import java.sql.*; import java.util.*; public class sqltest {   public static void main(String[] args) throws ClassNotFoundException, SQLException{         Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");   String url="jdbc:microsoft:Ssqlserver://localhost:1433;DataBaseName=liu";      String username="liu";   String password=" ";   Connection conn = DriverManager.getConnection(url,username,password);      Statement stt=conn.createStatement();   ResultSet rs=stt.executeQuery("select* from uptable");   String username1=rs.getString(username);   String password1=rs.getString(password);   Scanner rd=new Scanner(System.in);   System.out.println("请输入登陆账号：");   String username2=rd.next();   System.out.println("请输入登录密码：");   String password2=rd.next();   if(username2.equals(username1)&&password2.equals(password1)){   System.out.println("登陆成功");   }   else   System.out.println("你输入的账号或者密码不正确！");         } }

呜呜

这样很乱啊!

运行时提示是什么?

好乱。。。。。。。。。。。。        

编译通过，运行不知咋回事！