塌监控曝光\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">382万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 6\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"印度供应全球六成新冠疫苗\" href=\"/s?wd=%E5%8D%B0%E5%BA%A6%E4%BE%9B%E5%BA%94%E5%85%A8%E7%90%83%E5%85%AD%E6%88%90%E6%96%B0%E5%86%A0%E7%96%AB%E8%8B%97&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=3b01YqbH3sPvmvx8Ck5Gq9NosRAi7F%2BITPb5d%2FbYkMlFMu2Fr%2FmPyqbcGiCPL1NUup5f&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_6\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 印度供应全球六成新冠疫苗\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">369万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 7\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"少女因病辍学4年写下500篇文章\" href=\"/s?wd=%E5%B0%91%E5%A5%B3%E5%9B%A0%E7%97%85%E8%BE%8D%E5%AD%A64%E5%B9%B4%E5%86%99%E4%B8%8B500%E7%AF%87%E6%96%87%E7%AB%A0&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=fac0t6ySTlYJYViu68pbr90yeoYsdLzmJ3yoFS63MgmLVAe1EOH2pJPITFtCLWasq1Y5&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_7\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 少女因病辍学4年写下500篇文章\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">356万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 8\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"售价2200元的“神药”成本仅50元\" href=\"/s?wd=%E5%94%AE%E4%BB%B72200%E5%85%83%E7%9A%84%E2%80%9C%E7%A5%9E%E8%8D%AF%E2%80%9D%E6%88%90%E6%9C%AC%E4%BB%8550%E5%85%83&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=cdddugWl4sZtX04FYWIZbl9Cyyc7pZWX9sh0KvfPqgzqNBivbI2vdiJMrq72Bq4gXqHk&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_8\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 售价2200元的“神药”成本仅50元\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">343万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 9\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"央视五四晚会节目单出炉\" href=\"/s?wd=%E5%A4%AE%E8%A7%86%E4%BA%94%E5%9B%9B%E6%99%9A%E4%BC%9A%E8%8A%82%E7%9B%AE%E5%8D%95%E5%87%BA%E7%82%89&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=2f67NoNuMuoV3aLTdna3uIzyEJGhxDThWFkMH0z1ZV0obHc0WxGWL2QaN0roTrKMjCYC&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_9\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 央视五四晚会节目单出炉\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">331万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 10\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"91岁巴菲特选出继任者\" href=\"/s?wd=91%E5%B2%81%E5%B7%B4%E8%8F%B2%E7%89%B9%E9%80%89%E5%87%BA%E7%BB%A7%E4%BB%BB%E8%80%85&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=7d429xUUJZLFLSMjZR6habx13%2BdASsly6zcvmnhdiq5T%2BY8PaleKBxypUgU7onDWZfXf&rsf=dd45f07d69719294a2ea6117b312f1d7_1_10_10\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 91岁巴菲特选出继任者\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">320万</td>\n" +
// " </tr>\n" +
// " </tbody>\n" +
// " <tbody style=\"display:none\">\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 11\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"8旬退休教授为贫困生捐70万\" href=\"/s?wd=8%E6%97%AC%E9%80%80%E4%BC%91%E6%95%99%E6%8E%88%E4%B8%BA%E8%B4%AB%E5%9B%B0%E7%94%9F%E6%8D%9070%E4%B8%87&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=f57amyz02ho2MnkxxIB0zWHTw9CDEypEMVB2PBlBNcy37%2FJ9T1VwBcokXXZOxr2jvv9G&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_11\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 8旬退休教授为贫困生捐70万\n" +
// " </a>\n" +
// " <span class=\"c-text c-text-new opr-toplist1-label\">新</span>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">309万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 12\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"女子为给偶像删帖被骗8000元\" href=\"/s?wd=%E5%A5%B3%E5%AD%90%E4%B8%BA%E7%BB%99%E5%81%B6%E5%83%8F%E5%88%A0%E5%B8%96%E8%A2%AB%E9%AA%978000%E5%85%83&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=86c1ICmWkGtTaB7UqvG0ysxoljgkHlWe%2BWHEX0V8s8zxcKIzmN2gkudtAYvsBpNvYDOj&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_12\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 女子为给偶像删帖被骗8000元\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">298万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 13\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"比尔·盖茨夫妇离婚 女儿发声\" href=\"/s?wd=%E6%AF%94%E5%B0%94%C2%B7%E7%9B%96%E8%8C%A8%E5%A4%AB%E5%A6%87%E7%A6%BB%E5%A9%9A+%E5%A5%B3%E5%84%BF%E5%8F%91%E5%A3%B0&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=896490eILJu%2FQTiRLPviDBzceznJ4WDcrcARkLwmE0XCIpTu3PrKFwO6F4UrH7PInzJf&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_13\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 比尔·盖茨夫妇离婚 女儿发声\n" +
