第1章 Servlet基础
1-1 Servlet概述
Servlet基础
- 什么是Servlet
- Tomcat容器等级
- 手工编写第一个Servlet
- 使用MyEclipse编写Servlet
- Servlet声明周期
- Servlet获取九大内置对象
- Servlet与表单
- Servlet路径跳转
- 阶段项目
什么是Servlet 先有JSP还是先有Servlet？
我可以负责任的告诉大家先有Servlet。没错，Jsp的前身就是Servlet。
Servlet是在服务端运行的小程序。一个Servlet就是一个Java类，并且
可以通过“请求-响应”编程模型来访问的这个驻留在服务器内里的Servlet
程序。
1-2 Tomcat容器等级
Tomcat容器等级
Tomcat的容器分为四个等级，Servlet的容器管理Context容器，一个
Context对应一个Web工程。
Tomcat->Container容器->Engine->HOST->Servlet容器->Context
1-3 手工编写第一个Servlet
手工编写第一个Servlet
- 继承HttpServlet
- 重写doGet()或者doPost()方法
- 在web.xml中注册Servlet
Servlet ->三个方法Init() service() destory()
|
GenericServlet(Abstract Class) ->与协议无关的Servlet
|
HttpServlet(Abstract Class) ->实现了http协议的servlet
|
自定义Servlet ->一般重写（覆盖）doGet()，doPost()方法
public class HelloServlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest requset, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("处理Get()请求...");
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("处理Post()请求...");
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>第一个Servlet小例子</h1>
<hr>
<a href="servlet/HelloServlet">Get方式请求HelloServlet</a><br>
<form action="servlet/HelloServlet" method="post">
<input type="submit" value="Post方式请求HelloServlet"/>
</form>
</body>
</html>1-4 使用MyEclipse编写Servlet
使用M有Eclipse编写第一个Servlet
- src->new->Servlet
- 重写doGet()或者doPost()
- 部署运行
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("处理get请求...");
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("处理post请求...");
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>第一个Servlet小例子</h1>
<hr>
<a href="servlet/HelloServlet">Get方式请求HelloServlet</a><br>
<form action="servlet/HelloServlet" method="post">
<input type="submit" value="Post方式请求HelloServlet"/>
</form>
</body>
</html>
1-5 练习题
假设在helloapp应用中有一个HelloServlet类，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> 那么在浏览器端访问HelloServlet的URL是什么?
http://localhost:8080/helloapp/hello
localhost是服务器主机名，也可以是IP地址127.0.0.1；8080是tomcat服务器的端口号；helloapp是web工程的上下文地址ContexRoot（一般情况下与web工程名一致）；最后是标签中的内容。
1-6 Servlet执行流程和生命周期
- servlet执行流程
- 使用MyEclipse编写第一个Servlet
Get方式请求HelloServlet -> Get方式请求HelloServlet
/servlet/HelloServlet
servlet.HelloServlet
public class HelloServlet extends HttpServlet{
@Override
protected void doGet(HttpServletRequest requset, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("处理Get()请求...");Servlet生命周期
- 舒适化阶段，调用init()方法
- 响应客户端请求阶段，调用service()方法。由service()方法根据提交
方式选择执行doGet()或者doPost()方法。 - 终止阶段，调用destroy()方法。
1-7 练习题
在Java EE中Servlet是在服务器端运行以处理客户端请求而做出的响应的程序。下列选项中属于Servlet生命周期阶段的是
加载和实例化、初始化、服务和销毁
1-8 练习题
编写Servlet的doPost方法时，需要抛出异常为
ServletException， IOException
1-9 Tomcat装载Servlet的三种情况
在下列时刻Servlet容器装载Servlet
- Servlet容器启动时刻自动装载某些Servlet，实现它只需在web.xml文件中的
之间添加如下代码：1
数字越小表示优先级别越高。 - 在Servlet容器启动后，客户端首次向Servlet发送请求。
- Servlet类文件被更新后，重新装载Servlet。
public class TestServlet1 extends HttpServlet {
/**
* Constructor of the object.
