利用session来模拟购物网站的购物车，这次没有用静态页面，全部用Servlet来模拟。
用户点击购买之后，就会将商品加入到购物车中(其实就是放入session中)，等用户点

击结账的时候，就会将购物车中的信息全部给用户看。

欢迎界面，里面有"购买"、"结账"链接，点击购买，就会加入"洗衣机"这个商品。然后
点击"结账"就会看到你买的商品
WelcomeServlet:

package cn.edu.session;


import java.io.IOException;
import java.io.PrintWriter;


import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


public class WelcomeServlet extends HttpServlet {


	public void doGet(HttpServletRequest request, HttpServletResponse 


response)
			throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out=response.getWriter();
        //进主页的session会用到最后
        request.getSession();
        
        String url1=response.encodeURL("/day07/SessionDemo1");/*这个方法会自
动的在URL上面加上session的id号,这是防止用户禁用cookie(原因看我以前的文章)*/
        String url2=response.encodeURL("/day07/SessionDemo2");
        //效果：<a href='/day07/SessionDemo1;jsessionid=572FCD20D16825556EAAD9E8B1D3984D'>购买</a></br>
        //<a href='/day07/SessionDemo2;jsessionid=572FCD20D16825556EAAD9E8B1D3984D'>结账</a>
        
        out.write("<a href='"+url1+"'>购买</a></br>");
        out.write("<a href='"+url2+"'>结账</a>");
	}


	public void doPost(HttpServletRequest request, HttpServletResponse 


response)
			throws ServletException, IOException {
		doGet(request,response);
	}


}

购买Servlet，会将购买的商品信息存入session
package cn.edu.session;
SessionDemo1:

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;


//购买
public class SessionDemo1 extends HttpServlet {


	public void doGet(HttpServletRequest request, HttpServletResponse 


response)
			throws ServletException, IOException {
        HttpSession session=request.getSession();
        //request.getSession(false)只获取session，不出创建session（一般显示


购物车的时候会出现此代码）
        
        String sessionid=session.getId();//详见sessio的id
        Cookie cookie=new Cookie("JSESSIONID",sessionid);
        cookie.setPath("/day07");
        cookie.setMaxAge(30*60);
        response.addCookie(cookie);
        session.setAttribute("name", "洗衣机");
	}


	public void doPost(HttpServletRequest request, HttpServletResponse 


response)
			throws ServletException, IOException {
		doGet(request,response);
	}


}

结账Servlet，会将session中存入的商品信息拿出来

SessionDemo2:

package cn.edu.session;


import java.io.IOException;
import java.io.PrintWriter;


import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;


//结账
public class SessionDemo2 extends HttpServlet {


	public 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();
        String product=(String)session.getAttribute("name");
        out.write("您购买的商品是"+product);
	}


	public void doPost(HttpServletRequest request, HttpServletResponse 


response)
			throws ServletException, IOException {
		doGet(request,response);
	}


}

模拟了购买一个商品进购物车的场景。后面还有一个模拟购物车的项目，是自选商品进购物车，比这更完善一些：http://blog.csdn.net/acmman/article/details/43451029。

转载请注明出处:http://blog.csdn.net/acmman