// " </a>\n" +
// " <span class=\"c-text c-text-hot opr-toplist1-label\">热</span>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">287万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 14\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"学生18种语言演唱追梦赤子心\" href=\"/s?wd=%E5%AD%A6%E7%94%9F18%E7%A7%8D%E8%AF%AD%E8%A8%80%E6%BC%94%E5%94%B1%E8%BF%BD%E6%A2%A6%E8%B5%A4%E5%AD%90%E5%BF%83&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=3f72LcjlesGwBj0Clhi%2Bb%2F2VReCDWnVIAhD2gY8ek2xyxp7CdywyGDo4umYaRhP3221H&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_14\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 学生18种语言演唱追梦赤子心\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">277万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 15\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"少林寺500多年古碑遭熊孩子刻画\" href=\"/s?wd=%E5%B0%91%E6%9E%97%E5%AF%BA500%E5%A4%9A%E5%B9%B4%E5%8F%A4%E7%A2%91%E9%81%AD%E7%86%8A%E5%AD%A9%E5%AD%90%E5%88%BB%E7%94%BB&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=c269Co2zIeZtuzyqqsvebsim1bobIW%2B%2BjfTjg71RfZnwmws3ig67InXI3vNu4fzOeXWU&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_15\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 少林寺500多年古碑遭熊孩子刻画\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">268万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 16\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"比尔·盖茨发文希望保护隐私\" href=\"/s?wd=%E6%AF%94%E5%B0%94%C2%B7%E7%9B%96%E8%8C%A8%E5%8F%91%E6%96%87%E5%B8%8C%E6%9C%9B%E4%BF%9D%E6%8A%A4%E9%9A%90%E7%A7%81&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=10dcmr4dz3wKqdfJkFOOE0IXaxZmGtm1I6jFQji1C3vuy4HISFpAUfeeI7sh133z7hSq&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_16\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 比尔·盖茨发文希望保护隐私\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">258万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 17\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"韩国青年排队抢购奢侈品\" href=\"/s?wd=%E9%9F%A9%E5%9B%BD%E9%9D%92%E5%B9%B4%E6%8E%92%E9%98%9F%E6%8A%A2%E8%B4%AD%E5%A5%A2%E4%BE%88%E5%93%81&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=d978WNnZlLwmlF%2BvU8n7Zc%2FcwTRpOrntJEL93BpoZZKZqw3IqNftMckCKsE4lxm1cKDq&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_17\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 韩国青年排队抢购奢侈品\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">249万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 18\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"李开复谈盖茨夫妇离婚\" href=\"/s?wd=%E6%9D%8E%E5%BC%80%E5%A4%8D%E8%B0%88%E7%9B%96%E8%8C%A8%E5%A4%AB%E5%A6%87%E7%A6%BB%E5%A9%9A&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=8b26lOeJYdFsbzrlKHrtA%2BqP%2B72mxliaQQeuWBA4WevfUhj2awgHfQiliYz%2FKHekOWLq&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_18\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 李开复谈盖茨夫妇离婚\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">240万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal opr-toplist1-one-font\" style=\"opacity:1;\">\n" +
// " 19\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"秦昊看伊能静演出\" href=\"/s?wd=%E7%A7%A6%E6%98%8A%E7%9C%8B%E4%BC%8A%E8%83%BD%E9%9D%99%E6%BC%94%E5%87%BA&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=1b57U64YpaHqGvduMc0cFIo7gLTIrQ4lM21aDbL4sxYl0oynCKAEFut9HCWJNIzytl%2Fa&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_19\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 秦昊看伊能静演出\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">232万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 20\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"医生景区救人获终身免门票\" href=\"/s?wd=%E5%8C%BB%E7%94%9F%E6%99%AF%E5%8C%BA%E6%95%91%E4%BA%BA%E8%8E%B7%E7%BB%88%E8%BA%AB%E5%85%8D%E9%97%A8%E7%A5%A8&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=a286ytHBPeiBaO6ftRxaSzW%2FHXDoDA1d%2BMHbSGjzMIU9mhXPBiNYKGK0S142wLZGMl1B&rsf=dd45f07d69719294a2ea6117b312f1d7_11_20_20\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 医生景区救人获终身免门票\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">224万</td>\n" +
// " </tr>\n" +
// " </tbody>\n" +
// " <tbody style=\"display:none\">\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 21\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"31省区市新增确诊17例均为境外输入\" href=\"/s?wd=31%E7%9C%81%E5%8C%BA%E5%B8%82%E6%96%B0%E5%A2%9E%E7%A1%AE%E8%AF%8A17%E4%BE%8B%E5%9D%87%E4%B8%BA%E5%A2%83%E5%A4%96%E8%BE%93%E5%85%A5&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=df27aIqxHhQIcAkMctyNR3AZ7%2Bc%2BAFGjTdYqB9bg2gSDU95OAwTih0Zlw%2B45tFVdw%2Fb%2B&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_21\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 31省区市新增确诊17例均为境外输入\n" +
// " </a>\n" +
// " <span class=\"c-text c-text-hot opr-toplist1-label\">热</span>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">216万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 22\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"95后00后成红色旅游出游主力\" href=\"/s?wd=95%E5%90%8E00%E5%90%8E%E6%88%90%E7%BA%A2%E8%89%B2%E6%97%85%E6%B8%B8%E5%87%BA%E6%B8%B8%E4%B8%BB%E5%8A%9B&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=9684bWy5j1gUATPXvoTZQmKIrX6gg%2Fyj%2F5x1JWcvXjz%2FpWmHSKBymZqnL6Bb3Ypms7Aq&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_22\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 95后00后成红色旅游出游主力\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">208万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 23\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"男子爬玻璃栈桥防护栏被逐出景区\" href=\"/s?wd=%E7%94%B7%E5%AD%90%E7%88%AC%E7%8E%BB%E7%92%83%E6%A0%88%E6%A1%A5%E9%98%B2%E6%8A%A4%E6%A0%8F%E8%A2%AB%E9%80%90%E5%87%BA%E6%99%AF%E5%8C%BA&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=d38b0oqpz16NpoH6i3B45MNJZgknKbf4Lyjmkh7DPDc%2FD1v8u%2BK9diDAcH%2FzyUUwJufK&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_23\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 男子爬玻璃栈桥防护栏被逐出景区\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">201万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 24\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"美国近三分之一人完成疫苗两针接种\" href=\"/s?wd=%E7%BE%8E%E5%9B%BD%E8%BF%91%E4%B8%89%E5%88%86%E4%B9%8B%E4%B8%80%E4%BA%BA%E5%AE%8C%E6%88%90%E7%96%AB%E8%8B%97%E4%B8%A4%E9%92%88%E6%8E%A5%E7%A7%8D&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=8543F244DfP53qkV4K1yeWjVehoD8tduIx%2B0VOZb%2BVVSNxNFMdIpULyxiQ%2BlsUdv51hM&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_24\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 美国近三分之一人完成疫苗两针接种\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">194万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 25\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"萧敬腾在广州参加活动下大雨\" href=\"/s?wd=%E8%90%A7%E6%95%AC%E8%85%BE%E5%9C%A8%E5%B9%BF%E5%B7%9E%E5%8F%82%E5%8A%A0%E6%B4%BB%E5%8A%A8%E4%B8%8B%E5%A4%A7%E9%9B%A8&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=04613AvycY3GvCKQQB6P6T0DRTH5ObmzFA5b0Bz4CrxddgOpuldpmQfSbhVStcmZoHjI&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_25\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 萧敬腾在广州参加活动下大雨\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">187万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 26\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"女子夜店内抱娃蹦迪\" href=\"/s?wd=%E5%A5%B3%E5%AD%90%E5%A4%9C%E5%BA%97%E5%86%85%E6%8A%B1%E5%A8%83%E8%B9%A6%E8%BF%AA&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=466c7vsJ6Lu%2BEK8aRHLwwL%2Bf8wHeXjubIYyiewtTQq%2BqQcV9CTRxakAwZDoh25aVmsQA&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_26\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 