正则表达式学习
- 1.初始正则表达式
- 1.1正则表达式练习1
- 1.2正则表达式练习2
- 1.3正则表达式练习3
- 2.正则表达式源码分析
- 2.1 源码分析-matcher.find()
- 2.2源码分析- matcher.group(0)
- 2.3 整体代码
- 2.4源码分析-分组()
- 3.正则表达式语法
- 3.0元字符(Metacharacter)-转义号 `\\`
- 3.1限定符
- 3.2选择匹配符
- 3.3分组组合
- 3.4字符匹配符
- 3.5定位符
- 3.6反向引用
- 4.正则表达式的应用实例
- 4.1验证是不是汉字
- 4.2 验证邮政编码
- 4.3验证QQ号格式
- 4.4手机号格式验证
- 4.5URL
- 4.6经典的结巴程序
- 5.1Pattern类 -matches方法
- 6.String类中使用正则表达式
- 6.1替换字符
- 6.2判断功能
- 6.3分割功能
- 6.4验证电子邮件是否合法
- 6.5验证是不是整数或者小数
- 6.6对url进行解析
1.初始正则表达式
正则表达式是对字符串执行模式匹配的技术
1.1正则表达式练习1
- 提取content中所有的英文单词
- 提取content中所有的数字
- 提取content中所有的英文单词和数字
package Regexp_;
import org.omg.CosNaming.NamingContextExtPackage.StringNameHelper;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg1 {
public static void main(String[] args) {
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。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。";
Pattern pattern = Pattern.compile("([0-9]+|[a-zA-Z]+)");
Matcher matcher = pattern.matcher(content);
while (matcher.find()){
System.out.println("找到:"+ matcher.group(0));
}
}
}
1.2正则表达式练习2
提取百度热搜的标题
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg2 {
public static void main(String[] args) {
String context=" <div class=\"ntes-quicknav-list\">\n" +
" <div class=\"ntes-quicknav-content\">\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-1\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://news.163.com\">新闻</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://news.163.com/domestic\">国内</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://news.163.com/world\">国际</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://view.163.com\">评论</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://war.163.com\">军事</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://news.163.com/special/wangsansanhome/\">王三三</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-2\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://sports.163.com\">体育</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/nba\">NBA</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/cba\">CBA</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/allsports\">综合</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/zc\">中超</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/world\">国际足球</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/yc\">英超</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/xj\">西甲</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sports.163.com/yj\">意甲</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-3\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://ent.163.com\">娱乐</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://ent.163.com/star\">明星</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://ent.163.com/photo\">图片</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://ent.163.com/movie\">电影</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://ent.163.com/tv\">电视</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://ent.163.com/music\">音乐</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://ent.163.com/special/gsbjb/\">稿事编辑部</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://ent.163.com/special/focus_ent/\">娱乐FOCUS</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-4\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://money.163.com\">财经</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://money.163.com/stock\">股票</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"http://quotes.money.163.com/stock\">行情</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://money.163.com/ipo\">新股</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://money.163.com/finance\">金融</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://money.163.com/fund\">基金</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://biz.163.com\">商业</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://money.163.com/licai\">理财</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-5\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://auto.163.com\">汽车</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://auto.163.com/buy\">购车</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://auto.163.com/depreciate\">行情</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