*/
public TestServlet1() {
System.out.println("TestServlet1构造方法被执行....");
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
System.out.println("TestServlet1销毁方法被执行....");
}
/**
* 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()方法被执行...");
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()方法被执行...");
doGet(request,response); //让doPost()执行与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的初始化方法被执行....");
}
}public class TestServlet2 extends HttpServlet {
/**
* Constructor of the object.
*/
public TestServlet2() {
System.out.println("TestServlet2构造方法被执行....");
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
System.out.println("TestServlet2销毁方法被执行....");
}
/**
* 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()方法被执行...");
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()方法被执行...");
doGet(request,response); //让doPost()执行与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的初始化方法被执行....");
}
}<?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生命周期</h1>
<hr>
<a href="servlet/TestServlet1">以Get方式请求TestServlet1</a>
</body>
</html>
1-10 Servlet与JSP内置对象的对应关系
| JSP对象 | 怎么获得 |
|---|---|
| out | resp.getWriter |
| request | service方法中req参数 |
| response | service方法中resp参数 |
| session | req.getSession()函数 |
| application | getServletContext()函数 |
| exception | Throwable |
| page | this |
| pageContext | PageContext |
| Config | getServletConfig函数 |
1-11 Servlet获取表单数据
//用户实体类
public class Users {
private String username; //用户名
private String mypassword; //密码
private String email; //电子邮箱
private String gender; //性别
private Date birthday; //出生日期
private String[] favorites; //爱好
private String introduce; //自我介绍
private boolean flag; //是否接受协议
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";
}
//用来获取多个复选按钮的值
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);
//把注册成功的用户对象保存在session中
request.getSession().setAttribute("regUser", u);
//跳转到注册成功页面
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>用户注册</h1>
<hr>
<form name="regForm" action="servlet/RegServlet" method="post" >
<table border="0" width="800" cellspacing="0" cellpadding="0">
<tr>
<td class="lalel">用户名：</td>
<td class="controler"><input type="text" name="username" /></td>
</tr>
<tr>
<td class="label">密码：</td>
<td class="controler"><input type="password" name="mypassword" ></td>
</tr>
<tr>
<td class="label">确认密码：</td>
<td class="controler"><input type="password" name="confirmpass" ></td>
</tr>
<tr>
<td class="label">电子邮箱：</td>
<td class="controler"><input type="text" name="email" ></td>
</tr>
<tr>
<td class="label">性别：</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">爱好：</td>
<td class="controler">
<input type="checkbox" name="favorite" value="nba"> NBA
<input type="checkbox" name="favorite" value="music"> 音乐
<input type="checkbox" name="favorite" value="movie"> 电影
<input type="checkbox" name="favorite" value="internet"> 上网
</td>
</tr>
<tr>
<td class="label">自我介绍：</td>
<td class="controler">
<textarea name="introduce" rows="10" cols="40"></textarea>
</td>
</tr>
<tr>
<td class="label">接受协议：</td>
<td class="controler">
<input type="checkbox" name="isAccept" value="true">是否接受霸王条款
</td>
</tr>
<tr>
<td colspan="2" align="center">
<input type="submit" value="注册"/>
<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>用户信息</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">用户名：</td>