女子夜店内抱娃蹦迪\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">181万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 27\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"姚明说CBA要给年轻球员机会\" href=\"/s?wd=%E5%A7%9A%E6%98%8E%E8%AF%B4CBA%E8%A6%81%E7%BB%99%E5%B9%B4%E8%BD%BB%E7%90%83%E5%91%98%E6%9C%BA%E4%BC%9A&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=5dcdVKFZQj03MQo3bSpvWCa2nmuarhCkyaGwUTpme7K7Tp4Fvbr9Xe%2FWFNJOFSHLFv3w&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_27\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 姚明说CBA要给年轻球员机会\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">174万</td>\n" +
// " </tr>\n" +
// " <tr class=\"toplist1-tr\">\n" +
// " \n" +
// " <td class=\"toplist1-td opr-toplist1-link\">\n" +
// " <span class=\"toplist1-hot c-index-single toplist1-hot-normal \" style=\"opacity:1;\">\n" +
// " 28\n" +
// " </span>\n" +
// " <a target=\"_blank\" title=\"黄秋生在台隔离期间被诈骗\" href=\"/s?wd=%E9%BB%84%E7%A7%8B%E7%94%9F%E5%9C%A8%E5%8F%B0%E9%9A%94%E7%A6%BB%E6%9C%9F%E9%97%B4%E8%A2%AB%E8%AF%88%E9%AA%97&rsv_idx=2&tn=baiduhome_pg&usm=3&ie=utf-8&rsv_cq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_dl=0_right_fyb_pchot_20811_01&rsv_pq=959254a60034f017&oq=%E5%91%A8%E6%98%9F%E9%A9%B0&rsv_t=9f9app%2FvUpebIOcqeTXr8MAHsM5IZp4JJ8oCLPiLfIu6DeChK1Z3jv6Ttr3i3hUUNhcW&rsf=dd45f07d69719294a2ea6117b312f1d7_21_30_28\" class=\"c-font-medium c-color-t opr-toplist1-subtitle\">\n" +
// " 黄秋生在台隔离期间被诈骗\n" +
// " </a>\n" +
// " </td>\n" +
// " <td class=\"toplist1-right-num toplist1-td c-color-gray\" style=\"line-height:20px;position:relative;top:2px;\">168万</td>\n" +
// " </tr>\n" +
// " </tbody> </table>\n" +
// " </div>";
String content = "私有地址（Private address）属于非注册地址，专门为组织机构内部使用。\n" +
"以下列出留用的内部私有地址\n" +
"A类 10.0.0.0--10.255.255.255\n" +
"B类 172.16.0.0--172.31.255.255\n" +
"C类 192.168.0.0--192.168.255.255";
//提取文章中所有的英文单词
//提取文章中所有的数字
//提取文章中所有的英文单词和数字
//提取百度热榜 标题
//(1). 传统方法. 使用遍历方式，代码量大，效率不高
//(2). 正则表达式技术
//1. 先创建一个Pattern对象 ， 模式对象, 可以理解成就是一个正则表达式对象
//Pattern pattern = Pattern.compile("[a-zA-Z]+");
//Pattern pattern = Pattern.compile("[0-9]+");
//Pattern pattern = Pattern.compile("([0-9]+)|([a-zA-Z]+)");
//Pattern pattern = Pattern.compile("<a target=\"_blank\" title=\"(\\S*)\"");
Pattern pattern = Pattern.compile("\\d+\\.\\d+\\.\\d+\\.\\d+");
//2. 创建一个匹配器对象
//理解： 就是 matcher 匹配器按照 pattern(模式/样式), 到 content 文本中去匹配
//找到就返回true, 否则就返回false
int no = 0;
Matcher matcher = pattern.matcher(content);
//3. 可以开始循环匹配
while (matcher.find()) {
//匹配内容，文本，放到 m.group(0)
System.out.println("找到: " + (++no) + " " +matcher.group(0));
}
}
}
1.2 再提出几个问题?
1.3 解决之道-正则表达式
2. 正则表达式基本介绍
全称：regular expression
2.1 介绍
3. 正则表达式底层实现( 重要 )
3.1 实例分析
为让大家对正则表达式底层实现有一个直观的映象，给大家举个实例，给你一段字符串(文本),请找出所有四个数字连在一起的子串， 比如:
应该找到 1998 1999 3443 9889
分析底层实现：
RegTheory.java
/**
* 分析java的正则表达式的底层实现(重要.)
*/
public class RegTheory {
public static void main(String[] args) {
String content = "1998年12月8日，第二代Java平台的企业版J2EE发布。1999年6月，Sun公司发布了" +
"第二代Java平台（简称为Java2）的3个版本：J2ME（Java2 Micro Edition，Java2平台的微型" +
"版），应用于移动、无线及有限资源的环境；J2SE（Java 2 Standard Edition，Java 2平台的" +
"标准版），应用于桌面环境；J2EE（Java 2Enterprise Edition，Java 2平台的企业版），应" +
"用3443于基于Java的应用服务器。Java 2平台的发布，是Java发展过程中最重要的一个" +
"里程碑，标志着Java的应用开始普及9889 ";
//目标：匹配所有四个数字
//说明
//1. \\d 表示一个任意的数字
String regStr = "(\\d\\d)(\\d\\d)";
//2. 创建模式对象[即正则表达式对象]
Pattern pattern = Pattern.compile(regStr);
//3. 创建匹配器
//说明：创建匹配器matcher， 按照 正则表达式的规则 去匹配 content字符串
Matcher matcher = pattern.matcher(content);
//4.开始匹配
/**
*
* matcher.find() 完成的任务 （考虑分组）
* 什么是分组，比如 (\d\d)(\d\d) ,正则表达式中有() 表示分组,第1个()表示第1组,第2个()表示第2组...
* 1. 根据指定的规则 ,定位满足规则的子字符串(比如(19)(98))
* 2. 找到后，将 子字符串的开始的索引记录到 matcher对象的属性 int[] groups;
* 2.1 groups[0] = 0 , 把该子字符串的结束的索引+1的值记录到 groups[1] = 4
* 2.2 记录1组()匹配到的字符串 groups[2] = 0 groups[3] = 2
* 2.3 记录2组()匹配到的字符串 groups[4] = 2 groups[5] = 4
* 2.4.如果有更多的分组.....
