購物車操作
阿新 • • 發佈：2019-01-14
加入購物車
import java.io.IOException; import java.io.PrintWriter; import java.util.HashMap; import java.util.Map; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class Add2CartServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //設定編碼 response.setContentType("text/html;charset=utf-8"); PrintWriter writer = response.getWriter(); //獲取商品的名稱 String name=request.getParameter("name"); name=new String(name.getBytes("iso-8859-1"),"utf-8"); //將商品新增到購物車中 //從session中獲取購物車 Map<String,Integer> car=(Map<String, Integer>) request.getSession().getAttribute("cart"); Integer count=null; //判斷購物車是否為空 if(car==null){ //第一次購物 建立購物車 car=new HashMap<String, Integer>(); //將購物車放入session中 request.getSession().setAttribute("cart", car); count=1; }else{ //購物車不為空，繼續判斷購物車中是否有該商品 count=car.get(name); if(count==null){ //購物車沒有該商品 count=1; }else{ //購物車中有該商品 count++; } } //將商品放入到購物車中 car.put(name, count); writer.println("已經將<b>"+name+"</b>新增到購物車中<hr/>"); writer.print("<a href='/cookie/product_list.jsp'>繼續購物</a>"); writer.print("<a href='/cookie/cart.jsp'>檢視購物車</a>"); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } }
cart.jsp
<%@ page import="java.util.Map" %> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <table border="1" align="center" width="50%"> <tr> <td>商品名稱</td> <td>數量</td> </tr> <% //1.獲取購物車 Map<String,Integer> map = (Map<String,Integer>)session.getAttribute("cart"); //2.判斷購物車是否為空 if(map==null){ //2.1若為空 out.print("<tr><td colspan='2'>親，購物車空空，先逛逛</td></tr>"); }else{ //2.2若不為空 遍歷購物車 for(String name:map.keySet()){ out.print("<tr>"); out.print("<td>"); out.print(name); out.print("</td>"); out.print("<td>"); out.print(map.get(name)); out.print("</td>"); out.print("</tr>"); } } %> </table> <hr/> <center> <a href="/cookie/product_list.jsp">繼續購物</a> <a href="/cookie/clearcart">清空購物車</a> </center> </body> </html>
清空購物車
import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class ClearCartServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //清空session request.getSession().invalidate(); //重定向 response.sendRedirect(request.getContextPath()+"/cart.jsp"); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } }