第1章 Servlet基礎
1-1 Servlet概述
Servlet基礎
- 什麼是Servlet
- Tomcat容器等級
- 手工編寫第一個Servlet
- 使用MyEclipse編寫Servlet
- Servlet聲明週期
- Servlet獲取九大內置對象
- Servlet與表單
- Servlet路徑跳轉
- 階段項目
什麼是Servlet 先有JSP還是先有Servlet？
我可以負責任的告訴大家先有Servlet。沒錯，Jsp的前身就是Servlet。
Servlet是在服務端運行的小程序。一個Servlet就是一個Java類，並且
可以通過“請求-響應”編程模型來訪問的這個駐留在服務器內裏的Servlet
程序。
1-2 Tomcat容器等級
Tomcat容器等級
Tomcat的容器分爲四個等級，Servlet的容器管理Context容器，一個
Context對應一個Web工程。
Tomcat->Container容器->Engine->HOST->Servlet容器->Context
1-3 手工編寫第一個Servlet
手工編寫第一個Servlet
- 繼承HttpServlet
- 重寫doGet()或者doPost()方法
- 在web.xml中註冊Servlet
Servlet ->三個方法Init() service() destory()
|
GenericServlet(Abstract Class) ->與協議無關的Servlet
|
HttpServlet(Abstract Class) ->實現了http協議的servlet
|
自定義Servlet ->一般重寫（覆蓋）doGet()，doPost()方法
public class HelloServlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest requset, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("處理Get()請求...");
PrintWriter out = response.getWriter();
response.setContentType("text/html;charset=utf-8");
out.println("<Strong>Hello Servlet!</Strong><br>");
}
@Override
protected void doPost(HttpServletRequest requset, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("處理Post()請求...");
PrintWriter out = response.getWriter();
response.setContentType("text/html;charset=utf-8");
out.println("<Strong>Hello Servlet!</Strong><br>");
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>servlet.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/servlet/HelloServlet</url-pattern>
</servlet-mapping>
</web-app><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>第一個Servlet小例子</h1>
<hr>
<a href="servlet/HelloServlet">Get方式請求HelloServlet</a><br>
<form action="servlet/HelloServlet" method="post">
<input type="submit" value="Post方式請求HelloServlet"/>
</form>
</body>
</html>1-4 使用MyEclipse編寫Servlet
使用M有Eclipse編寫第一個Servlet
- src->new->Servlet
- 重寫doGet()或者doPost()
- 部署運行
public class HelloServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public HelloServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("處理get請求...");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println("<strong>Hello Servlet!</strong>");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("處理post請求...");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println("<strong>Hello Servlet!</strong>");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>servlet.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/servlet/HelloServlet</url-pattern>
</servlet-mapping>
</web-app><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>第一個Servlet小例子</h1>
<hr>
<a href="servlet/HelloServlet">Get方式請求HelloServlet</a><br>
<form action="servlet/HelloServlet" method="post">
<input type="submit" value="Post方式請求HelloServlet"/>
</form>
</body>
</html>
1-5 練習題
假設在helloapp應用中有一個HelloServlet類，它在 web.xml文件中的配置如下:
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>org.javathinker.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/hello</url-pattern>
</servlet-mapping> 那麼在瀏覽器端訪問HelloServlet的URL是什麼?
http://localhost:8080/helloapp/hello
localhost是服務器主機名，也可以是IP地址127.0.0.1；8080是tomcat服務器的端口號；helloapp是web工程的上下文地址ContexRoot（一般情況下與web工程名一致）；最後是標籤中的內容。
1-6 Servlet執行流程和生命週期
- servlet執行流程
- 使用MyEclipse編寫第一個Servlet
Get方式請求HelloServlet -> Get方式請求HelloServlet
/servlet/HelloServlet
servlet.HelloServlet
public class HelloServlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest requset, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("處理Get()請求...");Servlet生命週期
- 舒適化階段，調用init()方法
- 響應客戶端請求階段，調用service()方法。由service()方法根據提交
方式選擇執行doGet()或者doPost()方法。 - 終止階段，調用destroy()方法。
1-7 練習題
在Java EE中Servlet是在服務器端運行以處理客戶端請求而做出的響應的程序。下列選項中屬於Servlet生命週期階段的是
加載和實例化、初始化、服務和銷燬
1-8 練習題
編寫Servlet的doPost方法時，需要拋出異常爲
ServletException， IOException
1-9 Tomcat裝載Servlet的三種情況
在下列時刻Servlet容器裝載Servlet
- Servlet容器啓動時刻自動裝載某些Servlet，實現它只需在web.xml文件中的
之間添加如下代碼：1
數字越小表示優先級別越高。 - 在Servlet容器啓動後，客戶端首次向Servlet發送請求。
- Servlet類文件被更新後，重新裝載Servlet。
public class TestServlet1 extends HttpServlet {
/**
* Constructor of the object.
*/
public TestServlet1() {
System.out.println("TestServlet1構造方法被執行....");
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
System.out.println("TestServlet1銷燬方法被執行....");
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("TestServlet1的doGet()方法被執行...");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println("<h1>大家好，我是TestServlet1！</h1>");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("TestServlet1的doPost()方法被執行...");
doGet(request,response); //讓doPost()執行與doGet()相同的操作。
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
System.out.println("TestServlet1的初始化方法被執行....");
}
}public class TestServlet2 extends HttpServlet {
/**
* Constructor of the object.