* 3. 同时记录oldLast 的值为 子字符串的结束的 索引+1的值即35, 即下次执行find时，就从35开始匹配
*
* matcher.group(0) 分析
*
* 源码:
* public String group(int group) {
* if (first < 0)
* throw new IllegalStateException("No match found");
* if (group < 0 || group > groupCount())
* throw new IndexOutOfBoundsException("No group " + group);
* if ((groups[group*2] == -1) || (groups[group*2+1] == -1))
* return null;
* return getSubSequence(groups[group * 2], groups[group * 2 + 1]).toString();
* }
* 1. 根据 groups[0]=31 和 groups[1]=35 的记录的位置，从content开始截取子字符串返回
* 就是 [31,35) 包含 31 但是不包含索引为 35的位置
*
* 如果再次指向 find方法.仍然安上面分析来执行
*/
while (matcher.find()) {
//小结
//1. 如果正则表达式有() 即分组
//2. 取出匹配的字符串规则如下
//3. group(0) 表示匹配到的子字符串
//4. group(1) 表示匹配到的子字符串的第一组字串
//5. group(2) 表示匹配到的子字符串的第2组字串
//6. ... 但是分组的数不能越界.
System.out.println("找到: " + matcher.group(0));
System.out.println("第1组()匹配到的值=" + matcher.group(1));
System.out.println("第2组()匹配到的值=" + matcher.group(2));
}
}
}
4. 正则表达式语法
4.1 基本介绍
4.2 元字符(Metacharacter)-转义号 \\
/**
* 演示转义字符的使用
*/
public class RegExp02 {
public static void main(String[] args) {
String content = "abc$(a.bc(123( )";
//匹配( => \\(
//匹配. => \\.
//匹配/ => \\/
//匹配\ => \\\\
String regStr = "\\.";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到 " + matcher.group(0));
}
}
}
4.3 元字符-字符匹配符
/**
* 演示字符匹配符 的使用
*/
public class RegExp03 {
public static void main(String[] args) {
String content = "a11c8abc _ABCy @";
//String regStr = "[a-z]";//匹配 a-z之间任意一个字符
//String regStr = "[A-Z]";//匹配 A-Z之间任意一个字符
//String regStr = "abc";//匹配 abc 字符串[默认区分大小写]
//String regStr = "(?i)abc";//匹配 abc 字符串[不区分大小写]
//String regStr = "[0-9]";//匹配 0-9 之间任意一个字符
//String regStr = "[^a-z]";//匹配 不在 a-z之间任意一个字符
//String regStr = "[^0-9]";//匹配 不在 0-9之间任意一个字符
//String regStr = "[abcd]";//匹配 在 abcd中任意一个字符
//String regStr = "\\D";//匹配 不在 0-9的任意一个字符
//String regStr = "\\w";//匹配 大小写英文字母, 数字，下划线
//String regStr = "\\W";//匹配 等价于 [^a-zA-Z0-9_]
//\\s 匹配任何空白字符(空格,制表符等)
//String regStr = "\\s";
//\\S 匹配任何非空白字符 ,和\\s刚好相反
//String regStr = "\\S";
//. 匹配出 \n 之外的所有字符,如果要匹配.本身则需要使用 \\.
String regStr = ".";
//说明
//1. 当创建Pattern对象时，指定 Pattern.CASE_INSENSITIVE, 表示匹配是不区分字母大小写.
