adminlogin.java

浪子学习的留言本 主要功能就是记录留言

package guestbook;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import sun.misc.BASE64Decoder;

public class adminlogin extends HttpServlet
{
  public void doGet(HttpServletRequest request,
    HttpServletResponse response) throws ServletException,
    IOException
  {
    Init init=new Init(getServletContext().getRealPath("/"));
    response.setContentType("text/html; charset=GB2312");

    //get authorization header
    String authorization = request.getHeader("Authorization");

    if (authorization == null)
    {
      challenge(response); //no authorization so challenge
    }
    else
    {
      //determine if client is using basic authentication
      if (!authorization.toLowerCase().startsWith("basic"))
      {
        challenge(response); //not basic so challenge
      }

      //取经过base64编码后的帐号和密码，从字符串第六位开始取
      String namePass = authorization.substring(6).trim();

      //instantiate Base64 decoder
      BASE64Decoder decode = new BASE64Decoder();

      //decode username and password
      namePass = new String(decode.decodeBuffer(namePass));

      int colon = namePass.indexOf(":");

      //get username and password from decoded authorization text
      String username = namePass.substring(0, colon);
      String password = namePass.substring(colon+1);

      //validate username and password (case sensitive)
      if (!username.equals(init.getSuperName()) ||!password.equals(init.getSuperPassword()))
      {
        challenge(response); //invalid credentials so challenge
      }
      else
      {
        //验证通过后就写如cookie
        Cookie myCookie=new Cookie("ADMIN",init.getSuperName());
        response.addCookie(myCookie);
        response.sendRedirect("index.jsp");
      }
    }
  }


//向浏览器响应401头
  private void challenge(HttpServletResponse response)
  {
    response.setStatus(response.SC_UNAUTHORIZED);
    response.setHeader("WWW-Authenticate", "Basic realm=\"Login\"");
  }
}