*/
public TestServlet2() {
System.out.println("TestServlet2構造方法被執行....");
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
System.out.println("TestServlet2銷燬方法被執行....");
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("TestServlet2的doGet()方法被執行...");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println("<h1>您好，我是TestServlet2</h1>");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("TestServlet2的doPost()方法被執行...");
doGet(request,response); //讓doPost()執行與doGet()相同的操作
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
System.out.println("TestServlet2的初始化方法被執行....");
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>TestServlet1</servlet-name>
<servlet-class>servlet.TestServlet1</servlet-class>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>TestServlet2</servlet-name>
<servlet-class>servlet.TestServlet2</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>TestServlet1</servlet-name>
<url-pattern>/servlet/TestServlet1</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>TestServlet2</servlet-name>
<url-pattern>/servlet/TestServlet2</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>Servlet生命週期</h1>
<hr>
<a href="servlet/TestServlet1">以Get方式請求TestServlet1</a>
</body>
</html>
1-10 Servlet與JSP內置對象的對應關係
| JSP對象 | 怎麼獲得 |
|---|---|
| out | resp.getWriter |
| request | service方法中req參數 |
| response | service方法中resp參數 |
| session | req.getSession()函數 |
| application | getServletContext()函數 |
| exception | Throwable |
| page | this |
| pageContext | PageContext |
| Config | getServletConfig函數 |
1-11 Servlet獲取表單數據
//用戶實體類
public class Users {
private String username; //用戶名
private String mypassword; //密碼
private String email; //電子郵箱
private String gender; //性別
private Date birthday; //出生日期
private String[] favorites; //愛好
private String introduce; //自我介紹
private boolean flag; //是否接受協議
public Users()
{
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getMypassword() {
return mypassword;
}
public void setMypassword(String mypassword) {
this.mypassword = mypassword;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String[] getFavorites() {
return favorites;
}
public void setFavorites(String[] favorites) {
this.favorites = favorites;
}
public String getIntroduce() {
return introduce;
}
public void setIntroduce(String introduce) {
this.introduce = introduce;
}
public boolean isFlag() {
return flag;
}
public void setFlag(boolean flag) {
this.flag = flag;
}
}public class RegServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public RegServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
Users u = new Users();
String username,mypassword,gender,email,introduce,isAccept;
Date birthday;
String[] favorites;
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
try
{
username = request.getParameter("username");
mypassword = request.getParameter("mypassword");
gender = request.getParameter("gender");
email = request.getParameter("email");
introduce = request.getParameter("introduce");
birthday = sdf.parse(request.getParameter("birthday"));
if(request.getParameterValues("isAccpet")!=null)
{
isAccept = request.getParameter("isAccept");
}
else
{
isAccept = "false";
}
//用來獲取多個複選按鈕的值
favorites = request.getParameterValues("favorite");
u.setUsername(username);
u.setMypassword(mypassword);
u.setGender(gender);
u.setEmail(email);
u.setFavorites(favorites);
u.setIntroduce(introduce);
if(isAccept.equals("true"))
{
u.setFlag(true);
}
else
{
u.setFlag(false);
}
u.setBirthday(birthday);
//把註冊成功的用戶對象保存在session中
request.getSession().setAttribute("regUser", u);
//跳轉到註冊成功頁面
request.getRequestDispatcher("../userinfo.jsp").forward(request,response);
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>RegServlet</servlet-name>
<servlet-class>servlet.RegServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RegServlet</servlet-name>
<url-pattern>/servlet/RegServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'reg.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<style type="text/css">
.label{
width: 20%
}
.controler{
width: 80%
}
</style>
<script type="text/javascript" src="js/Calendar3.js"></script>
</head>
<body>
<h1>用戶註冊</h1>
<hr>
<form name="regForm" action="servlet/RegServlet" method="post" >
<table border="0" width="800" cellspacing="0" cellpadding="0">
<tr>
<td class="lalel">用戶名：</td>
<td class="controler"><input type="text" name="username" /></td>
</tr>
<tr>
<td class="label">密碼：</td>
<td class="controler"><input type="password" name="mypassword" ></td>
</tr>
<tr>
<td class="label">確認密碼：</td>
<td class="controler"><input type="password" name="confirmpass" ></td>
</tr>
<tr>
<td class="label">電子郵箱：</td>
<td class="controler"><input type="text" name="email" ></td>
</tr>
<tr>
<td class="label">性別：</td>
<td class="controler"><input type="radio" name="gender" checked="checked" value="Male">男<input type="radio" name="gender" value="Female">女</td>
</tr>
<tr>
<td class="label">出生日期：</td>
<td class="controler">
<input name="birthday" type="text" id="control_date" size="10"
maxlength="10" onclick="new Calendar().show(this);" readonly="readonly" />
</td>
</tr>
<tr>
<td class="label">愛好：</td>
<td class="controler">