<td class="content"> <jsp:getProperty name="regUser" property="username"/></td>
</tr>
<tr>
<td class="title">密码：</td>
<td class="content"> <jsp:getProperty name="regUser" property="mypassword"/></td>
</tr>
<tr>
<td class="title">性别：</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">爱好：</td>
<td class="content">
<%
String[] favorites = regUser.getFavorites();
for(String f:favorites)
{
%>
<%=f%>
<%
}
%>
</td>
</tr>
<tr>
<td class="title">自我介绍：</td>
<td class="content"> <jsp:getProperty name="regUser" property="introduce"/></td>
</tr>
<tr>
<td class="title">是否介绍协议：</td>
<td class="content"> <jsp:getProperty name="regUser" property="flag"/></td>
</tr>
</table>
</center>
</body>
</html>1-12 练习题
在J2EE中,对于HttpServlet类的描述,不正确的是
我们自己编写的Servlet继承了HttpServlet类,一般只需覆盖doPost或者doGet方法,不必覆盖service( )方法,因为一个sevrvice( )方法是空的。
HttpServlet类扩展了GenericServlet类,实现了GenericServlet类的抽象方法
sevrvice( )
HttpServlet类有两个sevrvice( )方法
我们自己编写的Servlet继承了HttpServlet类,一般只需覆盖doPost或者doGet方法,不必覆盖sevrvice( )方法.因为一个sevrvice( )方法会调用doPost或者doGet方法
该选项描述错误，不覆盖service()方法，不是因为该方法是空，而是因为sevrvice( )方法会调用doPost或者doGet方法。
1-13 Servlet路径跳转
Servlet路径跳转
- 绝对路径：放之四海而皆准的路径
- 相对路径：相对于当前资源的路径
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 {
//请求重定向方式跳转到test.jsp,当前路径是ServletPathDirection/servlet/
//response.sendRedirect("test.jsp");
//使用request.getContextPath获得上下文对象
//response.sendRedirect(request.getContextPath()+"/test.jsp");
//服务器内部跳转,这里的斜线表示项目的根目录
//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处必须以/开头，这里的/表示项目的根目录 -->
<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路径跳转</h1>
<hr>
<!--使用相对路径访问HelloServlet -->
<!-- /servlet/HelloServlet 第一个/表示服务器的根目录 -->
<a href="servlet/HelloServlet">访问HelloServlet!</a><br>
<!-- 使用绝对路径 访问HelloServlet,可以使用path变量:path变量表示项目的根目录-->
<a href="<%=path%>/servlet/HelloServlet">访问HelloServlet!</a><br>
<!--表单中action的URL地址写法，与超链接方式完全相同。 -->
<a href="servlet/TestServlet">访问TestServlet,跳转到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 阶段案例
//用户类
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);
//判断用户名和密码是否合法
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">
登录失败！请检查用户或者密码!<br>
<a href="login.jsp">返回登录</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();
}
%>
欢迎您<font color="red"><%=loginUser%></font>,登录成功！
</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>用户名: </label>
<input name="username" value="" />
<label>密码: </label>
<input type="password" name="password" value="">
</p>
<p class="space">
<input type="submit" value="登录" class="login" style="cursor: pointer;"/>
</p>
</form>
</div>
</div>
</body>
</html>第2章 应用MVC架构实现项目
2-1 获取初始化参数
Servlet高级
- 获取初始化参数
- MVC设计模式
- Model2简介
- 阶段项目
获取初始化参数
在web.xml中配置Servlet时，可以配置一些初始化参数。而在Servlet中可以
通过ServletConfig接口提供的方法来获取这些参数。
public class GetInitParameterServlet extends HttpServlet {
private String username;//用户名
private String password; //密码
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>"+"用户名："+this.getUsername()+"</h2>");
out.println("<h2>"+"密码："+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>获取初始化参数演示案例</h1>
<hr>
<a href="servlet/GetInitParameterServlet">获取初始化参数Servlet</a>
</body>
</html>2-2 练习题
从以下哪一个选项中可以获得Servlet的初始化参数
ServletConfig
2-3 MVC模型介绍
MVC
MVC模式：MVC（Model、View、Controller），是软件开发过程中比较流行的
设计思想。旨在分离模型、控制、视图。是一种分层思想的体现。
2-4 Model2模型介绍
Model1简介
浏览器 - JSP JavaBean - 企业数据库
Model2简介
JSP(V)-Servlet(C)-JavaBean(M)-DB
2-5 项目概述
