写了一个客户关系管理系统,进行查询的时候值没取到是什么原因
Servlet代码程序代码:
package cn.itcast.servlet; import import java.util.List; /** * 条件查询的servlet */ import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cn.itcast.service.CustomerService; import cn.itcast.vo.Customer; public class ListConditionCustomerServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /** * 1、接收数据 * 2、调用Service * 3、显示到JSP * */ //接收数据 request.setCharacterEncoding("UTF-8"); String paramName=request.getParameter("paramName"); String paramValue=request.getParameter("paramValue"); //调用Service CustomerService cs=new CustomerService(); List<Customer> list=cs.findByCondition(paramName,paramValue); //显示到JSP request.setAttribute("List", list); request.getRequestDispatcher("/myjsp/listCustomer.jsp").forward(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
JSP的
程序代码:
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java. prefix="c" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www. http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <h1>显示所有客户</h1> <form action="${pageContext.request.contextPath }/ListConditionCustomerServlet" method="post"> <table border="1" width="100%"> <tr> <td> <select name="paramName"> <!-- <% request.getParameter("paramName"); %> --> <option value="name"<c:if test="${paramName=='name' }">selected</c:if>>按姓名 </option> <option value="type"<c:if test="${paramName=='type' }">selected</c:if>>按类型 </option> </select> <input type="text" name="paramValue"/> <input type="submit" value="查询"> </td> </tr> </table> </form> <table border="1" width="100%"> <tr> <td>序号</td> <td>客户姓名</td> <td>客户性别</td> <td>客户生日</td> <td>客户电话</td> <td>客户邮箱</td> <td>客户爱好</td> <td>客户类型</td> <td>客户描述</td> <td>操作</td> </tr> <c:forEach var="customer" items="${list }" varStatus="status"> <tr> <td>${status.count }</td> <td>${customer.name }</td> <td>${customer.gender }</td> <td>${customer.birthday }</td> <td>${customer.cellphone }</td> <td>${customer.email }</td> <td>${customer.hobby }</td> <td>${customer.type }</td> <td>${customer.description }</td> <td><a href="${ pageContext.request.contextPath }/EditCustomerServlet?id=${ customer.id }">编辑</a>|<a href="${ pageContext.request.contextPath }/DeleteCustomerServlet?id=${ customer.id }">删除</a></td> </tr> </c:forEach> </table> </body> </html>