Pattern pattern = Pattern.compile(regStr/*, Pattern.CASE_INSENSITIVE*/);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到 " + matcher.group(0));
}
}
}
4.4 元字符-选择匹配符
/**
* 选择匹配符
*/
public class RegExp04 {
public static void main(String[] args) {
String content = "hanshunping 韩 寒冷";
String regStr = "han|韩|寒";
Pattern pattern = Pattern.compile(regStr/*, Pattern.CASE_INSENSITIVE*/);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到 " + matcher.group(0));
}
}
}
4.5 元字符-限定符
用于指定其前面的字符和组合项连续出现多少次
/**
* @author 韩顺平
* @version 1.0
* 演示限定符的使用
*/
public class RegExp05 {
public static void main(String[] args) {
String content = "a211111aaaaaahello";
//a{3},1{4},\\d{2}
//String regStr = "a{3}";// 表示匹配 aaa
//String regStr = "1{4}";// 表示匹配 1111
//String regStr = "\\d{2}";// 表示匹配 两位的任意数字字符
//a{3,4},1{4,5},\\d{2,5}
//细节：java匹配默认贪婪匹配，即尽可能匹配多的
//String regStr = "a{3,4}"; //表示匹配 aaa 或者 aaaa
//String regStr = "1{4,5}"; //表示匹配 1111 或者 11111
//String regStr = "\\d{2,5}"; //匹配2位数或者3,4,5位数
//1+
//String regStr = "1+"; //匹配一个1或者多个1
//String regStr = "\\d+"; //匹配一个数字或者多个数字
//1*
//String regStr = "1*"; //匹配0个1或者多个1
//演示?的使用, 遵守贪婪匹配
String regStr = "a1?"; //匹配 a 或者 a1
Pattern pattern = Pattern.compile(regStr/*, Pattern.CASE_INSENSITIVE*/);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到 " + matcher.group(0));
}
}
}
4.6 元字符-定位符
定位符, 规定要匹配的字符串出现的位置，比如在字符串的开始还是在结束的位置，这个也是相当有用的，必须掌握！
/**
* 演示定位符的使用
*/
public class RegExp06 {
public static void main(String[] args) {
String content = "hanshunping sphan nnhan";
//String content = "123-abc";
//以至少1个数字开头，后接任意个小写字母的字符串
//String regStr = "^[0-9]+[a-z]*";
//以至少1个数字开头, 必须以至少一个小写字母结束
//String regStr = "^[0-9]+\\-[a-z]+$";
//表示匹配边界的han[这里的边界是指：被匹配的字符串最后,
// 也可以是空格的子字符串的后面]
//String regStr = "han\\b";
//和\\b的含义刚刚相反
String regStr = "han\\B";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到=" + matcher.group(0));
}
}
}
4.7 分组
4.7.1 捕获分组
/**
* 分组:
*/
public class RegExp07 {
public static void main(String[] args) {
String content = "hanshunping s7789 nn1189han";
//下面就是非命名分组
//说明
// 1. matcher.group(0) 得到匹配到的字符串
// 2. matcher.group(1) 得到匹配到的字符串的第1个分组内容
// 3. matcher.group(2) 得到匹配到的字符串的第2个分组内容
//String regStr = "(\\d\\d)(\\d\\d)";//匹配4个数字的字符串
//命名分组： 即可以给分组取名
String regStr = "(?<g1>\\d\\d)(?<g2>\\d\\d)";//匹配4个数字的字符串
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到=" + matcher.group(0));
System.out.println("第1个分组内容=" + matcher.group(1));
System.out.println("第1个分组内容[通过组名]=" + matcher.group("g1"));
System.out.println("第2个分组内容=" + matcher.group(2));
System.out.println("第2个分组内容[通过组名]=" + matcher.group("g2"));
}
}
}
4.7.2 非捕获分组
/**
* 演示非捕获分组, 语法比较奇怪
*/
public class RegExp08 {
public static void main(String[] args) {
String content = "hello达内教育 jack达内老师 达内同学hello达内学生";
// 找到 达内教育 、达内老师、达内同学 子字符串
//String regStr = "达内教育|达内老师|达内同学";
//上面的写法可以等价非捕获分组, 注意：不能 matcher.group(1)
//String regStr = "达内(?:教育|老师|同学)";
//找到 达内 这个关键字,但是要求只是查找达内教育和 达内老师 中包含有的达内
//下面也是非捕获分组，不能使用 matcher.group(1)
//String regStr = "达内(?=教育|老师)";
//找到 达内 这个关键字,但是要求只是查找 不是 (达内教育 和 达内老师) 中包含有的达内
//下面也是非捕获分组，不能使用 matcher.group(1)
String regStr = "达内(?!教育|老师)";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到: " + matcher.group(0));
}
}
}
4.8 非贪婪匹配
/**
* 非贪婪匹配
*/
public class RegExp09 {
public static void main(String[] args) {
String content = "hello111111 ok";
//String regStr = "\\d+"; //默认是贪婪匹配
// String regStr = "\\d+?"; //非贪婪匹配
String regStr = "\\d+?"; //非贪婪匹配
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到: " + matcher.group(0));
}
}
}
4.9 了解更多请查看相关文档
5. 应用实例
5.1 对字符串进行如下验证
/**
* 正则表达式的应用实例
*/
public class RegExp10 {
public static void main(String[] args) {
String content = "13588889999";
// 汉字
//String regStr = "^[\u0391-\uffe5]+$";
// 邮政编码
// 要求：1.是1-9开头的一个六位数. 比如：123890
// 2.
// 3.