"http://product.auto.163.com\">车型库</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://auto.163.com/elec\">新能源</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://auto.163.com/news\">行业</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-6\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://tech.163.com\">科技</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://tech.163.com/telecom/\">通信</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://tech.163.com/it\">IT</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://tech.163.com/internet\">互联网</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://tech.163.com/special/chzt\">特别策划</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://tech.163.com/smart/\">网易智能</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-7\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://fashion.163.com\">时尚</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://baby.163.com\">亲子</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://fashion.163.com/art\">艺术</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-8\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://mobile.163.com\">手机</a>\n" +
" <span>/</span>\n" +
" <a href=\"https://digi.163.com/\">数码</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://tech.163.com/special/ydhlw\">移动互联网</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://mobile.163.com/special/jqkj_list/\">惊奇科技</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://mobile.163.com/special/cpshi_list/\">易评机</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-9\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://house.163.com\">房产</a>\n" +
" <span>/</span>\n" +
" <a href=\"https://home.163.com\">家居</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://bj.house.163.com\">北京房产</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://sh.house.163.com\">上海房产</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://gz.house.163.com\">广州房产</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://house.163.com/city\">全部分站</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://xf.house.163.com\">楼盘库</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://home.163.com/jiaju/\">家具</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://home.163.com/weiyu/\">卫浴</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-10\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://travel.163.com\">旅游</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://travel.163.com/outdoor\">户外</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://travel.163.com/food\">美食</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://travel.163.com/special/travellist/#f=endnav\">专题</a>\n" +
" </li>\n" +
" </ul>\n" +
" <ul class=\"ntes-quicknav-column ntes-quicknav-column-11\">\n" +
" <li>\n" +
" <h3>\n" +
" <a href=\"https://edu.163.com\">教育</a>\n" +
" </h3>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://edu.163.com/yimin\">移民</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://edu.163.com/liuxue\">留学</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://edu.163.com/en\">外语</a>\n" +
" </li>\n" +
" <li>\n" +
" <a href=\"https://edu.163.com/gaokao\">高考</a>\n" +
" </li>\n" +
" </ul>";
Pattern pattern = Pattern.compile("<a href=\"(\\S*)\">(\\S*)</a>");
Matcher matcher = pattern.matcher(context);
while (matcher.find()){
System.out.println("找到:"+ matcher.group(0));
}
}
}
1.3正则表达式练习3
- 给你一个字符串(或文章),请你找出所有四个数字连在一起的子串?
- 给你一个字符串(或文章),请你找出所有四个数字连在一起的子串,并且这四个数字要满足:第一位与第四位相同,第二位与第三位相同,比如1221, 5775
2.正则表达式源码分析
2.1 源码分析-matcher.find()
matcher.find() 完成的任务
- 根据指定的规则 ,定位满足规则的子字符串(比如1998),
- 找到后,将子字符串 开始的索引 记录到 matcher 对象的属性
int[] groups
groups[0] =0
,把该子字符串的结束的索引+1
的值记录到groups[1]=4
- 同时记录
oldLast
的值 为子字符串 的结束的索引+1 的值 即 4,即下次执行find 时 就从4开始匹配
2.2源码分析- matcher.group(0)
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();
}
- 根据 groups[0]=0和groups[1] =1的记录位置,从context开始截取子字符串返回就是[0,4) 包含0 但是不包含索引4 -1998
- 如果再次执行find方法,仍然按照上面分析来执行
groups[0]=31和groups[1]=35
包含31 但是不包含索引35 -1999
2.3 整体代码
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg3 {
public static void main(String[] args) {
String context="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。";
