request.getParameter无法获取前台的值

---------------------login.html----------------------------

 <script type="text/javascript">

$(function(){inEvent();});

function inEvent(){$("#regSubmit").click(formSubmit);

$("#divdialog").css("display","none");}


function formSubmit() {$.post("LoginServlet",$("#form2").serialize(),function (data) {if (data == 1) {
$("#divdialog").css("display", "");

$("#divdialog").html("登陆成功");
$("#divdialog").dialog({title:"登陆成功提示",modal:true,buttons:
{"确定并跳转":function(){$(this).dialog("close");
location.href="index.html";
},"关闭":
function(){$(this).dialog("close");}}});}else{alert("data值为0"); $("#divdialog").html("有错误发生,可能是用户名或密码错误!");$("#divdialog").dialog({title:"登陆失败提示",modal:true,buttons:{"关闭":function(){$(this).dialog("close");}}});}});}

</script>  
</head>

<body>
<div class="main">
<div class="login">
<h1>学生管理系统</h1>
<div class="inset">

<form  method="post" id="form2" name="form2">
     <div>
        <h2>登录</h2>
            <span><label>用户名</label></span>
            <span><input name="tbusername" type="text" id="tbusername" class="textbox" ></span>
            </div>
            <div>
        <span><label>密码</label></span>
        <span><input name="tbpassword" type="password" id="tbpassword" class="password"></span>
    </div>
  <div class="sign">
   <input name="regSubmit" type="button" value="登录" id="regSubmit" class="submit" />
  <a href='reg.html'><input type="button" value="注册" class="submit" /></a>
</div> 
<div id="divdialog" title="我是JQuery,欢迎您的到来">
<p>JQuery模态对话框:确定删除用户信息?</p>
</div>                     
</form>

-----------------------servlet------------------------

 import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");  
        String tbusername=  request.getParameter("tbusername");     
        String tbpassword=  request.getParameter("tbpassword");     

        System.out.println(tbusername); //返回null
        System.out.println(tbusername);//返回null

        try {

            Class.forName("com.mysql.jdbc.Driver");
            Connection cn=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/student","root","123456");
            PreparedStatement ps=cn.prepareStatement("SELECT * FROM userreg WHERE username=? AND pwd=?");
            ps.setString(1,tbusername);
            ps.setString(2,tbpassword);
            ResultSet rs=ps.executeQuery();

            if(rs.next()){
//              System.out.println("密码对");
                response.getWriter().print("1");
            }else{
//              System.out.println("密码错");
                response.getWriter().print("0");
            }
        } catch (Exception e) {

            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }

}


小兄弟,你的这个排版,看着辣眼啊

你把 $("#form2").serialize(),在前台打印,看是否真有值
看下,你前台的属性名是否和后台的paremeter名一致

 $("#form2").serialize()传的是这个吗?打出来看看

function formSubmit() {
$.post("LoginServlet",
$("#form2").serialize(),
function (data) {
if (data == 1) {
/* alert($("#form2").serialize()); 无效 */
$("#divdialog").css("display", "");
$("#divdialog").html("登陆成功");
$("#divdialog").dialog({

                title:"登陆成功提示",
                modal:true,
                buttons:{
                    "确定并跳转":function(){
                        $(this).dialog("close");
                        location.href="index.html";
                        },
                        "关闭":function(){
                            $(this).dialog("close");
                            }
                    }
                });
            }
            else{
            /* alert($("#form2").serialize());  能成功获取  */
                $("#divdialog").html("有错误发生,可能是用户名或密码错误!");
                $("#divdialog").dialog({
                    title:"登陆失败提示",
                    modal:true,
                    buttons:{
                        "关闭":function(){
                            $(this).dialog("close");
                            }
                        }
                    });
                }
        }

    );

}