loginservlet.java

本系统是一个具有交互功能的C2C类型的电子商务网站（客户与客户之间进行商品交易的平台）

package myservlet.s;
import mybean.b.*;
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class LogInServlet extends HttpServlet{
  public void init(ServletConfig config)throws ServletException{
    super.init(config);
    try{
        Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
    }catch(Exception e){}
  }
  public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
   Connection con;
   Statement sql;
   String backnews="";
   HttpSession session=request.getSession(true);
   LogInBean loginbean=(LogInBean)session.getAttribute("loginbean");
   if(loginbean==null){
      loginbean=new LogInBean();
      session.setAttribute("loginbean",loginbean);
   }
   String sloginname=request.getParameter("loginname").trim();
   String sloginpassword=request.getParameter("loginpassword").trim();
   boolean boo1=loginbean.getIssuccess();
   String str=loginbean.getLoginname();
   try{
         if(boo1&&sloginname.equals(str)){
           backnews="该帐户已经登陆!";
           loginbean.setBacknews(backnews);
          }
         else{
            con=DriverManager.getConnection("jdbc:sqlserver://127.0.0.1:1433;DatabaseName=shopping","shop","123");
            sql=con.createStatement();
            String querystr="select * from users where UserName='"+sloginname+"' and UserPassWord='"+sloginpassword+"'";
            ResultSet rs=sql.executeQuery(querystr);
            boolean boo2=rs.next();
            if(boo2){
               backnews=":登陆成功!";
               loginbean.setBacknews(backnews);
               loginbean.setLoginname(sloginname);       
               loginbean.setLoginpassword(sloginpassword);
               loginbean.setIssuccess(true);     
            }
            else{
               backnews="帐户不存在或密码错误!";
               loginbean.setBacknews(backnews);
               loginbean.setLoginname(sloginname);       
               loginbean.setLoginpassword(sloginpassword);
               loginbean.setIssuccess(false);
            }
            con.close();
       }       
   }catch(SQLException e){backnews=""+e;loginbean.setBacknews(backnews);}
   RequestDispatcher dispatcher=request.getRequestDispatcher("index1.jsp");
   dispatcher.forward(request,response);
  }
  public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
   doPost(request,response);
  }
}