jsp登陆模块

  <%          //判断是否登陆

if((String)session.getValue("user_name")!=null) {

         String name=(String)session.getAttribute("user_name");

         sql="select * from member where user_name='"+name+"'";

         rs=stmt.executeQuery(sql);

         if(rs.next()){

 %>

         <tr align="justify" valign="top">

             <td width="120" height="20">用户名:</td>

             <td width="51" height="20"><%=rs.getString("user_name")%></td>

         </tr>

         <tr>

             <td height="25">地址:</td>

             <td height="25"></td>

         </tr>

         <tr>

              <td height="25" colspan="2">

             <div align="center"><a href="index.jsp?loginout=true">退出登录</a>

                  </div>

              </td>

         </tr>

 <%

    }

 

 }else

 //没有登陆

 {

 %>             

          <tr>

                <td> <div align="center">客户：</div></td>

                <td> <div align="center">

                <input name="user_name" type="text" class=input id="user_name" style="FONT-SIZE: 12px; WIDTH: 110px" size="10" maxlength="18">

                </div></td>

          </tr>

           <tr>

                 <td> <div align="center">密码：</div></td>

                 <td> <div align="center">

                 <input style="FONT-SIZE: 12px; WIDTH: 110px" type="password" name="user_pass" size="10" class=input maxlength="18">

                 </div></td>

          </tr>

          <tr>

                    <td colspan="2" nowrap><div align="center">

                 <input type="submit" name="Submit2" value="登录">                                                              

                                  　

                 <input type="button" name="Submit" value="用户注册" onClick="javascript:window.location.href='reguser.jsp'">

                  </div></td>

          </tr>

       

                    

<%

}//判断登陆结束

 

String loginout=request.getParameter("loginout");//退出登陆

         if(loginout!=null)

         {

                   if(loginout.compareTo("true")==0)

                   {

                            session.removeAttribute("user_name");

                            response.sendRedirect("index.jsp");

                   }

         }

%>