<input type="checkbox" name="favorite" value="nba"> NBA
<input type="checkbox" name="favorite" value="music"> 音樂
<input type="checkbox" name="favorite" value="movie"> 電影
<input type="checkbox" name="favorite" value="internet"> 上網
</td>
</tr>
<tr>
<td class="label">自我介紹：</td>
<td class="controler">
<textarea name="introduce" rows="10" cols="40"></textarea>
</td>
</tr>
<tr>
<td class="label">接受協議：</td>
<td class="controler">
<input type="checkbox" name="isAccept" value="true">是否接受霸王條款
</td>
</tr>
<tr>
<td colspan="2" align="center">
<input type="submit" value="註冊"/>
<input type="reset" value="取消"/>
</td>
</tr>
</table>
</form>
</body>
</html><%@ page language="java" import="java.util.*,java.text.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'userinfo.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<style type="text/css">
.title{
width: 30%;
background-color: #CCC;
font-weight: bold;
}
.content{
width:70%;
background-color: #CBCFE5;
}
</style>
</head>
<body>
<h1>用戶信息</h1>
<hr>
<center>
<jsp:useBean id="regUser" class="entity.Users" scope="session"/>
<table width="600" cellpadding="0" cellspacing="0" border="1">
<tr>
<td class="title">用戶名：</td>
<td class="content"> <jsp:getProperty name="regUser" property="username"/></td>
</tr>
<tr>
<td class="title">密碼：</td>
<td class="content"> <jsp:getProperty name="regUser" property="mypassword"/></td>
</tr>
<tr>
<td class="title">性別：</td>
<td class="content"> <jsp:getProperty name="regUser" property="gender"/></td>
</tr>
<tr>
<td class="title">E-mail：</td>
<td class="content"> <jsp:getProperty name="regUser" property="email"/></td>
</tr>
<tr>
<td class="title">出生日期：</td>
<td class="content">
<%
SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日");
String date = sdf.format(regUser.getBirthday());
%>
<%=date%>
</td>
</tr>
<tr>
<td class="title">愛好：</td>
<td class="content">
<%
String[] favorites = regUser.getFavorites();
for(String f:favorites)
{
%>
<%=f%>
<%
}
%>
</td>
</tr>
<tr>
<td class="title">自我介紹：</td>
<td class="content"> <jsp:getProperty name="regUser" property="introduce"/></td>
</tr>
<tr>
<td class="title">是否介紹協議：</td>
<td class="content"> <jsp:getProperty name="regUser" property="flag"/></td>
</tr>
</table>
</center>
</body>
</html>1-12 練習題
在J2EE中,對於HttpServlet類的描述,不正確的是
我們自己編寫的Servlet繼承了HttpServlet類,一般只需覆蓋doPost或者doGet方法,不必覆蓋service( )方法,因爲一個sevrvice( )方法是空的。
HttpServlet類擴展了GenericServlet類,實現了GenericServlet類的抽象方法
sevrvice( )
HttpServlet類有兩個sevrvice( )方法
我們自己編寫的Servlet繼承了HttpServlet類,一般只需覆蓋doPost或者doGet方法,不必覆蓋sevrvice( )方法.因爲一個sevrvice( )方法會調用doPost或者doGet方法
該選項描述錯誤，不覆蓋service()方法，不是因爲該方法是空，而是因爲sevrvice( )方法會調用doPost或者doGet方法。
1-13 Servlet路徑跳轉
Servlet路徑跳轉
- 絕對路徑：放之四海而皆準的路徑
- 相對路徑：相對於當前資源的路徑
public class HelloServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public HelloServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println("<h1>您好，我是HelloServlet!</h1>");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}public class TestServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public TestServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//請求重定向方式跳轉到test.jsp,當前路徑是ServletPathDirection/servlet/
//response.sendRedirect("test.jsp");
//使用request.getContextPath獲得上下文對象
//response.sendRedirect(request.getContextPath()+"/test.jsp");
//服務器內部跳轉,這裏的斜線表示項目的根目錄
//request.getRequestDispatcher("/test.jsp").forward(request, response);
request.getRequestDispatcher("../test.jsp").forward(request, response);
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>servlet.HelloServlet</servlet-class>
</servlet>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>TestServlet</servlet-name>
<servlet-class>servlet.TestServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<!--url-pattern處必須以/開頭，這裏的/表示項目的根目錄 -->
<url-pattern>/servlet/HelloServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>TestServlet</servlet-name>
<url-pattern>/servlet/TestServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>Servlet路徑跳轉</h1>
<hr>
<!--使用相對路徑訪問HelloServlet -->
<!-- /servlet/HelloServlet 第一個/表示服務器的根目錄 -->
<a href="servlet/HelloServlet">訪問HelloServlet!</a><br>
<!-- 使用絕對路徑 訪問HelloServlet,可以使用path變量:path變量表示項目的根目錄-->
<a href="<%=path%>/servlet/HelloServlet">訪問HelloServlet!</a><br>
<!--表單中action的URL地址寫法，與超鏈接方式完全相同。 -->
<a href="servlet/TestServlet">訪問TestServlet,跳轉到Test.jsp</a>
</body>
</html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>Test.jsp</h1>
<hr>
</body>
</html>1-14 階段案例
//用戶類
public class Users {
private String username;
private String password;
public Users()
{
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}public class LoginServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public LoginServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Users u = new Users();
String username = request.getParameter("username");
String password = request.getParameter("password");
u.setUsername(username);
u.setPassword(password);
//判斷用戶名和密碼是否合法
if(u.getUsername().equals("admin")&&u.getPassword().equals("admin"))
{
request.getSession().setAttribute("loginUser", username);
response.sendRedirect(request.getContextPath()+"/login_success.jsp");
}
else
{
