案例24-商品瀏覽歷史記錄
阿新 • • 發佈：2018-02-12
ges nts info 獲取 html 商品 initial ram parameter
1 案例效果
2 案例分析
3 web層部分
1 ProductInfoServlet 代碼修改
package www.test.web.servlet; import java.io.IOException; import java.sql.SQLException; import java.util.Arrays; import java.util.LinkedList; import java.util.List; 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 www.test.domain.Product; import www.test.service.ProductService; public class ProductInfoServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throwsServletException, IOException { //獲取cid和當前頁 String cid = request.getParameter("cid"); String currentPage = request.getParameter("currentPage"); //獲取pid String pid =request.getParameter("pid"); //傳遞給service層並調取service層的方法 ProductService service = newProductService(); Product product = null; try { product = service.findProductByPid(pid); } catch (SQLException e) { e.printStackTrace(); } //存儲到request域中 request.setAttribute("product", product); request.setAttribute("cid", cid); request.setAttribute("currentPage", currentPage); //獲取客戶端攜帶的cookie----獲得名字是pids的cookie String pids = pid; Cookie[] cookies = request.getCookies(); if(cookies!=null){ for(Cookie cookie:cookies){ if("pids".equals(cookie.getName())){ pids = cookie.getValue(); //1-3-2 本次訪問的商品的pid是8----->8-1-3-2 //1-3-2 本次訪問的商品的pid是3----->3-1-2 //1-3-2 本次訪問的商品的pid是1----->2-1-3 //將pids拆成一個數組 String[] split = pids.split("-");//{3,1,2} //數組轉換成集合 List<String> asList = Arrays.asList(split);//[3,1,2] LinkedList<String> list = new LinkedList<String>(asList); //[3,1,2] //判斷集合中是否存在當前的pid /*if(list.contains(pid)){ //包含當前查看的商品的pid //先刪掉然後放在頭上 list.remove(pid); list.addFirst(pid); }else{ //不包含當前查看的商品的pid 直接將該pid放在頭上 list.addFirst(pid); }*/ //上面代碼的優化 //不管包不包含都需要放到頭上 if(list.contains(pid)){ //包含當前查看的商品的pid list.remove(pid); } list.addFirst(pid); //將[3,1,2]轉成3-1-2字符串 StringBuffer sb = new StringBuffer(); for(int i=0;i<list.size()&&i<7;++i){ //&&i<7 頁面最多顯示7個瀏覽商品的歷史記錄 sb.append(list.get(i)); sb.append("-"); //3-1-2- } //去掉3-1-2-後面的- //substring包含頭不包含尾 pids = sb.substring(0, sb.length()-1); } } } //創建cookie回寫 Cookie cookie_pids = new Cookie("pids", pids); cookie_pids.setMaxAge(60*60); //單位為秒 設置cookie的存儲事件一個小時 //設置cookie的攜帶路徑 cookie_pids.setPath(request.getContextPath()); //將cookie_pids寫回去 response.addCookie(cookie_pids); //轉發 request.getRequestDispatcher("/product_info.jsp").forward(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
2 ProductListByCidServlet 代碼修改
package www.test.web.servlet; import java.io.IOException; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; 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 www.test.domain.Product; import www.test.service.ProductService; import www.test.vo.PageBean; public class ProductListByCidServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //獲取cid String cid = request.getParameter("cid"); String currentPageStr = request.getParameter("currentPage"); if(currentPageStr == null){ currentPageStr = "1"; } int currentPage = Integer.parseInt(currentPageStr); int currentCount =12; //根據cid查詢商品 ProductService service = new ProductService(); PageBean<Product> pageBean = service.findProductListByCid(cid,currentPage,currentCount); request.setAttribute("pageBean", pageBean); request.setAttribute("cid", cid); //定義一個集合記錄歷史商品信息的集合 List<Product> historyProductList = new ArrayList<Product>(); //獲取客戶端攜帶的名字叫pids的cookie Cookie[] cookies = request.getCookies(); if(cookies!=null){ for (Cookie cookie : cookies) { if("pids".equals(cookie.getName())){ String pids = cookie.getValue(); //3-1-2 String[] split = pids.split("-"); for(String pid:split){ Product product =null; try { product = service.findProductByPid(pid); historyProductList.add(product); } catch (SQLException e) { e.printStackTrace(); } } } } } //將歷史記錄的集合放到域中 request.setAttribute("historyProductList", historyProductList); //轉發 request.getRequestDispatcher("/product_list.jsp").forward(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
