import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String str = scanner.next(); String emailMatcher = "[a-zA-Z0-9]+@[a-zA-Z0-9]+\\.[a-zA-Z0-9]+"; //write your code here...... if (str.matches(emailMatcher)) { System.out.println("邮箱格式合法"); } else { System.out.println("邮箱格式不合法"); } } }