String regStr="\\d\\d\\d\\d";
Pattern pattern =Pattern.compile(regStr);
Matcher matcher = pattern.matcher(context);
while (matcher.find()){
System.out.println("找到:"+matcher.group(0));
}
}
}
2.4源码分析-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()
表示第一组,第2个()
表示第二组
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg4 {
public static void main(String[] args) {
String context="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。";
String regStr="(\\d\\d)(\\d\\d)";
Pattern pattern =Pattern.compile(regStr);
Matcher matcher = pattern.matcher(context);
while (matcher.find()){
System.out.println("找到:"+matcher.group(0));
System.out.println("第一组()匹配到的值="+matcher.group(1));
System.out.println("第二组()匹配到的值="+matcher.group(2));
}
}
}
matcher.find()
- 根据指定的规则 ,定位满足规则的子字符串(比如
(19)(98)
), - 找到后,将子字符串 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 记录第一组匹配到的字符串groups[2]= 0
, groups[3]=2 (19)
2.3 记录第一组匹配到的字符串groups[4]= 2
, groups[5]=2 (98)
2.4 如果有更多的分组,依次类推…
System.out.println("找到:"+matcher.group(0));
System.out.println("第一组()匹配到的值="+matcher.group(1));
System.out.println("第二组()匹配到的值="+matcher.group(2));
3.正则表达式语法
各种元字符的功能
3.0元字符(Metacharacter)-转义号 \\
-
\\
符号:在我们使用正则表达式去检索某些特殊字符的时候,需要用到转义符号,否则检索不到 结果,甚至会报错。
-
在java正则表达式中,两个\\
代表其他语言中的一个\
-
需要用到转义符号的字符有
. * + () $ / \ ? [] ^ { }
3.1限定符
用于指定其前面的字符和组合项连续出现多少次
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg7 {
public static void main(String[] args) {
String content="111234Aa2a1abbbccd13511";
String regStr="a1?";
Pattern pattern =Pattern.compile(regStr);
Matcher matcher =pattern.matcher(content);
while (matcher.find()){
System.out.println("找到:"+matcher.group(0));
}
}
}
3.2选择匹配符
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg6 {
public static void main(String[] args) {
String context="后羿射手 houyisheshou 社长";
String regStr="射|she|社";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(context);
while (matcher.find()){
System.out.println("找到:"+matcher.group(0));
}
}
}
3.3分组组合
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg9 {
public static void main(String[] args) {
String content ="han123 s7789 nn1189han";
String regStr ="(?<g1>\\d\\d)(?<g2>\\d\\d)";
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"));
}
}
}
非捕获分组 (?:pattern)
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg10 {
public static void main(String[] args) {
String content ="hello小明教育 jack小明老师 小明同学hello";
String regStr="小明(?:教育|老师|同学)";
Pattern pattern =Pattern.compile(regStr);
Matcher matcher =pattern.matcher(content);
while (matcher.find()){
System.out.println("找到:"+matcher.group(0));
}
}
}
非捕获分组 (?=pattern)
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg11 {
public static void main(String[] args) {
String content ="hello小明教育 jack小明老师 小明同学hello";
String regStr="小明(?=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));
}
}
}
非捕获分组(?!pattern)
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg12 {
public static void main(String[] args) {
String content ="hello小明教育 jack小明老师 小明同学hello";
String regStr="小明(?!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));
}
}
}
3.4字符匹配符
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg5 {
public static void main(String[] args) {
String content ="a11c8.a bc ABC*_";
String regStr="\\.";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()){
System.out.println("找到"+matcher.group(0));
}
}
}
3.5定位符
定位符,规定要匹配的字符出现的位置,比如在字符串的开始还是在结束的位置
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg8 {
public static void main(String[] args) {
String content ="han123resdfgsfdsdahan dphanu";
String regStr ="^[0-9]+[a-z]+$";
Pattern pattern =Pattern.compile(regStr);
Matcher matcher =pattern.matcher(content);
while (matcher.find()){
System.out.println("找到:"+matcher.group(0));
}
}
}
3.6反向引用
圆括号的内容被捕获后,可以在这个括号后被使用,从而写出一个比较实用的匹配模式,这个我们称为反向引用,这种引用既可以是在正则表达式内部,也可以是在正则表达式外部,内部反向引用\\
分组号,外部反向引用$
分组号
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg19 {
public static void main(String[] args) {
String content ="hello jack222222 tom1551 yyy xx";
String regStr="(\\d)(\\d)\\2\\1";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
while (matcher.find()){
System.out.println("找到"+matcher.group(0));
}
}
}
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg20 {
public static void main(String[] args) {