//String regStr = "^[1-9]\\d{5}$";
// QQ号码
// 要求: 是1-9开头的一个(5位数-10位数) 比如: 12389 , 1345687 , 187698765
//String regStr = "^[1-9]\\d{4,9}$";
// 手机号码
// 要求: 必须以13,14,15,18 开头的11位数 , 比如 13588889999
String regStr = "^1[3|4|5|8]\\d{9}$";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
if(matcher.find()) {
System.out.println("满足格式");
} else {
System.out.println("不满足格式");
}
}
}
总结：
以什么位数结尾的可以添加$定位符修饰
/**
* 演示正则表达式的使用
*/
public class RegExp11 {
public static void main(String[] args) {
//String content = "https://www.bilibili.com/video/BV1fh411y7R8?from=search&seid=1831060912083761326";
String content = "http://edu.3dsmax.tech/yg/bilibili/my6652/pc/qg/05-51/index.html#201211-1?track_id=jMc0jn-hm-yHrNfVad37YdhOUh41XYmjlss9zocM26gspY5ArwWuxb4wYWpmh2Q7GzR7doU0wLkViEhUlO1qNtukyAgake2jG1bTd23lR57XzV83E9bAXWkStcAh4j9Dz7a87ThGlqgdCZ2zpQy33a0SVNMfmJLSNnDzJ71TU68Rc-3PKE7VA3kYzjk4RrKU";
/**
* 思路
* 1. 先确定 url 的开始部分 https:// | http://
* 2.然后通过 ([\w-]+\.)+[\w-]+ 匹配 www.bilibili.com
* 3. /video/BV1fh411y7R8?from=sear 匹配(\/[\w-?=&/%.#]*)?
*/
String regStr = "^((http|https)://)?([\\w-]+\\.)+[\\w-]+(\\/[\\w-?=&/%.#]*)?$";//注意：[. ? *]表示匹配就是.本身
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
if(matcher.find()) {
System.out.println("满足格式");
} else {
System.out.println("不满足格式");
}
//这里如果使用Pattern的matches 整体匹配 比较简洁
System.out.println(Pattern.matches(regStr, content));
}
}
总结：
做一些复杂的正则题目时，可以使用拆分的思想，将表达式拆成各个部分进行处理
6. 正则表达式三个常用类
/**
* 演示Pattern方法，用于整体匹配, 在验证输入的字符串是否满足条件使用
*/
public class PatternMethod {
public static void main(String[] args) {
String content = "hello abc hello, 韩顺平教育";
//String regStr = "hello";
String regStr = "hello.*";
boolean matches = Pattern.matches(regStr, content);
System.out.println("整体匹配= " + matches);
}
}
/**
* Matcher 类的常用方法
*/
public class MatcherMethod {
public static void main(String[] args) {
String content = "hello edu jack hspedutom hello smith hello hspedu hspedu";
String regStr = "hello";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("=================");
System.out.println(matcher.start());
System.out.println(matcher.end());
System.out.println("找到: " + content.substring(matcher.start(), matcher.end()));
}
//整体匹配方法，常用于，去校验某个字符串是否满足某个规则
System.out.println("整体匹配=" + matcher.matches());
//完成如果content 有 hspedu 替换成 韩顺平教育
regStr = "hspedu";
pattern = Pattern.compile(regStr);
matcher = pattern.matcher(content);
//注意：返回的字符串才是替换后的字符串 原来的 content 不变化
String newContent = matcher.replaceAll("韩顺平教育");
System.out.println("newContent=" + newContent);
System.out.println("content=" + content);
}
}
7. 分组、捕获、反向引用
7.1 提出需求
7.2 介绍
7.3 看几个小案例
/**
* 反向引用
*/
public class RegExp12 {
public static void main(String[] args) {
String content = "h1234el9876lo33333 j12324-333999111a1551ck14 tom11 jack22 yyy12345 xxx";
//要匹配两个连续的相同数字 : (\\d)\\1
//String regStr = "(\\d)\\1";
//要匹配五个连续的相同数字： (\\d)\\1{4}
//String regStr = "(\\d)\\1{4}";
//要匹配个位与千位相同，十位与百位相同的数 5225 , 1551 (\\d)(\\d)\\2\\1
//String regStr = "(\\d)(\\d)\\2\\1";
/**
* 请在字符串中检索商品编号,形式如:12321-333999111 这样的号码,
* 要求满足前面是一个五位数,然后一个-号,然后是一个九位数,连续的每三位要相同
*/
String regStr = "\\d{5}-(\\d)\\1{2}(\\d)\\2{2}(\\d)\\3{2}";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()) {
System.out.println("找到 " + matcher.group(0));
}
}
}
7.4 经典的结巴程序
把 类似 : “我…我要…学学学学…编程 java!”;
通过正则表达式 修改成 “我要学编程 java”
public class RegExp13 {
public static void main(String[] args) {
String content = "我....我要....学学学学....编程java!";
//1. 去掉所有的.
Pattern pattern = Pattern.compile("\\.");
Matcher matcher = pattern.matcher(content);
content = matcher.replaceAll("");
// System.out.println("content=" + content);
//2. 去掉重复的字 我我要学学学学编程java!