使用servlet技术实现购物车效果
2-6 界面原型效果及界面开发步骤
MVC模型实现（Jsp+Servlet+dao）
创建购物车类
编写Servlet
创建页面层
2-7 购物车类的设计
购物车类(Cart)的设计
- 添加
- 删除
- 计算总金额
//购物车类
public class Cart {
//购买商品的集合
private HashMap<Items,Integer> goods;
//购物车的总金额
private double totalPrice;
//构造方法
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;
}
//添加商品进购物车
public boolean addGoodsInCart(Items item,int number){
goods.put(item, number);
calTotalPrice();//重新计算购物车的总金额
return true;
}
//删除商品的方法
public boolean removeGoodsFromCart(Items item){
goods.remove(item);
calTotalPrice();//重新计算购物车的总金额
return true;
}
//统计购物车的总金额
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);//设置购物车的总金额
return sum;
}
}2-8 测试购物车类
//购物车类
public class Cart {
// 购买商品的集合
private HashMap<Items, Integer> goods;
// 购物车的总金额
private double totalPrice;
// 构造方法
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;
}
// 添加商品进购物车
public boolean addGoodsInCart(Items item, int number) {
goods.put(item, number);
calTotalPrice();// 重新计算购物车的总金额
return true;
}
// 删除商品的方法
public boolean removeGoodsFromCart(Items item) {
goods.remove(item);
calTotalPrice();// 重新计算购物车的总金额
return true;
}
// 统计购物车的总金额
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);// 设置购物车的总金额
return sum;
}
public static void main(String[] args) {
// 先创建两个商品对象
Items i1 = new Items(1, "沃特篮球鞋", "温州", 200, 500, "001.jpg");
Items i2 = new Items(2, "李宁运动鞋", "广州", 300, 500, "002.jpg");
Items i3 = new Items(1, "沃特篮球鞋", "温州", 200, 500, "001.jpg");
Cart c = new Cart();
c.addGoodsInCart(i1, 1);
c.addGoodsInCart(i2, 2);
// 再次购买沃特篮球鞋，购买3双
c.addGoodsInCart(i3, 3);
// 变量购物商品的集合
Set<Map.Entry<Items, Integer>> items = c.getGoods().entrySet();
for (Map.Entry<Items, Integer> obj : items) {
System.out.println(obj);
}
System.out.println("购物车的总金额：" + c.getTotalPrice());
}
}2-9 如何保证不添加重复商品进购物车
//购物车类
public class Cart {
//购买商品的集合
private HashMap<Items,Integer> goods;
//购物车的总金额
private double totalPrice;
//构造方法
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;
}
//添加商品进购物车的方法
public boolean addGoodsInCart(Items item ,int number)
{
if(goods.containsKey(item))
{
goods.put(item, goods.get(item)+number);
}
else
{
goods.put(item, number);
}
calTotalPrice(); //重新计算购物车的总金额
return true;
}
//删除商品的方法
public boolean removeGoodsFromCart(Items item)
{
goods.remove(item);
calTotalPrice(); //重新计算购物车的总金额
return true;
}
//统计购物车的总金额
public double calTotalPrice()
{
double sum = 0.0;
Set<Items> keys = goods.keySet(); //获得键的集合
Iterator<Items> it = keys.iterator(); //获得迭代器对象
while(it.hasNext())
{
Items i = it.next();
sum += i.getPrice()* goods.get(i);
}
this.setTotalPrice(sum); //设置购物车的总金额
return this.getTotalPrice();
}
public static void main(String[] args) {
//先创建两个商品对象
Items i1 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg");
Items i2 = new Items(2,"李宁运动鞋","广州",300,500,"002.jpg");
Items i3 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg");
Cart c = new Cart();
c.addGoodsInCart(i1, 1);
c.addGoodsInCart(i2, 2);
//再次购买沃特篮球鞋，购买3双
c.addGoodsInCart(i3, 3);
//变量购物商品的集合
Set<Map.Entry<Items, Integer>> items= c.getGoods().entrySet();
for(Map.Entry<Items, Integer> obj:items)
{
System.out.println(obj);
}
System.out.println("购物车的总金额："+c.getTotalPrice());
}
}//商品类
public class Items {
private int id; // 商品编号
private String name; // 商品名称
private String city; // 产地
private int price; // 价格
private int number; // 库存
private String picture; // 商品图片
