Java Web开发之基于Session的购物商店实现方法

本文实例讲述了Java Web开发之基于Session的购物商店实现方法。分享给大家供大家参考，具体如下：

package cn.com.shopping;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
//完成购买
public class BuyServlet extends HttpServlet {
 private static final long serialVersionUID = 1L;
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
   String id=request.getParameter("id");
   Book book=(Book)Db.getAll().get(id);
   //再加上那个关闭Cookie时session的剞劂方案
   //阻止session的时候解决方案
   HttpSession session=request.getSession(false);
   //从session中得到用户的保存所有书的集合（购物车）
   List list=(List)session.getAttribute("list");
   if(list==null)
   {
     list=new ArrayList();
     session.setAttribute("list", list);
   }
   list.add(book);
   String url=response.encodeRedirectURL("/Session/SessionCountDemo");
   response.sendRedirect(url);
 }
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
   doGet(request,response);
 }
}
package cn.com.shopping;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
//显示书
public class ListBookServlet extends HttpServlet {
 private static final long serialVersionUID = 1L;
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
   response.setCharacterEncoding("UTF-8");
   response.setContentType("text/html;charset=UTF-8");
   PrintWriter out=response.getWriter();
   HttpSession session=request.getSession();
   out.print("本店有如下的商品：<br/>");
   Map<String ,Book > map=Db.getAll();
   for(Map.Entry<String, Book> entry:map.entrySet())
   {
     Book book=entry.getValue();
     String url=response.encodeURL("/Session/BuyServlet?id="+book.getId());
     out.print(book.getName()+"<a href='"+url+"' target='_blank' >购买</a><br/>");
   }
 }
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
   doGet(request,response);
 }
}
//Db作为数据库
class Db
{
 private static Map<String ,Book> map=new LinkedHashMap();
 static
 {
   map.put("1", new Book("1","Java WEB开发","WY","好书"));
   map.put("2", new Book("2","WEB开发","zt","一般"));
   map.put("3", new Book("3","程序设计","df","较好书"));
   map.put("4", new Book("4","计算机组成","as","一般好书"));
   map.put("5", new Book("5","编译原理","ty","很好书"));
   map.put("6", new Book("6","网络维护","hj","非常好书"));
 }
 public static Map getAll()
 {
   return map;
 }
}
//书
class Book
{
 private String id;
 private String name;
 private String author;
 private String description;
 public Book() {
   super();
   // TODO Auto-generated constructor stub
 }
 public Book(String id, String name, String author, String description) {
   super();
   this.id = id;
   this.name = name;
   this.author = author;
   this.description = description;
 }
 public String getId() {
   return id;
 }
 public void setId(String id) {
   this.id = id;
 }
 public String getName() {
   return name;
 }
 public void setName(String name) {
   this.name = name;
 }
 public String getAuthor() {
   return author;
 }
 public void setAuthor(String author) {
   this.author = author;
 }
 public String getDescription() {
   return description;
 }
 public void setDescription(String description) {
   this.description = description;
 }
}
package cn.com.shopping;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class SessionCountDemo extends HttpServlet {
 private static final long serialVersionUID = 1L;
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
   response.setCharacterEncoding("UTF-8");
   response.setContentType("text/html;charset=UTF-8");
   PrintWriter out=response.getWriter();
   HttpSession session=request.getSession();
   if(session==null)
   {
     out.write("您没买任何的商品！");
     return;
   }
   out.write("您购买了如下的商品：");
   List<Book> list=(List) session.getAttribute("list");
   for(Book book:list)
   {
     out.write(book.getName());
   }
 }
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
   doGet(request,response);
 }
}

希望本文所述对大家Java web程序设计有所帮助。