// 思路
//(1) 使用 (.)\\1+
//(2) 使用 反向引用$1 来替换匹配到的内容
// 注意：因为正则表达式变化，所以需要重置 matcher
// pattern = Pattern.compile("(.)\\1+");//分组的捕获内容记录到$1
// matcher = pattern.matcher(content);
// while (matcher.find()) {
// System.out.println("找到=" + matcher.group(0));
// }
//
// //使用 反向引用$1 来替换匹配到的内容
// content = matcher.replaceAll("$1");
// System.out.println("content=" + content);
//3. 使用一条语句 去掉重复的字 我我要学学学学编程java!
content = Pattern.compile("(.)\\1+").matcher(content).replaceAll("$1");
System.out.println("content=" + content);
}
}
8. String 类中使用正则表达式
8.1 替换功能
String 类 public String replaceAll(String regex,String replacement)
8.2 判断功能
String 类 public boolean matches(String regex){} //使用 Pattern 和 Matcher 类
8.3 分割功能
String 类 public String[] split(String regex)
8.4 应用实例
public class StringReg {
public static void main(String[] args) {
String content = "2000年5月，JDK1.3、JDK1.4和J2SE1.3相继发布，几周后其" +
"获得了Apple公司Mac OS X的工业标准的支持。2001年9月24日，J2EE1.3发" +
"布。" +
"2002年2月26日，J2SE1.4发布。自此Java的计算能力有了大幅提升";
//使用正则表达式方式，将 JDK1.3 和 JDK1.4 替换成JDK
content = content.replaceAll("JDK1\\.3|JDK1\\.4", "JDK");
System.out.println(content);
//要求 验证一个 手机号， 要求必须是以138 139 开头的
content = "13888889999";
if (content.matches("1(38|39)\\d{8}")) {
System.out.println("验证成功");
} else {
System.out.println("验证失败");
}
//要求按照 # 或者 - 或者 ~ 或者 数字 来分割
System.out.println("===================");
content = "hello#abc-jack12smith~北京";
String[] split = content.split("#|-|~|\\d+");
for (String s : split) {
System.out.println(s);
}
}
}
9. 本章作业
Homework01.java
public class Homework01 {
public static void main(String[] args) {
//规定电子邮件规则为
//只能有一个@
//@前面是用户名,可以是a-z A-Z 0-9 _-字符
//@后面是域名,并且域名只能是英文字母， 比如 sohu.com 或者 tsinghua.org.cn
// 写出对应的正则表达式, 验证输入的字符串是否为满足规则
String content = "hsp@tsinghua.org.cn kkk";
String regStr = "^[\\w-]+@([a-zA-Z]+\\.)+[a-zA-Z]+$";
//老师说明
//1. String 的 matches 是整体匹配
//2. 看看这个matches 底层
/**
* String 的 matches
* public boolean matches(String regex) {
* return Pattern.matches(regex, this);
* }
*
* Pattern
* public static boolean matches(String regex, CharSequence input) {
* Pattern p = Pattern.compile(regex);
* Matcher m = p.matcher(input);
* return m.matches();
* }
*
* Mather类 match
* Attempts to match the entire region against the pattern
* public boolean matches() {
* return match(from, ENDANCHOR);
* }
*/
if (content.matches(regStr)) {
System.out.println("匹配成功");
} else {
System.out.println("匹配失败");
}
}
}
Homework02.java
public class Homework02 {
public static void main(String[] args) {
//要求验证是不是整数或者小数
//提示： 这个题要考虑正数和负数
//比如： 123 -345 34.89 -87.9 -0.01 0.45 等
/**
* 老师的思路
* 1. 先写出简单的正则表达式
* 2. 在逐步的完善[根据各种情况来完善]
*/
String content = "-0.89"; //
String regStr = "^[-+]?([1-9]\\d*|0)(\\.\\d+)?$";
if(content.matches(regStr)) {
System.out.println("匹配成功 是整数或者小数");
} else {
System.out.println("匹配失败");
}
}
}
Homework03.java
public class Homework03 {
public static void main(String[] args) {
String content = "http://www.sohu.com:8080/abc/xxx/yyy/inde@#$%x.htm";
//因为正则表达式是根据要求来编写的，所以，如果需求需要的话，可以改进.
String regStr = "^([a-zA-Z]+)://([a-zA-Z.]+):(\\d+)[\\w-/]*/([\\w.@#$%]+)$";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
if(matcher.matches()) {//整体匹配, 如果匹配成功，可以通过group(x), 获取对应分组的内容
System.out.println("整体匹配=" + matcher.group(0));
System.out.println("协议: " + matcher.group(1));
System.out.println("域名: " + matcher.group(2));
System.out.println("端口: " + matcher.group(3));
System.out.println("文件: " + matcher.group(4));
} else {
System.out.println("没有匹配成功");
}
}
}