//保留此不带参数的构造方法
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 "商品编号："+this.getId()+",商品名称："+this.getName();
}
}2-10 添加商品进购物车
2-11 显示购物车
2-12 商品删除
//商品的业务逻辑类
public class ItemsDAO {
// 获得所有的商品信息
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语句
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);// 把一个商品加入集合
}
return list; // 返回集合。
} catch (Exception ex) {
ex.printStackTrace();
return null;
} finally {
// 释放数据集对象
if (rs != null) {
try {
rs.close();
rs = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
// 释放语句对象
if (stmt != null) {
try {
stmt.close();
stmt = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
}
// 根据商品编号获得商品资料
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语句
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 {
// 释放数据集对象
if (rs != null) {
try {
rs.close();
rs = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
// 释放语句对象
if (stmt != null) {
try {
stmt.close();
stmt = null;
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
}
//获取最近浏览的前五条商品信息
public ArrayList<Items> getViewList(String list)
{
System.out.println("list:"+list);
ArrayList<Items> itemlist = new ArrayList<Items>();
int iCount=5; //每次返回前五条记录
if(list!=null&&list.length()>0)
{
String[] arr = list.split(",");
System.out.println("arr.length="+arr.length);
//如果商品记录大于等于5条
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;
}
}
}//购物车类
public class Cart {
//购买商品的集合
private HashMap<Items,Integer> goods;
//购物车的总金额
private double totalPrice;
//构造方法
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;
}
//添加商品进购物车的方法
public boolean addGoodsInCart(Items item ,int number)
{
if(goods.containsKey(item))
{
goods.put(item, goods.get(item)+number);
}
else
{
goods.put(item, number);
}
calTotalPrice(); //重新计算购物车的总金额
return true;
}
//删除商品的方法
public boolean removeGoodsFromCart(Items item)
{
goods.remove(item);
calTotalPrice(); //重新计算购物车的总金额
return true;
}
//统计购物车的总金额
public double calTotalPrice()
{
double sum = 0.0;
Set<Items> keys = goods.keySet(); //获得键的集合
Iterator<Items> it = keys.iterator(); //获得迭代器对象
while(it.hasNext())
{
Items i = it.next();
sum += i.getPrice()* goods.get(i);
}
this.setTotalPrice(sum); //设置购物车的总金额
return this.getTotalPrice();
}
public static void main(String[] args) {
//先创建两个商品对象
Items i1 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg");
Items i2 = new Items(2,"李宁运动鞋","广州",300,500,"002.jpg");
Items i3 = new Items(1,"沃特篮球鞋","温州",200,500,"001.jpg");
Cart c = new Cart();
c.addGoodsInCart(i1, 1);
c.addGoodsInCart(i2, 2);
//再次购买沃特篮球鞋，购买3双
c.addGoodsInCart(i3, 3);
//变量购物商品的集合
Set<Map.Entry<Items, Integer>> items= c.getGoods().entrySet();
for(Map.Entry<Items, Integer> obj:items)
{
System.out.println(obj);
}
System.out.println("购物车的总金额："+c.getTotalPrice());
}
}//商品类
public class Items {
private int id; // 商品编号
private String name; // 商品名称
private String city; // 产地
private int price; // 价格
private int number; // 库存
private String picture; // 商品图片
//保留此不带参数的构造方法
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 "商品编号："+this.getId()+",商品名称："+this.getName();
}
}public class CartServlet extends HttpServlet {
private String action ; //表示购物车的动作 ,add,show,delete
//商品业务逻辑类的对象
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")) //如果是添加商品进购物车
{
if(addToCart(request,response))
{
request.getRequestDispatcher("/success.jsp").forward(request, response);
}
else
{