response.sendRedirect(request.getContextPath()+"/login_failure.jsp");
}
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/servlet/LoginServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
</web-app>
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
<!-- Page title -->
<title>imooc - Login</title>
<!-- End of Page title -->
<!-- Libraries -->
<link type="text/css" href="css/login.css" rel="stylesheet" />
<link type="text/css" href="css/smoothness/jquery-ui-1.7.2.custom.html" rel="stylesheet" />
<script type="text/javascript" src="js/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="js/easyTooltip.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.7.2.custom.min.js"></script>
<!-- End of Libraries -->
</head>
<body>
<div id="container">
<div class="logo">
<a href="#"><img src="assets/logo.png" alt="" /></a>
</div>
<div id="box">
登錄失敗！請檢查用戶或者密碼!<br>
<a href="login.jsp">返回登錄</a>
</div>
</div>
</body>
</html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
<!-- Page title -->
<title>imooc - Login</title>
<!-- End of Page title -->
<!-- Libraries -->
<link type="text/css" href="css/login.css" rel="stylesheet" />
<link type="text/css" href="css/smoothness/jquery-ui-1.7.2.custom.html" rel="stylesheet" />
<script type="text/javascript" src="js/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="js/easyTooltip.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.7.2.custom.min.js"></script>
<!-- End of Libraries -->
</head>
<body>
<div id="container">
<div class="logo">
<a href="#"><img src="assets/logo.png" alt="" /></a>
</div>
<div id="box">
<%
String loginUser = "";
if(session.getAttribute("loginUser")!=null)
{
loginUser = session.getAttribute("loginUser").toString();
}
%>
歡迎您<font color="red"><%=loginUser%></font>,登錄成功！
</div>
</div>
</body>
</html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
<!-- Page title -->
<title>imooc - Login</title>
<!-- End of Page title -->
<!-- Libraries -->
<link type="text/css" href="css/login.css" rel="stylesheet" />
<link type="text/css" href="css/smoothness/jquery-ui-1.7.2.custom.html" rel="stylesheet" />
<script type="text/javascript" src="js/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="js/easyTooltip.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.7.2.custom.min.js"></script>
<!-- End of Libraries -->
</head>
<body>
<div id="container">
<div class="logo">
<a href="#"><img src="assets/logo.png" alt="" /></a>
</div>
<div id="box">
<form action="servlet/LoginServlet" method="post">
<p class="main">
<label>用戶名: </label>
<input name="username" value="" />
<label>密碼: </label>
<input type="password" name="password" value="">
</p>
<p class="space">
<input type="submit" value="登錄" class="login" style="cursor: pointer;"/>
</p>
</form>
</div>
</div>
</body>
</html>第2章 應用MVC架構實現項目
2-1 獲取初始化參數
Servlet高級
- 獲取初始化參數
- MVC設計模式
- Model2簡介
- 階段項目
獲取初始化參數
在web.xml中配置Servlet時，可以配置一些初始化參數。而在Servlet中可以
通過ServletConfig接口提供的方法來獲取這些參數。
public class GetInitParameterServlet extends HttpServlet {
private String username;//用戶名
private String password; //密碼
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
/**
* Constructor of the object.
*/
public GetInitParameterServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.println("<h2>"+"用戶名："+this.getUsername()+"</h2>");
out.println("<h2>"+"密碼："+this.getPassword()+"</h2>");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
this.setUsername(this.getInitParameter("username"));
this.setPassword(this.getInitParameter("password"));
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<display-name></display-name>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>GetInitParameterServlet</servlet-name>
<servlet-class>servlet.GetInitParameterServlet</servlet-class>
<init-param>
<param-name>username</param-name>
<param-value>admin</param-value>
</init-param>
<init-param>
<param-name>password</param-name>
<param-value>123456</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>GetInitParameterServlet</servlet-name>
<url-pattern>/servlet/GetInitParameterServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1>獲取初始化參數演示案例</h1>
<hr>
<a href="servlet/GetInitParameterServlet">獲取初始化參數Servlet</a>
</body>
</html>2-2 練習題
從以下哪一個選項中可以獲得Servlet的初始化參數
ServletConfig
2-3 MVC模型介紹
MVC
MVC模式：MVC（Model、View、Controller），是軟件開發過程中比較流行的
設計思想。旨在分離模型、控制、視圖。是一種分層思想的體現。
2-4 Model2模型介紹
Model1簡介
瀏覽器 - JSP JavaBean - 企業數據庫
Model2簡介
JSP(V)-Servlet(C)-JavaBean(M)-DB
2-5 項目概述
使用servlet技術實現購物車效果
2-6 界面原型效果及界面開發步驟
MVC模型實現（Jsp+Servlet+dao）
創建購物車類
編寫Servlet
創建頁面層
2-7 購物車類的設計
購物車類(Cart)的設計
- 添加
- 刪除
- 計算總金額
//購物車類
public class Cart {
//購買商品的集合
private HashMap<Items,Integer> goods;
//購物車的總金額
private double totalPrice;
//構造方法
public Cart(){
goods = new HashMap<Items,Integer>();
totalPrice = 0.0;
}
public HashMap<Items, Integer> getGoods() {
return goods;
}
public void setGoods(HashMap<Items, Integer> goods) {
this.goods = goods;
}
public double getTotalPrice() {
return totalPrice;
}
public void setTotalPrice(double totalPrice) {
this.totalPrice = totalPrice;
}
//添加商品進購物車
public boolean addGoodsInCart(Items item,int number){
goods.put(item, number);
calTotalPrice();//重新計算購物車的總金額
return true;
}
//刪除商品的方法