4 WebContent部分
1 product_list.jsp代碼修改
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!DOCTYPE html> <html> <head> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>會員登錄</title> <link rel="stylesheet" href="css/bootstrap.min.css" type="text/css" /> <script src="js/jquery-1.11.3.min.js" type="text/javascript"></script> <script src="js/bootstrap.min.js" type="text/javascript"></script> <!-- 引入自定義css文件 style.css --> <link rel="stylesheet" href="css/style.css" type="text/css" /> <style> body { margin-top: 20px; margin: 0 auto; width: 100%; } .carousel-inner .item img { width: 100%; height: 300px; } </style> </head> <body> <!-- 引入header.jsp --> <jsp:include page="/header.jsp"></jsp:include> <div class="row" style="width: 1210px; margin: 0 auto;"> <div class="col-md-12"> <ol class="breadcrumb"> <li><a href="#">首頁</a></li> </ol> </div> <c:forEach items="${pageBean.list }" var="product"> <div class="col-md-2" style="height: 250px"> <a href="${pageContext.request.contextPath }/productInfo?pid=${product.pid}&cid=${cid}¤tPage=${pageBean.currentPage}"> <img src="${pageContext.request.contextPath }/${product.pimage}" width="170" height="170" style="display: inline-block;"> </a> <p> <a href="${pageContext.request.contextPath }/productInfo?pid=${product.pid}&cid=${cid}¤tPage=${pageBean.currentPage}" style=‘color: green‘>${product.pname }</a> </p> <p> <font color="#FF0000">商城價：¥${product.shop_price }</font> </p> </div> </c:forEach> </div> <!--分頁 --> <div style="width: 380px; margin: 0 auto; margin-top: 50px;"> <ul class="pagination" style="text-align: center; margin-top: 10px;"> <!-- 2 上一頁 --> <!--判斷當前頁是否是第一頁 --> <c:if test="${pageBean.currentPage==1 }"> <li class="disabled"> <a href="javascript:void(0);" aria-label="Previous"> <span aria-hidden="true">«</span> </a> </li> </c:if> <c:if test="${pageBean.currentPage!=1 }"> <li> <a href="${pageContext.request.contextPath }/productListByCid?cid=${cid}¤tPage=${pageBean.currentPage-1 }" aria-label="Previous"> <span aria-hidden="true">«</span> </a> </li> </c:if> <!-- 1 顯示每一頁 --> <c:forEach begin="1" end="${pageBean.totalPage }" var="page"> <!-- 判斷是否是當前頁 --> <c:if test="${page==pageBean.currentPage }"> <li class="active"><a href="javascript:void(0);">${page }</a></li> </c:if> <c:if test="${page!=pageBean.currentPage }"> <li><a href="${pageContext.request.contextPath }/productListByCid?cid=${cid}¤tPage=${page }">${page }</a></li> </c:if> </c:forEach> <!-- 3 下一頁 --> <!--判斷當前頁是否是第一頁 --> <c:if test="${pageBean.currentPage==pageBean.totalPage }"> <li class="disabled"> <a href="javascript:void(0);" aria-label="Next"> <span aria-hidden="true">»</span> </a> </li> </c:if> <c:if test="${pageBean.currentPage!=pageBean.totalPage }"> <li> <a href="${pageContext.request.contextPath }/productListByCid?cid=${cid}¤tPage=${pageBean.currentPage+1 }" aria-label="Next"> <span aria-hidden="true">»</span> </a> </li> </c:if> </ul> </div> <!-- 分頁結束 --> <!--商品瀏覽記錄--> <div style="width: 1210px; margin: 0 auto; padding: 0 9px; border: 1px solid #ddd; border-top: 2px solid #999; height: 246px;"> <h4 style="width: 50%; float: left; font: 14px/30px 微軟雅黑">瀏覽記錄</h4> <div style="width: 50%; float: right; text-align: right;"> <a href="">more</a> </div> <div style="clear: both;"></div> <div style="overflow: hidden;"> <ul style="list-style: none;"> <c:forEach items="${historyProductList }" var="historyPro"> <li style="width: 150px; height: 216; float: left; margin: 0 8px 0 0; padding: 0 18px 15px; text-align: center;"> <img src="${pageContext.request.contextPath }/${historyPro.pimage}" width="130px" height="130px" /> </li> </c:forEach> </ul> </div> </div> <!-- 引入footer.jsp --> <jsp:include page="/footer.jsp"></jsp:include> </body> </html>
案例24-商品瀏覽歷史記錄