String content ="12321-333999111";
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));
}
}
}
4.正则表达式的应用实例
4.1验证是不是汉字
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg13 {
public static void main(String[] args) {
String content="小明的教育";
String regStr="^[\u0391-\uffe5]+$";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
if (matcher.find()){
System.out.println("满足格式");
}else {
System.out.println("不满足格式");
}
}
}
4.2 验证邮政编码
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg14 {
public static void main(String[] args) {
String content="523890";
String regStr="^[1-9]\\d{5}$";
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");
}
}
}
4.3验证QQ号格式
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg15 {
public static void main(String[] args) {
String content="5678950";
String regStr="^[1-9]\\d{4,9}$";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
if (matcher.find()){
System.out.println("满足格式");
}else {
System.out.println("不满足格式");
}
}
}
4.4手机号格式验证
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg16 {
public static void main(String[] args) {
String content="18668902219";
String regStr="^1[3|4|5|8]\\d{9}$";
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");
}
}
}
4.5URL
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg17 {
public static void main(String[] args) {
String content="https://www.bilibili.com/v/knowledge/?spm_id_from=333.1007.0.0";
String regStr="^((http|https)://)(([\\w-])+\\.)+[\\w-]+(\\/[\\w-?=&/%.#]*)?$";
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");
}
}
}
4.6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
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg21 {
public static void main(String[] args) {
String content ="我...我要..学学学学...编程java!";
Pattern pattern = Pattern.compile("\\.");
Matcher matcher = pattern.matcher(content);
content = matcher.replaceAll("");
System.out.println("content="+content);
content = Pattern.compile("(.)\\1+").matcher(content).replaceAll("$1");
System.out.println(content);
}
}
5.1Pattern类 -matches方法
整体匹配
package Regexp_;
import java.util.regex.Pattern;
public class Reg18 {
public static void main(String[] args) {
String content ="hello abc hello,小明";
String regStr="hello.*";
boolean matches = Pattern.matches(regStr, content);
System.out.println("整体匹配="+matches);
}
}
6.String类中使用正则表达式
6.1替换字符
package Regexp_;
public class Reg22 {
public static void main(String[] args) {
String content ="2000年5月,JDK1.3、JDK1.4和J2SE1.3相继发布,几周后其获得了Apple公司Mac OS X的工业标准的支持。" +
"2001年9月24日,J2EE1.3发布";
content = content.replaceAll("JDK1\\.3|JDK1\\.4", "JDK");
System.out.println(content);
}
}
6.2判断功能
package Regexp_;
public class Reg23 {
public static void main(String[] args) {
String content="13788899999";
boolean matches = content.matches("^1(38|39)\\d{8}");
if (matches){
System.out.println("验证成功");
}else {
System.out.println("验证失败");
}
}
}
6.3分割功能
package Regexp_;
public class Reg24 {
public static void main(String[] args) {
String content ="hell#lo-jack12sminth~本经";
String[] strings = content.split("#|-|~|\\d+");
for (String s : strings) {
System.out.println(s);
}
}
}
6.4验证电子邮件是否合法
package Regexp_;
public class Reg25 {
public static void main(String[] args) {
String content="123464@qq.com.cn";
boolean matches = content.matches("^[\\w-]+@([a-zA-Z]+\\.)+[a-zA-Z]+$");
if (matches){
System.out.println("匹配成功");
}else{
System.out.println("匹配失败");
}
}
}
6.5验证是不是整数或者小数
这个题要考虑正数和负数
比如:123 -345 34.89 -87.9 -0.01 0.45等
package Regexp_;
public class Reg26 {
public static void main(String[] args) {
String content ="0.36";
String regStr="^[-+]?([1-9]\\d*|0)(\\.\\d+)?$";
if (content.matches(regStr)){
System.out.println("匹配成功,是整数或者小数");
}else {
System.out.println("匹配失败");
}
}
}
6.6对url进行解析
package Regexp_;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Reg27 {
public static void main(String[] args) {
String content="http://www.sohu.com:8080/abc//sdsd/inde@#*/x.htm";
String regStr="^([a-zA-Z]+)://([a-zA-Z.]+):(\\d+)[\\w-/]*/([\\w.@#*/]+)$";
Pattern pattern = Pattern.compile(regStr);
Matcher matcher = pattern.matcher(content);
if (matcher.matches()){
System.out.println("整体匹配成功="+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");
}
}
}
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