这是JSP页面里的一个表单：
<div id="main_content02" style="display:">
<table >
<form name="product" id="product" action="InsertProductServlet" method="post" enctype="multipart/form-data">
<tr>
<td id="tit">物品类别:</td>
<td><select name="product_class" id="text">
<option value="0">数码产品</option>
<option value="1">家庭电器</option>
<option value="2">鞋包配饰</option>
<option value="3">汽车摩托</option>
<option value="4">护肤彩妆</option>
<option value="5">珠宝手表</option>
</select></td>
</tr>
<tr>
<td id="tit">物品名称：</td>
<td><input name="productName" type="text" id="text"/></td>
</tr>
<tr>
<td id="tit">底价：</td>
<td><input name="productPrice" type="text" id="text"/></td>
</tr>
<tr>
<td id="tit">价值：</td>
<td><input name="productCost" type="text" id="text"/></td>
</tr>
<tr>
<td id="tit">物品图片：</td>
<td ><input name="upfile" type="file" id="text" value="上传" style="width:228px;"/>
<input type="button" style="background-color:#900; width: 50px; height: 20px;
color: #FFF; border: none; line-height: 20px" value="上传" onclick="userIsExists()"/>
<input type="hidden" name="path" value="${sessionScope.image}"/>
</td>
</tr>
<tr>
<td id="tit" align="left">截止日期：</td>
<td><input name="productCloseTime" type="text" id="text"/></td>
</tr>
<tr>
<td id="tit" valign="top">物品描述：</td>
<td><textarea name="productDescribe" cols="" rows="" id="Describe"></textarea></td>
</tr>
<tr>
<td colspan="2" align="center">
<input type="hidden" name="user" value="${sessionScope.client.clientId}"/>
<input type="submit" id="client_btn" value="提交"/>
</td>
</tr>
</form>
</table>
用servlet来获取值：
import auction.dao.ProductDao;
import auction.dao.impl.ProductDaoImpl;
import auction.entity.Product;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
@WebServlet(name = "InsertProductServlet", urlPatterns = {"/InsertProductServlet", "/html/InsertProductServlet"})
public class InsertProductServlet extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
//获取用户输入的数据
PrintWriter out = response.getWriter();
String productName=getParameter(request,"productName");
String classId=getParameter(request,"product_class");
String clientId=getParameter(request,"user");
String productPrice=getParameter(request,"productPrice");
String productDescribe=getParameter(request,"productDescribe");
String productCost=getParameter(request,"productCost");
String productCloseTime=getParameter(request,"productCloseTime");
String productImage=getParameter(request,"path");