request.getRequestDispatcher("/failure.jsp").forward(request, response);
}
}
if(action.equals("show"))//如果是显示购物车
{
request.getRequestDispatcher("/cart.jsp").forward(request, response);
}
if(action.equals("delete")) //如果是执行删除购物车中的商品
{
if(deleteFromCart(request,response))
{
request.getRequestDispatcher("/cart.jsp").forward(request, response);
}
else
{
request.getRequestDispatcher("/cart.jsp").forward(request, response);
}
}
}
}
//添加商品进购物车的方法
private boolean addToCart(HttpServletRequest request, HttpServletResponse response)
{
String id = request.getParameter("id");
String number = request.getParameter("num");
Items item = idao.getItemsById(Integer.parseInt(id));
//是否是第一次给购物车添加商品,需要给session中创建一个新的购物车对象
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;
}
}
//从购物车中删除商品
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"; //数据库驱动
//连接数据库的URL地址
private static final String url="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8";
private static final String username="root";//数据库的用户名
private static final String password="root";//数据库的密码
private static Connection conn=null;
//静态代码块负责加载驱动
static
{
try
{
Class.forName(driver);
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
//单例模式返回数据库连接对象
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("数据库连接正常！");
}
else
{
System.out.println("数据库连接异常！");
}
}
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("确认要删除？")) {
window.event.returnValue = false;
}
}
</script>
</head>
<body>
<h1>我的购物车</h1>
<a href="index.jsp">首页</a> >> <a href="index.jsp">商品列表</a>
<hr>
<div id="shopping">
<form action="" method="">
<table>
<tr>
<th>商品名称</th>
<th>商品单价</th>
<th>商品价格</th>
<th>购买数量</th>
<th>操作</th>
</tr>
<%
//首先判断session中是否有购物车对象
if(request.getSession().getAttribute("cart")!=null)
{
%>
<!-- 循环的开始 -->
<%
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();">删除</a>
</td>
</tr>
<%
}
%>
<!--循环的结束-->
</table>
<div class="total"><span id="total">总计：<%=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: '购物成功',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>商品详情</h1>
<a href="index.jsp">首页</a> >> <a href="index.jsp">商品列表</a>
<hr>
<center>
<table width="750" height="60" cellpadding="0" cellspacing="0" border="0">
<tr>
<!-- 商品详情 -->
<%
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>产地：<%=item.getCity()%></td>
</tr>
<tr>
<td>价格：<%=item.getPrice() %>￥</td>
</tr>
<tr>
<td>购买数量：<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 ="";
//从客户端获得Cookies集合
Cookie[] cookies = request.getCookies();
//遍历这个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")+",";
//如果浏览记录超过1000条，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);
%>
<!-- 浏览过的商品 -->
<td width="30%" bgcolor="#EEE" align="center">
<br>
<b><font color="#FF7F00">您浏览过的商品</font></b><br>
<!-- 循环开始 -->
<%
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">产地:<%=i.getCity() %> 价格:<%=i.getPrice() %> ￥ </dd>
</dl>
</div>
<%
}
}
%>
<!-- 循环结束 -->
</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>
<!-- 商品循环开始 -->
<%
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">产地:<%=item.getCity() %> 价格:￥ <%=item.getPrice() %></dd>
</dl>
</div>
<!-- 商品循环结束 -->
<%
}
}
%>
</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");
%>
您成功购买了<%=num%>件商品编号为<%=id%>的商品
<br>
<br>
<br>
</center>
</body>
</html>2-13 练习题
MVC模型包含模型层、视图层和控制器层，在下列组件中扮演控制器角色的是
Servlet
使用MVC模型搭建某网上书店系统设计用户登陆界面，如果你是设计人员你将在MVC模型结构的( )中实现
视图层
视图层关注界面设计。