新增Customer
添加的流程
Add New Customer 超链接连接到 newcustomer.jsp
新建 newcustomer.jsp:
在 CustomerServlet 的 addCustomer 方法中:参见注释
上图一共有 2 个请求
加载页面的请求:发出请求到页面加载完成,request 结束
点击提交按钮,到 Serlvet,发出了一个 request,Serlvet 转发到 newcustomer.jsp 直到页面加载完成,整个过程一个 request
doPost(request, response) ---> request.getRequestDispatcher(path).forward(request, response);
private void addCustomer(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 1.获取表单参数:name address phone
String name = request.getParameter("name");
String address = request.getParameter("address");
String phone = request.getParameter("phone");
// 2.检验 name 是否被占用
// 2.1调用CustomerDAO的getCountWithName(String name) 获取 name 在数据库中是否存在
long count = customerDAO.getCountWithName(name);
// 2.2若返回值大于0,则响应 newcustomer.jsp 页面, 通过转发的方式响应newcustomer.jsp
if (count > 0) {
// 2.2.1要求页面显示一个错误消息: 用户名 name已经被占用,请重新选择,
// 在request中放入一个属性message :用户名 name 已经被占用,请重新选择!
// 在页面通过request.getAttribute("message")的方式显示
request.setAttribute("message", "用户名 " + name + "已经被占用,请重新选择");
// 2.2.2 newcustomer.jsp 的表单可以回显
// 通过value="<%=request.getParameter("name") == null ? "" :
// request.getParameter("name") %>"进行回显
// 2.2.3结束方法:return
request.getRequestDispatcher("/newcustomer.jsp").forward(request, response);
return;
}
// 3.若验证通过,把表单参数封装为一个Customer 对象 customer
Customer customer = new Customer(name, address, phone);
// 4.调用CustomerDAO的 save(Customer customer) 执行保存操作
customerDAO.save(customer);
// 5.重定向的 success.jsp 页面:使用重定向可以避免表单的重复提交问题
response.sendRedirect("success.jsp");
}
newcustomer.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <% Object msg = request.getAttribute("message"); if (msg != null) { %> <br> <font color="red"><%=msg%></font> <br> <br> <% } %> <form action="addCustomer.do" method="post"> <table> <tr> <td>CustomerNam:</td> <td><input type="text" name="name" value="<%=request.getParameter("name") == null ? "" : request.getParameter("name")%>" /></td> </tr> <tr> <td>Address:</td> <td><input type="text" name="address" value="<%=request.getParameter("address") == null ? "" : request.getParameter("address")%>" /></td> </tr> <tr> <td>Phone:</td> <td><input type="text" name="phone" value="<%=request.getParameter("phone") == null ? "" : request.getParameter("phone")%>" /></td> </tr> <tr> <td colspan="2"><input type="submit" value="Submit" /></td> </tr> </table> </form> </body> </html>
修改:
先显示(SELECT 操作)修改的页面,再进行修改(update)
显示修改页面
Update 的超链接:<a href="edit.do?id=<%= customer.getId() %>">UPDATE</a>
edit 方法:
private void edit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String forwardPath = "/error.jsp";// 初始值 // 1.获取请求参数 id String idStr = request.getParameter("id"); // 2.调用CustomerDAO 的 customerDAO.get(id) 获取 id 对应的Customer 对象customer try { Customer customer = customerDAO.get(Integer.parseInt(idStr)); if (customer != null) {// 当customer为null是转到 error.jsp forwardPath = "/updatecustomer.jsp"; // 3.将customer放入request 中 request.setAttribute("customer", customer); } } catch (Exception e) { } // 4.响应updatecustomer.jsp 页面: 转发 request.getRequestDispatcher(forwardPath).forward(request, response); }
JSP 页面:
获取请求域中的 Customer 对象,调用对应的字段的 get 方法来显示值。
使用隐藏域来保存要修改的 Customer 对象的 id:<input type="hidden" name="id" value=“<%= customer.getId() %>"/>
使用隐藏域来保存 oldName:<input type="hidden" name=“oldName" value=“<%= customer.getName() %>"/>
关于隐藏域:和其他的表单域一样可以被提交到服务器,只不过在额页面上不显示
提交到 update.do
CustomerServlet
