正则表达式

匹配规则：

 

 

 

正则表达式的常见案例：

 

package com.zjm.Regex;

import java.util.Scanner;

public class Demo01 {
    public static void main(String[] args) {
        //需求：校验手机号码 邮箱 电话号码
        //checkPhone();
        //checkTel();
        //checkEmail();
        checkMoney();
    }

    //11位手机号
    public static void checkPhone(){
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("请输入你的手机号：");
            String phone = sc.next();
            if(phone.matches("1[3-9]\\d{9}")){
                System.out.println("输入正确，注册成功！");
                break;
            }else{
                System.out.println("输入有误，请重新输入！");
            }
        }
    }

    //带区号电话
    public static void checkTel(){
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("请输入你的电话号码：");
            String tel = sc.next();
            //027-3572457  0273572457
            if(tel.matches("0\\d{2,6}-?\\d{5,20}")){
                System.out.println("输入正确，注册成功！");
                break;
            }else{
                System.out.println("输入有误，请重新输入！");
            }
        }
    }

    //邮箱号
    public static void checkEmail(){
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("请输入你的邮箱号码：");
            String email = sc.next();
            //326885787@qq.com    231375dashd@163.com   32743dag23@pic.com.cn
            if(email.matches("\\w{1,30}@[a-zA-Z0-9]{2,20}(\\.[a-zA-Z0-9]{2,20}){1,2}")){
                System.out.println("输入正确，注册成功！");
                break;
            }else{
                System.out.println("输入有误，请重新输入！");
            }
        }
    }
    //金额
    public static void checkMoney(){
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("请输入你的金额：");
            String money = sc.next();
            if(money.matches("\\d+(\\.\\d{1,2})?")){
                System.out.println("输入正确!");
                break;
            }else{
                System.out.println("输入有误，请重新输入！");
            }
        }
    }
}

 

 

正则表达式的在方法中的应用：

 

 

package com.zjm.Regex;

public class Demo02 {
    public static void main(String[] args) {
        String names = "小舞dasj132jdhsjfs唐三dsja43kfsks飞猪djsk_h1小明";
        String[] arrs = names.split("\\w+");
        for (String s : arrs) {
            System.out.println(s);
        }

        String names2 = names.replaceAll("\\w+"," ");
        System.out.println(names2);
    }
}

 正则表达式爬取信息：

 

package com.zjm.Regex;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Demo03 {
    public static void main(String[] args) {
        String rs = "来黑马程序学习Java,电话020-43422424，或者联系邮箱" +
                "itcast@itcast.cn,电话18762832633，0203232323" +
                "邮箱bozai@itcast.cn, 400-100-3233 ，4001003232";

        //1.定义爬取规则，字符串形式
        String regex = "\\w{1,30}@[a-zA-Z0-9]{2,20}(\\.[a-zA-Z0-9]{2,20}){1,2}" +
                "|0\\d{2,6}-?\\d{5,20}|400-?\\d{3,9}-?\\d{3,9}";

        //2.把爬取规则编译成匹配对象
        Pattern pattern = Pattern.compile(regex);

        //3.得到一个内容匹配对象
        Matcher matcher = pattern.matcher(rs);

        //4.开始爬取
        while (matcher.find()){
            String rs1 = matcher.group();
            System.out.println(rs1);
        }
    }

}