public boolean removeGoodsFromCart(Items item){
goods.remove(item);
calTotalPrice();//重新計算購物車的總金額
return true;
}
//統計購物車的總金額
public double calTotalPrice(){
double sum = 0.0;
Set<Items> keys = goods.keySet();
Iterator<Items> it = keys.iterator();
while(it.hasNext()){
Items i = it.next();
sum += i.getPrice()*goods.get(i);
}
this.setTotalPrice(sum);//設置購物車的總金額
return sum;
}
}2-8 測試購物車類
//購物車類
public class Cart {
// 購買商品的集合
private HashMap<Items, Integer> goods;
// 購物車的總金額
private double totalPrice;
// 構造方法
public Cart() {
goods = new HashMap<Items, Integer>();
totalPrice = 0.0;
}
public HashMap<Items, Integer> getGoods() {
return goods;
}
public void setGoods(HashMap<Items, Integer> goods) {
this.goods = goods;
}
public double getTotalPrice() {
return totalPrice;
}
public void setTotalPrice(double totalPrice) {
this.totalPrice = totalPrice;
}
// 添加商品進購物車
public boolean addGoodsInCart(Items item, int number) {
goods.put(item, number);
calTotalPrice();// 重新計算購物車的總金額
return true;
}
// 刪除商品的方法
public boolean removeGoodsFromCart(Items item) {
goods.remove(item);
calTotalPrice();// 重新計算購物車的總金額
return true;
}
// 統計購物車的總金額
public double calTotalPrice() {
double sum = 0.0;
Set<Items> keys = goods.keySet();
Iterator<Items> it = keys.iterator();
while (it.hasNext()) {
Items i = it.next();
sum += i.getPrice() * goods.get(i);
}
this.setTotalPrice(sum);// 設置購物車的總金額
return sum;
}
public static void main(String[] args) {
// 先創建兩個商品對象
Items i1 = new Items(1, "沃特籃球鞋", "溫州", 200, 500, "001.jpg");
Items i2 = new Items(2, "李寧運動鞋", "廣州", 300, 500, "002.jpg");
Items i3 = new Items(1, "沃特籃球鞋", "溫州", 200, 500, "001.jpg");
Cart c = new Cart();
c.addGoodsInCart(i1, 1);
c.addGoodsInCart(i2, 2);
// 再次購買沃特籃球鞋，購買3雙
c.addGoodsInCart(i3, 3);
// 變量購物商品的集合
Set<Map.Entry<Items, Integer>> items = c.getGoods().entrySet();
for (Map.Entry<Items, Integer> obj : items) {
System.out.println(obj);
}
System.out.println("購物車的總金額：" + c.getTotalPrice());
}
}2-9 如何保證不添加重複商品進購物車
//購物車類
public class Cart {
//購買商品的集合
private HashMap<Items,Integer> goods;
//購物車的總金額
private double totalPrice;
//構造方法
public Cart()
{
goods = new HashMap<Items,Integer>();
totalPrice = 0.0;
}
public HashMap<Items, Integer> getGoods() {
return goods;
}
public void setGoods(HashMap<Items, Integer> goods) {
this.goods = goods;
}
public double getTotalPrice() {
return totalPrice;
}
public void setTotalPrice(double totalPrice) {
this.totalPrice = totalPrice;
}
//添加商品進購物車的方法
public boolean addGoodsInCart(Items item ,int number)
{
if(goods.containsKey(item))
{
goods.put(item, goods.get(item)+number);
}
else
{
goods.put(item, number);
}
calTotalPrice(); //重新計算購物車的總金額
return true;
}
//刪除商品的方法
public boolean removeGoodsFromCart(Items item)
{
goods.remove(item);
calTotalPrice(); //重新計算購物車的總金額
return true;
}
//統計購物車的總金額
public double calTotalPrice()
{
double sum = 0.0;
Set<Items> keys = goods.keySet(); //獲得鍵的集合
Iterator<Items> it = keys.iterator(); //獲得迭代器對象
while(it.hasNext())
{
Items i = it.next();
sum += i.getPrice()* goods.get(i);
}
this.setTotalPrice(sum); //設置購物車的總金額
return this.getTotalPrice();
}
public static void main(String[] args) {
//先創建兩個商品對象
Items i1 = new Items(1,"沃特籃球鞋","溫州",200,500,"001.jpg");
Items i2 = new Items(2,"李寧運動鞋","廣州",300,500,"002.jpg");
Items i3 = new Items(1,"沃特籃球鞋","溫州",200,500,"001.jpg");
Cart c = new Cart();
c.addGoodsInCart(i1, 1);
c.addGoodsInCart(i2, 2);
//再次購買沃特籃球鞋，購買3雙
c.addGoodsInCart(i3, 3);
//變量購物商品的集合
Set<Map.Entry<Items, Integer>> items= c.getGoods().entrySet();
for(Map.Entry<Items, Integer> obj:items)
{
System.out.println(obj);
}
System.out.println("購物車的總金額："+c.getTotalPrice());
}
}//商品類
public class Items {
private int id; // 商品編號
private String name; // 商品名稱
private String city; // 產地
private int price; // 價格
private int number; // 庫存
private String picture; // 商品圖片
//保留此不帶參數的構造方法
public Items()
{
}
public Items(int id,String name,String city,int price,int number,String picture)
{
this.id = id;
this.name = name;
this.city = city;
this.picture = picture;
this.price = price;
this.number = number;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
public int getNumber() {
return number;
}
public void setNumber(int number) {
this.number = number;
}
public String getPicture() {
return picture;
}
public void setPicture(String picture) {
this.picture = picture;
}
@Override
public int hashCode() {
// TODO Auto-generated method stub
return this.getId()+this.getName().hashCode();
}
@Override
public boolean equals(Object obj) {
// TODO Auto-generated method stub
if(this==obj)
{
return true;
}
if(obj instanceof Items)
{
Items i = (Items)obj;
if(this.getId()==i.getId()&&this.getName().equals(i.getName()))
{
return true;
}
else
{
return false;
}
}
else
{
return false;
}
}
public String toString()
{
return "商品編號："+this.getId()+",商品名稱："+this.getName();
}
}2-10 添加商品進購物車
2-11 顯示購物車
2-12 商品刪除
//商品的業務邏輯類
public class ItemsDAO {
// 獲得所有的商品信息
public ArrayList<Items> getAllItems() {
Connection conn = null;
PreparedStatement stmt = null;
ResultSet rs = null;
ArrayList<Items> list = new ArrayList<Items>(); // 商品集合
try {
conn = DBHelper.getConnection();
String sql = "select * from items;"; // SQL語句