package com.aff.mvcapp.servlet; import java.io.IOException; import java.lang.reflect.Method; import java.util.List; 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 com.aff.mvcapp.dao.CriteriaCustomer; import com.aff.mvcapp.dao.CustomerDAO; import com.aff.mvcapp.dao.impl.CustomerDAOImpl; import com.aff.mvcapp.domian.Customer; @WebServlet("/customerServlet") public class CustomerServlet extends HttpServlet { private static final long serialVersionUID = 1L; private CustomerDAO customerDAO = new CustomerDAOImpl(); protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 1. 获取ServletPath: /edit.do 或 addCustomer.do String servletPath = request.getServletPath(); // 2.去除 / 和 .do 得到类似于 edit 或 addCustomer 这样的字符串 String methodName = servletPath.substring(1); methodName = methodName.substring(0, methodName.length() - 3); try { // 3.利用反射获取 methodName 对应的方法 Method method = getClass().getDeclaredMethod(methodName, HttpServletRequest.class, HttpServletResponse.class); // 4.利用反射调用对应的方法 method.invoke(this, request, response); } catch (Exception e) { // e.printStackTrace(); // 可以有一些响应 response.sendRedirect("error.jsp"); } } private void addCustomer(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 1.获取表单参数:name address phone String name = request.getParameter("name"); String address = request.getParameter("address"); String phone = request.getParameter("phone"); // 2.检验 name 是否被占用 // 2.1调用CustomerDAO的getCountWithName(String name) 获取 name 在数据库中是否存在 long count = customerDAO.getCountWithName(name); // 2.2若返回值大于0,则响应 newcustomer.jsp 页面, 通过转发的方式响应newcustomer.jsp if (count > 0) { // 2.2.1要求页面显示一个错误消息: 用户名 name已经被占用,请重新选择, // 在request中放入一个属性message :用户名 name 已经被占用,请重新选择! // 在页面通过request.getAttribute("message")的方式显示 request.setAttribute("message", "用户名 " + name + "已经被占用,请重新选择"); // 2.2.2 newcustomer.jsp 的表单可以回显 // 通过value="<%=request.getParameter("name") == null ? "" : // request.getParameter("name") %>"进行回显 // 2.2.3结束方法:return request.getRequestDispatcher("/newcustomer.jsp").forward(request, response); return; } // 3.若验证通过,把表单参数封装为一个Customer 对象 customer Customer customer = new Customer(name, address, phone); // 4.调用CustomerDAO的 save(Customer customer) 执行保存操作 customerDAO.save(customer); // 5.重定向的 success.jsp 页面:使用重定向可以避免表单的重复提交问题 response.sendRedirect("success.jsp"); } private void edit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String forwardPath = "/error.jsp";// 初始值 // 1.获取请求参数 id String idStr = request.getParameter("id"); // 2.调用CustomerDAO 的 customerDAO.get(id) 获取 id 对应的Customer 对象customer try { Customer customer = customerDAO.get(Integer.parseInt(idStr)); if (customer != null) {// 当customer为null是转到 error.jsp forwardPath = "/updatecustomer.jsp"; // 3.将customer放入request 中 request.setAttribute("customer", customer); } } catch (Exception e) { } // 4.响应updatecustomer.jsp 页面: 转发 request.getRequestDispatcher(forwardPath).forward(request, response); } private void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 1.获取表单参数:id,name,addres, phone, oldName String id = request.getParameter("id"); String name = request.getParameter("name"); String address = request.getParameter("address"); String phone = request.getParameter("phone"); String oldName = request.getParameter("oldName"); // 2.检查name是否被占用 // 2.比较name和oldName 是否相同,若相同说明 name可用 // 2.1若不相同, 则调用CustomerDAO 的 getCountWithName(String name) 获取 name在数据库中是否存在 if (!oldName.equalsIgnoreCase(name)) { long count = customerDAO.getCountWithName(name); if (count > 0) { // 2.2若返回值大于0,则响应 updatecustomer.jsp 页面, // 通过转发的方式响应updatecustomer.jsp // 2.2.1要求页面显示一个错误消息: 用户名 name已经被占用,请重新选择, // 在request中放入一个属性message :用户名 name 已经被占用,请重新选择! // 在页面通过request.getAttribute("message")的方式显示 request.setAttribute("message", "用户名" + name + "已经被占用,请重新选择!"); // 2.2.2 updatecustomer.jsp 的表单可以回显 // address, phone 显示提交表单的新的值,而 name 显示oldName, 而不是新提交的 name // 2.2.3结束方法:return request.getRequestDispatcher("/updatecustomer.jsp").forward(request, response); return; } } //3.若验证通过,则把表单参数封装为一个Customer 对象 customer Customer customer = new Customer(name, address, phone); customer.setId(Integer.parseInt(id));//表单过来的 安全的 //4.调用CustomerDAO 的 update(Customer customer) 执行更新操作 customerDAO.update(customer); //5.重定向到 query.do response.sendRedirect("query.do"); }
