web实验报告——会话跟踪使用程序

来源：互联网发布：拳击书知乎编辑：程序博客网时间：2024/05/21 16:22

实验八会话跟踪实用程序

一、实验目的

通过实验掌握下列知识：

1、理解动态网页中会话跟踪的实现基础；

2、能使用会话跟踪实现购物车程序。

二、实验内容及步骤

1、购物车程序基础练习

1）将书中购物车程序实例源代码，配置于tomcat服务器中；

2）运行该程序，查看运行效果，并将运行流程与效果，记录在实验报告中；

分析该程序采取的线程安全措施，并记录在实验报告中。

购物车程序实例源代码：session.rar

运行界面：

TechBooksPage：

OrderPage：

ShowSession：

2、购物车程序改进练习

1）为书中的基础程序增加登录页面（login.jsp），并增加登录判断页面（LoginCheck.java）,若用户名为bookstore，密码为123456，则登录成功，直接跳转显示KidsBooksPage，否则返回登录页面重新登录；

2）若登录成功，则在登录判断页面（LoginCheck.java）中增加代码：
session.setAttribute(“loginUser”, true); 用以标志登录用户；

3）购书页面（KidsBooksPage、TechBooksPage）与订单页面（OrderPage）必须要登录用户才能访问，未登录用户需跳转到登录页面进行登录；

4）若登录用户再次访问登录页面（login.jsp），则无须再次登录，直接跳转显示KidsBooksPage。

源代码：

<%@ page language="java" contentType="text/html; charset=gb2312"

pageEncoding="gb2312"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>用户登录界面</title>

</head>

<body>

//使用内置对象request获取loginUser的session的值，若为空则停留在登陆界面，

//若存在session值就直接跳转到KidsBooksPage页面

Boolean flag1;

HttpSession loginSession = request.getSession();

flag1 = (Boolean)loginSession.getAttribute("loginUser");

if(flag1==null || flag1==false)

{%>

<br>

</div>

<tr>

</tr>

<tr>

</tr>

<tr>

</tr>

</table>

</form>

<%}

else

{%>

<jsp:forward page= "KidsBooksPage" />

<% }

</body>

</html>

LoginCheck.java

package session;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.Cookie;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

/**

*ServletimplementationclassLoginCheck

publicclass LoginCheck extends HttpServlet {

privatestaticfinallongserialVersionUID = 1L;

/**

*@seeHttpServlet#HttpServlet()

public LoginCheck() {

super();

// TODO Auto-generated constructor stub

}

/**

*@seeHttpServlet#doGet(HttpServletRequestrequest,HttpServletResponseresponse)

protectedvoid doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// TODO Auto-generated method stub

HttpSession session = request.getSession();

String name = request.getParameter("userName");

String pwd = request.getParameter("userPwd");

if(name.equals("bookstore") && pwd.equals("123456"))

{

session.setAttribute("loginUser", true);

response.sendRedirect("KidsBooksPage");

}

else

{

response.sendRedirect("login.jsp");

}

/**

*@seeHttpServlet#doPost(HttpServletRequestrequest,HttpServletResponseresponse)

protectedvoid doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// TODO Auto-generated method stub

}

运行结果：

3、购物车程序改进练习2（选做）

1）为以上程序增加注销功能，在购书页面（KidsBooksPage、TechBooksPage）与订单页面（OrderPage）中增加注销按钮；

2）按下注销按钮后，交由Logout.java页面进行处理：
session.invalidate();
response.sendRedirect(“../login.jsp”);

源代码：

package session;

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import java.util.*;

publicabstractclass CatalogPage extends HttpServlet {

private Item[] items;

private String[] itemIDs;

private String title;

/**GivenanarrayofitemIDs,lookthemupinthe

* CatalogandputtheircorrespondingItementry

* intotheitemsarray.TheItemcontainsashort

* description,alongdescription,andaprice,

* usingtheitemIDastheuniquekey.

* <P>

* ServletsthatextendCatalogPage<B>must</B>call

* thismethod(usuallyfrominit)beforetheservlet

* isaccessed.

protectedvoid setItems(String[] itemIDs) {

this.itemIDs = itemIDs;

items = new Item[itemIDs.length];

for(int i=0; i<items.length; i++) {

items[i] = Catalog.getItem(itemIDs[i]);

}

/**Setsthepagetitle,whichisdisplayedin

* anH1headinginresultantpage.

* <P>

* ServletsthatextendCatalogPage<B>must</B>call

* thismethod(usuallyfrominit)beforetheservlet

* isaccessed.

protectedvoid setTitle(String title) {

this.title = title;

}

/**Firstdisplaytitle,then,foreachcatalogitem,

* putitsshortdescriptioninalevel-two(H2)heading

* withthepriceinparenthesesandlongdescription

* below.Beloweachentry,putanorderbutton

* thatsubmitsinfototheOrderPageservletfor

* theassociatedcatalogentry.

* <P>

* ToseetheHTMLthatresultsfromthismethod,do

* "ViewSource"onKidsBooksPageorTechBooksPage,two

* concreteclassesthatextendthisabstractclass.

publicvoid doGet(HttpServletRequest request,

HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("text/html");

response.setCharacterEncoding("gb2312");

//获取名为loginUser的session，若为true,就显示该页面，否则返回login.jsp页面

Boolean flag;

HttpSession session = request.getSession();

synchronized(session) {

flag = (Boolean)session.getAttribute("loginUser");

if(flag==null || flag == false)

{

response.sendRedirect("login.jsp");

}

else

{

if (items == null) {

response.sendError(response.SC_NOT_FOUND,

"Missing Items.");

return;

}

PrintWriter out = response.getWriter();

out.println(ServletUtilities.headWithTitle(title) +

"<BODY BGCOLOR=/"#FDF5E6/">/n" +

"<H1 ALIGN=/"CENTER/">" + title + "</H1>");

Item item;

for(int i=0; i<items.length; i++) {

out.println("<HR>");

item = items[i];

// Show error message if subclass lists item ID

// that's not in the catalog.

if (item == null) {

out.println("<FONT COLOR=/"RED/">" +

"Unknown item ID " + itemIDs[i] +

"</FONT>");

} else {

out.println();

String formURL =

"OrderPage";

// Pass URLs that reference own site through encodeURL.

formURL = response.encodeURL(formURL);

out.println

("<FORM ACTION=/"" + formURL + "/">/n" +

"<INPUT TYPE=/"HIDDEN/" NAME=/"itemID/" " +

" VALUE=/"" + item.getItemID() + "/">/n" +

"<H2>" + item.getShortDescription() +

" ($" + item.getCost() + ")</H2>/n" +

item.getLongDescription() + "/n" +

"<P>/n<CENTER>/n" +

"<INPUT TYPE=/"SUBMIT/" " +

"VALUE=/"Add to Shopping Cart/">/n" +

"</CENTER>/n<P>/n</FORM>");

String formURL2 = "Logout";

formURL2 = response.encodeURL(formURL2);

out.println("<FORM ACTION=/"" + formURL2 + "/">/n" +

"<INPUT TYPE=/"SUBMIT/" " +

"VALUE=/"注销/">/n" +

"</CENTER>/n<P>/n</FORM>"

);

}

out.println("<HR>/n</BODY></HTML>");

}

/**POSTandGETrequestshandledidentically.*/

publicvoid doPost(HttpServletRequest request,

HttpServletResponse response)

throws ServletException, IOException {

doGet(request, response);

}