loginservlet.java

通过jsp,servlet,javaBean,三成架构实现的好友通讯录系统

package com.servelet;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import com.entity.UserBean;
import com.Dao.userDao;

public class LoginServlet extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GB2312";

    //Initialize global variables
    public void init() throws ServletException {
    }

    //Process the HTTP Post request
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        try {
            response.setContentType(CONTENT_TYPE);
            HttpSession session = request.getSession();
            PrintWriter out = response.getWriter();
            response.setCharacterEncoding("GB2312");

            String rondom1 = request.getParameter("rondom");
            //获得图片中的验证码
            String rondom2 = (String) session.getAttribute("random");
            if (!rondom2.equals(rondom1)) {
                 response.sendRedirect("index.jsp");
            } else {
                String name=request.getParameter("userName");
                String password=request.getParameter("password");

                userDao userdao=new userDao();
                UserBean user=userdao.findUser(name,password);
                if(user==null || user.getUserName()==null)
                {
                    request.getRequestDispatcher("index.jsp").forward(request,response);
                }
                else
                {//如果登陆成功 保存用户信息到Session 中  已被以后需要用到用户信息
                    session.setAttribute("user",user);
                    request.getRequestDispatcher("displayservlet").forward(request,response);
         }
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
    //Clean up resources
    public void destroy() {
    }
}