在jsp中用bean和servlet联合实现用户注册、登录

在jsp中用bean和servlet联合实现用户注册、登录(10)    loginConn.executeQuery("select * from tbl_user where name='" + username + "'");
   if(loginConn.rs_next())
   {
    System.out.println("Connection created!");
    if(loginConn.rs_getString("pwd").trim().equals(password))
    {
     System.out.println(loginConn.rs_getString("name"));
     return true;
    }
    else
    {
     return false;
    }
   }
   System.out.println("Test Login Success!");
   return false;
  }catch(Exception e){
   System.out.println(e.toString());
   return false;
   }
 }
 
 public static void main(String args[])
 {
  login mylogin = new login();
  System.out.println(mylogin.checklogin("shandong","shandong"));
 }
 
}

说明：
1、默认的jdk1.4中并没有servlet包，请至sun公司网页下载servlet.jar，放至jdk目录下的jre\lib\目录下，并在JCreator中设置jdk处添加servlet.jar包 

2、本Servlet用于检验用户名和密码，若正确则将用户名写入Cookie，完成后将当前页重定向到index.jsp页

五、编写检测用户是否已经登陆的bean：checkLogin.java

//checkLogin.java

//import required classes
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

//class checkLogin
public class checkLogin
{
 public String username = "";
 
 public boolean check(HttpServletRequest req,HttpServletResponse res)
 throws IOException,ServletException
 {
  String cookieName = "username";
  Cookie[] myCookies = req.getCookies();
  this.username = this.getCookieValue(myCookies,cookieName,"not found");
  PrintWriter out = res.getWriter();
  if(this.username != null)
  {  
   //out.println("早上好，" + this.username + "！");