stmt = conn.prepareStatement(sql);
rs = stmt.executeQuery();
while (rs.next()) {
Items item = new Items();
item.setId(rs.getInt("id"));
item.setName(rs.getString("name"));
item.setCity(rs.getString("city"));
item.setNumber(rs.getInt("number"));
item.setPrice(rs.getInt("price"));
item.setPicture(rs.getString("picture"));
list.add(item);// 把一個商品加入集合
}
return list; // 返回集合。
} catch (Exception ex) {
ex.printStackTrace();
return null;
} finally {
// 釋放數據集對象
if (rs != null) {
try {
rs.close();
rs = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
// 釋放語句對象
if (stmt != null) {
try {
stmt.close();
stmt = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
}
// 根據商品編號獲得商品資料
public Items getItemsById(int id) {
Connection conn = null;
PreparedStatement stmt = null;
ResultSet rs = null;
try {
conn = DBHelper.getConnection();
String sql = "select * from items where id=?;"; // SQL語句
stmt = conn.prepareStatement(sql);
stmt.setInt(1, id);
rs = stmt.executeQuery();
if (rs.next()) {
Items item = new Items();
item.setId(rs.getInt("id"));
item.setName(rs.getString("name"));
item.setCity(rs.getString("city"));
item.setNumber(rs.getInt("number"));
item.setPrice(rs.getInt("price"));
item.setPicture(rs.getString("picture"));
return item;
} else {
return null;
}
} catch (Exception ex) {
ex.printStackTrace();
return null;
} finally {
// 釋放數據集對象
if (rs != null) {
try {
rs.close();
rs = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
// 釋放語句對象
if (stmt != null) {
try {
stmt.close();
stmt = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
}
//獲取最近瀏覽的前五條商品信息
public ArrayList<Items> getViewList(String list)
{
System.out.println("list:"+list);
ArrayList<Items> itemlist = new ArrayList<Items>();
int iCount=5; //每次返回前五條記錄
if(list!=null&&list.length()>0)
{
String[] arr = list.split(",");
System.out.println("arr.length="+arr.length);
//如果商品記錄大於等於5條
if(arr.length>=5)
{
for(int i=arr.length-1;i>=arr.length-iCount;i--)
{
itemlist.add(getItemsById(Integer.parseInt(arr[i])));
}
}
else
{
for(int i=arr.length-1;i>=0;i--)
{
itemlist.add(getItemsById(Integer.parseInt(arr[i])));
}
}
return itemlist;
}
else
{
return null;
}
}
}//購物車類
public class Cart {
//購買商品的集合
private HashMap<Items,Integer> goods;
//購物車的總金額
private double totalPrice;
//構造方法
public Cart()
{
goods = new HashMap<Items,Integer>();
totalPrice = 0.0;
}
public HashMap<Items, Integer> getGoods() {
return goods;
}
public void setGoods(HashMap<Items, Integer> goods) {
this.goods = goods;
}
public double getTotalPrice() {
return totalPrice;
}
public void setTotalPrice(double totalPrice) {
this.totalPrice = totalPrice;
}
//添加商品進購物車的方法
public boolean addGoodsInCart(Items item ,int number)
{
if(goods.containsKey(item))
{
goods.put(item, goods.get(item)+number);
}
else
{
goods.put(item, number);
}
calTotalPrice(); //重新計算購物車的總金額
return true;
}
//刪除商品的方法
public boolean removeGoodsFromCart(Items item)
{
goods.remove(item);
calTotalPrice(); //重新計算購物車的總金額
return true;
}
//統計購物車的總金額
public double calTotalPrice()
{
double sum = 0.0;
Set<Items> keys = goods.keySet(); //獲得鍵的集合
Iterator<Items> it = keys.iterator(); //獲得迭代器對象
while(it.hasNext())
{
Items i = it.next();
sum += i.getPrice()* goods.get(i);
}
this.setTotalPrice(sum); //設置購物車的總金額
return this.getTotalPrice();
}
public static void main(String[] args) {
//先創建兩個商品對象
Items i1 = new Items(1,"沃特籃球鞋","溫州",200,500,"001.jpg");
Items i2 = new Items(2,"李寧運動鞋","廣州",300,500,"002.jpg");
Items i3 = new Items(1,"沃特籃球鞋","溫州",200,500,"001.jpg");
Cart c = new Cart();
c.addGoodsInCart(i1, 1);
c.addGoodsInCart(i2, 2);
//再次購買沃特籃球鞋，購買3雙
c.addGoodsInCart(i3, 3);
//變量購物商品的集合
Set<Map.Entry<Items, Integer>> items= c.getGoods().entrySet();
for(Map.Entry<Items, Integer> obj:items)
{
System.out.println(obj);
}
System.out.println("購物車的總金額："+c.getTotalPrice());
}
}//商品類
public class Items {
private int id; // 商品編號
private String name; // 商品名稱
private String city; // 產地
private int price; // 價格
private int number; // 庫存
private String picture; // 商品圖片
//保留此不帶參數的構造方法
public Items()
{
}
public Items(int id,String name,String city,int price,int number,String picture)
{
this.id = id;
this.name = name;
this.city = city;
this.picture = picture;
this.price = price;
this.number = number;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
public int getNumber() {
return number;
}
public void setNumber(int number) {
this.number = number;
}
public String getPicture() {
return picture;
}
public void setPicture(String picture) {
this.picture = picture;
}
@Override
public int hashCode() {
// TODO Auto-generated method stub
return this.getId()+this.getName().hashCode();
}
@Override
public boolean equals(Object obj) {
// TODO Auto-generated method stub
if(this==obj)
{
return true;
}
if(obj instanceof Items)
{
Items i = (Items)obj;
if(this.getId()==i.getId()&&this.getName().equals(i.getName()))
{
return true;
}
else
{
return false;
}
}
else
{
return false;
}
}
public String toString()
{
return "商品編號："+this.getId()+",商品名稱："+this.getName();
}
}public class CartServlet extends HttpServlet {
private String action ; //表示購物車的動作 ,add,show,delete
//商品業務邏輯類的對象
private ItemsDAO idao = new ItemsDAO();
/**
* Constructor of the object.
