输入输出

import java.util.Scanner;

public class Demo {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("请输入用户名：");
String username = sc.nextLine();
System.out.println("请输入密码：");
String password = sc.nextLine();
if ("mr".equals(username) || "123456".equals(password)) {
System.out.println("登录成功");
} else {
System.out.println("用户名或密码错误");
}

    sc.close();
}

}