Matcher和Pattern的应用(要import引入)

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

public class Main {
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        String str = scanner.next();
        String regexEmail="[a-zA-Z0-9]+@[a-zA-Z0-9]+\\.[a-zA-Z0-9]+";
        Matcher matcher = Pattern.compile(regexEmail).matcher(str);
        System.out.println(matcher.find() ? "邮箱格式合法" : "邮箱格式不合法");
    }
}