equals方法if语句验证用户密码 - JAVA

import java.util.Scanner;

public class CheckLogin {
public static void main(String[]args)
{
Scanner scanner = new Scanner(System.in);
System.out.println("请输入登陆的用户名：");
String usernameString = scanner.nextLine();
System.out.println("请输入登陆的密码：");
String passwordString = scanner.nextLine();
if (!usernameString.equals("nihao")) {

System.out.println("用户名错误");

}
else if (!passwordString.equals("123")) {
System.out.println("密码错误");

}
else {
System.out.println("通过验证");
}
}

}