1 package 验证登录信息是否合法; 2  3 import java.util.Scanner; 4  5 public class Login_Message_If_Legal { 6     public static void main(String[] args) { 7         Scanner input=new Scanner(System.in); 8         boolean loop=true; 9         while(loop){10             System.out.println("Please enter your username:");11             String Name=input.nextLine();12             if(Name.equals("sa")){13                 14             }else{15                 System.err.println("UserNaem is error,please again!");16                 continue;17             }18             System.out.println("please your password:");19             String password=input.nextLine();20             if(password.equals("1314")){21                 22             }else{23                 System.err.println("password is error,please again!");24                 continue;25             }    26             loop=false;27             System.out.println("login successful!");28         }        29     }30 }