基于cookie显示用户浏览记录

package cn.ishuai.cookie; import java.io.IOException; import java.io.PrintWriter; import java.util.HashMap; import java.util.Map; 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 cn.ishuai.cookie.DBOS; public class CookieDemo extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); String username=request.getParameter("username"); String password=request.getParameter("pwd"); Map<String,BookInfo> books =DBOS.getAllInfo(); if("admin".equals(username)&&"123".equals(password)){ out.write("欢迎来到图书网站<br/>"); for (Map.Entry<String, BookInfo> book : books.entrySet()) { //target=_blank是在新窗口中打开；？id是给目标页传参用的；共有四本书，点击哪个就传哪本书的id out.write("<a href='"+request.getContextPath()+"/servlet/doDemo?id="+book.getKey()+"' target='_blank'>"+book.getValue().getName()+"</a><br/>"); } } out.write("<hr/>历史浏览记录<br/>"); //从客户端cookie中读取当前都浏览了哪些书 Cookie[] ck= request.getCookies(); for(int i=0;ck!=null && i<ck.length;i++){ System.out.println(ck[i].getName()); if("1".equals(ck[i].getName())){ out.write(ck[i].getValue()+"<br/>"); } if("2".equals(ck[i].getName())){ out.write(ck[i].getValue()+"<br/>"); } if("3".equals(ck[i].getName())){ out.write(ck[i].getValue()); //System.out.println(ck[i].getName()); } if("4".equals(ck[i].getName())){ out.write(ck[i].getValue()+"<br/>"); } } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }