class Check{ public boolean validate(String name,String password){  if(name.equals("huangjiashuai")&&password.equals("hjs")){   return true;  }else{   return false;  } }}class Operate{ private String info[]; public Operate(String info[]){  this.info=info; } public String login(){  Check check= new Check();  this.isExit();  String name = this.info[0];  String password = this.info[1];  String str = null;  if(check.validate(name, password)){   str = "欢迎"+name+"光临！";  }else{   str = "错误的用户名和密码！";  }  return str; } public void isExit(){  if(this.info.length!=2){   System.out.println("输入的参数不正确，系统退出！");   System.out.println("格式：java LoginDemo02 用户名 密码");   System.exit(1);  } }}public class LoginDemo02{ public static void main(String args[]){  Operate oper = new Operate(args);  System.out.println(oper.login()); }}