*/
public CartServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
if(request.getParameter("action")!=null)
{
this.action = request.getParameter("action");
if(action.equals("add")) //如果是添加商品進購物車
{
if(addToCart(request,response))
{
request.getRequestDispatcher("/success.jsp").forward(request, response);
}
else
{
request.getRequestDispatcher("/failure.jsp").forward(request, response);
}
}
if(action.equals("show"))//如果是顯示購物車
{
request.getRequestDispatcher("/cart.jsp").forward(request, response);
}
if(action.equals("delete")) //如果是執行刪除購物車中的商品
{
if(deleteFromCart(request,response))
{
request.getRequestDispatcher("/cart.jsp").forward(request, response);
}
else
{
request.getRequestDispatcher("/cart.jsp").forward(request, response);
}
}
}
}
//添加商品進購物車的方法
private boolean addToCart(HttpServletRequest request, HttpServletResponse response)
{
String id = request.getParameter("id");
String number = request.getParameter("num");
Items item = idao.getItemsById(Integer.parseInt(id));
//是否是第一次給購物車添加商品,需要給session中創建一個新的購物車對象
if(request.getSession().getAttribute("cart")==null)
{
Cart cart = new Cart();
request.getSession().setAttribute("cart",cart);
}
Cart cart = (Cart)request.getSession().getAttribute("cart");
if(cart.addGoodsInCart(item, Integer.parseInt(number)))
{
return true;
}
else
{
return false;
}
}
//從購物車中刪除商品
private boolean deleteFromCart(HttpServletRequest request, HttpServletResponse response)
{
String id = request.getParameter("id");
Cart cart = (Cart)request.getSession().getAttribute("cart");
Items item = idao.getItemsById(Integer.parseInt(id));
if(cart.removeGoodsFromCart(item))
{
return true;
}
else
{
return false;
}
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}public class DBHelper {
private static final String driver = "com.mysql.jdbc.Driver"; //數據庫驅動
//連接數據庫的URL地址
private static final String url="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8";
private static final String username="root";//數據庫的用戶名
private static final String password="root";//數據庫的密碼
private static Connection conn=null;
//靜態代碼塊負責加載驅動
static
{
try
{
Class.forName(driver);
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
//單例模式返回數據庫連接對象
public static Connection getConnection() throws Exception
{
if(conn==null)
{
conn = DriverManager.getConnection(url, username, password);
return conn;
}
return conn;
}
public static void main(String[] args) {
try
{
Connection conn = DBHelper.getConnection();
if(conn!=null)
{
System.out.println("數據庫連接正常！");
}
else
{
System.out.println("數據庫連接異常！");
}
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
}<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>CartServlet</servlet-name>
<servlet-class>servlet.CartServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>CartServlet</servlet-name>
<url-pattern>/servlet/CartServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%@ page import="entity.Cart" %>
<%@ page import="entity.Items" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'cart.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link type="text/css" rel="stylesheet" href="css/style1.css" />
<script language="javascript">
function delcfm() {
if (!confirm("確認要刪除？")) {
window.event.returnValue = false;
}
}
</script>
</head>
<body>
<h1>我的購物車</h1>
<a href="index.jsp">首頁</a> >> <a href="index.jsp">商品列表</a>
<hr>
<div id="shopping">
<form action="" method="">
<table>
<tr>
<th>商品名稱</th>
<th>商品單價</th>
<th>商品價格</th>
<th>購買數量</th>
<th>操作</th>
</tr>
<%
//首先判斷session中是否有購物車對象
if(request.getSession().getAttribute("cart")!=null)
{
%>
<!-- 循環的開始 -->
<%
Cart cart = (Cart)request.getSession().getAttribute("cart");
HashMap<Items,Integer> goods = cart.getGoods();
Set<Items> items = goods.keySet();
Iterator<Items> it = items.iterator();
while(it.hasNext())
{
Items i = it.next();
%>
<tr name="products" id="product_id_1">
<td class="thumb"><img src="images/<%=i.getPicture()%>" /><a href=""><%=i.getName()%></a></td>
<td class="number"><%=i.getPrice() %></td>
<td class="price" id="price_id_1">
<span><%=i.getPrice()*goods.get(i) %></span>
<input type="hidden" value="" />
</td>
<td class="number">
<%=goods.get(i)%>
</td>
<td class="delete">
<a href="servlet/CartServlet?action=delete&id=<%=i.getId()%>" onclick="delcfm();">刪除</a>
</td>
</tr>
<%
}
%>
<!--循環的結束-->
</table>
<div class="total"><span id="total">總計：<%=cart.getTotalPrice() %>￥</span></div>
<%
}
%>
<div class="button"><input type="submit" value="" /></div>
</form>
</div>
</body>
</html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %>
<%@ page import="entity.Items"%>
<%@ page import="dao.ItemsDAO"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'details.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link href="css/main.css" rel="stylesheet" type="text/css">
<script type="text/javascript" src="js/lhgcore.js"></script>
<script type="text/javascript" src="js/lhgdialog.js"></script>