private void query(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String name = request.getParameter("name"); String address = request.getParameter("address"); String phone = request.getParameter("phone"); CriteriaCustomer cc = new CriteriaCustomer(name, address, phone); // 1.调用 CustomerDAO 的 getForListWithCriteriaCustomer() 得到 Customer 的集合 List<Customer> customers = customerDAO.getForListWithCriteriaCustomer(cc); // 2.把 Customer 的集合放入 request 中 request.setAttribute("customers", customers); // 3.转发页面到 index.jsp 中( 不能使用重定向) request.getRequestDispatcher("/index.jsp").forward(request, response); } private void delete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String idstr = request.getParameter("id"); int id = 0; // try-catch的作用 , 防止恶意的输入, idStr 不能转为int类型,若出异常 id直接为0 try { id = Integer.parseInt(idstr); customerDAO.delete(id); } catch (Exception e) { } response.sendRedirect("query.do"); } }
updatecustomer.jsp
<%@page import="com.aff.mvcapp.domian.Customer"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <% Object msg = request.getAttribute("message"); if (msg != null) { %> <br> <font color="red"><%=msg%></font> <br> <br> <% } %> <% String id = null; String oldName = null; String name = null; String address = null; String phone = null;
Customer customer = (Customer) request.getAttribute("customer"); if(customer != null){ id = customer.getId()+""; name = customer.getName(); oldName = customer.getName(); address = customer.getAddress(); phone = customer.getPhone(); }else{ id = request.getParameter("id");//旧的 name = request.getParameter("oldName");//旧的 oldName = request.getParameter("oldName");//旧的 address = request.getParameter("address");//新的 phone = request.getParameter("phone");//新的 } %> <form action="update.do" method="post"> <input type="hidden" name="id" value="<%=id%>" /> <input type="hidden" name="oldName" value="<%=oldName%>" /> <table> <tr> <td>CustomerNam:</td> <td><input type="text" name="name" value="<%=name%>" /></td> </tr> <tr> <td>Address:</td> <td><input type="text" name="address" value="<%=address%>" /></td> </tr> <tr> <td>Phone:</td> <td><input type="text" name="phone" value="<%=phone%>" /></td> </tr> <tr> <td colspan="2"><input type="submit" value="Submit" /></td> </tr> </table> </form> </body> </html>
index.jsp
<%@page import="com.aff.mvcapp.domian.Customer"%> <%@page import="java.util.List"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <script type="text/javascript" src="scripts/jquery-1.12.3.js"></script> <script type="text/javascript"> $(function() { $(".delete").click(function() { //找到tr的第二个td也就是name,再获取它的value值 var content = $(this).parent().parent().find("td:eq(1)").text(); var flag = confirm("确定要删除" + content + "的信息吗") return flag; }); }); </script> </head> <body> <form action="query.do" method="post"> <table> <tr> <td>CustomerNam:</td> <td><input type="text" name="name" /></td> </tr> <tr> <td>Address:</td> <td><input type="text" name="address" /></td> </tr> <tr> <td>Phone:</td> <td><input type="text" name="phone" /></td> </tr> <tr> <td><input type="submit" value="Query" /></td> <td><a href="newcustomer.jsp">Add New Customer</a></td> </tr> </table> </form> <br /> <br /> <br /> <br /> <% List<Customer> customers = (List<Customer>) request.getAttribute("customers"); if (customers != null && customers.size() > 0) { %> <hr> <br> <br> <table border="1" cellpadding="10" cellspacing="0"> <tr> <td>ID</td> <td>CustomersName</td> <td>Address</td> <td>Phone</td> <td>UPDATEDELETE</td> </tr> <% for (Customer customer : customers) { %> <tr> <td><%=customer.getId()%></td> <td><%=customer.getName()%></td> <td><%=customer.getAddress()%></td> <td><%=customer.getPhone()%></td> <td><a href="edit.do?id=<%=customer.getId()%>">UPDATE</a> <a href="delete.do?id=<%=customer.getId()%>" class="delete">DELETE</a> </td> </tr> <% } %> </table> <% } %> </body> </html>