<script type="text/javascript">
function selflog_show(id)
{
var num = document.getElementById("number").value;
J.dialog.get({id: 'haoyue_creat',title: '購物成功',width: 600,height:400, link: '<%=path%>/servlet/CartServlet?id='+id+'&num='+num+'&action=add', cover:true});
}
function add()
{
var num = parseInt(document.getElementById("number").value);
if(num<100)
{
document.getElementById("number").value = ++num;
}
}
function sub()
{
var num = parseInt(document.getElementById("number").value);
if(num>1)
{
document.getElementById("number").value = --num;
}
}
</script>
<style type="text/css">
hr{
border-color:FF7F00;
}
div{
float:left;
margin-left: 30px;
margin-right:30px;
margin-top: 5px;
margin-bottom: 5px;
}
div dd{
margin:0px;
font-size:10pt;
}
div dd.dd_name
{
color:blue;
}
div dd.dd_city
{
color:#000;
}
div #cart
{
margin:0px auto;
text-align:right;
}
span{
padding:0 2px;border:1px #c0c0c0 solid;cursor:pointer;
}
a{
text-decoration: none;
}
</style>
</head>
<body>
<h1>商品詳情</h1>
<a href="index.jsp">首頁</a> >> <a href="index.jsp">商品列表</a>
<hr>
<center>
<table width="750" height="60" cellpadding="0" cellspacing="0" border="0">
<tr>
<!-- 商品詳情 -->
<%
ItemsDAO itemDao = new ItemsDAO();
Items item = itemDao.getItemsById(Integer.parseInt(request.getParameter("id")));
if(item!=null)
{
%>
<td width="70%" valign="top">
<table>
<tr>
<td rowspan="5"><img src="images/<%=item.getPicture()%>" width="200" height="160"/></td>
</tr>
<tr>
<td><B><%=item.getName() %></B></td>
</tr>
<tr>
<td>產地：<%=item.getCity()%></td>
</tr>
<tr>
<td>價格：<%=item.getPrice() %>￥</td>
</tr>
<tr>
<td>購買數量：<span id="sub" onclick="sub();">-</span><input type="text" id="number" name="number" value="1" size="2"/><span id="add" onclick="add();">+</span></td>
</tr>
</table>
<div id="cart">
<img src="images/buy_now.png"><a href="javascript:selflog_show(<%=item.getId()%>)"><img src="images/in_cart.png"></a><a href="servlet/CartServlet?action=show"><img src="images/view_cart.jpg"/></a>
</div>
</td>
<%
}
%>
<%
String list ="";
//從客戶端獲得Cookies集合
Cookie[] cookies = request.getCookies();
//遍歷這個Cookies集合
if(cookies!=null&&cookies.length>0)
{
for(Cookie c:cookies)
{
if(c.getName().equals("ListViewCookie"))
{
list = c.getValue();
}
}
}
list+=request.getParameter("id")+",";
//如果瀏覽記錄超過1000條，清零.
String[] arr = list.split(",");
if(arr!=null&&arr.length>0)
{
if(arr.length>=1000)
{
list="";
}
}
Cookie cookie = new Cookie("ListViewCookie",list);
response.addCookie(cookie);
%>
<!-- 瀏覽過的商品 -->
<td width="30%" bgcolor="#EEE" align="center">
<br>
<b><font color="#FF7F00">您瀏覽過的商品</font></b><br>
<!-- 循環開始 -->
<%
ArrayList<Items> itemlist = itemDao.getViewList(list);
if(itemlist!=null&&itemlist.size()>0 )
{
System.out.println("itemlist.size="+itemlist.size());
for(Items i:itemlist)
{
%>
<div>
<dl>
<dt>
<a href="details.jsp?id=<%=i.getId()%>"><img src="images/<%=i.getPicture() %>" width="120" height="90" border="1"/></a>
</dt>
<dd class="dd_name"><%=i.getName() %></dd>
<dd class="dd_city">產地:<%=i.getCity() %> 價格:<%=i.getPrice() %> ￥ </dd>
</dl>
</div>
<%
}
}
%>
<!-- 循環結束 -->
</td>
</tr>
</table>
</center>
</body>
</html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'success.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<center>
<img src="images/add_cart_failure.jpg"/>
<hr>
<br>
<br>
<br>
</center>
</body>
</html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%@ page import="entity.Items"%>
<%@ page import="dao.ItemsDAO"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<style type="text/css">
hr{
border-color:FF7F00;
}
div{
float:left;
margin: 10px;
}
div dd{
margin:0px;
font-size:10pt;
}
div dd.dd_name
{
color:blue;
}
div dd.dd_city
{
color:#000;
}
</style>
</head>
<body>
<h1>商品展示</h1>
<hr>
<center>
<table width="750" height="60" cellpadding="0" cellspacing="0" border="0">
<tr>
<td>
<!-- 商品循環開始 -->
<%
ItemsDAO itemsDao = new ItemsDAO();
ArrayList<Items> list = itemsDao.getAllItems();
if(list!=null&&list.size()>0)
{
for(int i=0;i<list.size();i++)
{
Items item = list.get(i);
%>
<div>
<dl>
<dt>
<a href="details.jsp?id=<%=item.getId()%>"><img src="images/<%=item.getPicture()%>" width="120" height="90" border="1"/></a>
</dt>
<dd class="dd_name"><%=item.getName() %></dd>
<dd class="dd_city">產地:<%=item.getCity() %> 價格:￥ <%=item.getPrice() %></dd>
</dl>
</div>
<!-- 商品循環結束 -->
<%
}
}
%>
</td>
</tr>
</table>
</center>
</body>
</html><%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'success.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<center>
<img src="images/add_cart_success.jpg"/>
<hr>
<%
String id = request.getParameter("id");
String num = request.getParameter("num");
%>
您成功購買了<%=num%>件商品編號爲<%=id%>的商品
<br>
<br>
<br>
</center>
</body>
</html>2-13 練習題
MVC模型包含模型層、視圖層和控制器層，在下列組件中扮演控制器角色的是
Servlet
使用MVC模型搭建某網上書店系統設計用戶登陸界面，如果你是設計人員你將在MVC模型結構的( )中實現
視圖層
視圖層關注界面設計。