[TOC] ## 步驟 1 : 先運行，看到效果，再學習 先將完整的 tmall_ssm 項目（向老師要相關資料），配置運行起來，確認可用之后，再學習做了哪些步驟以達到這樣的效果。 ## 步驟 2 : 模仿和排錯 在確保可運行項目能夠正確無誤地運行之后，再嚴格照著教程的步驟，對代碼模仿一遍。 模仿過程難免代碼有出入，導致無法得到期望的運行結果，此時此刻通過比較**正確答案** ( 可運行項目 ) 和自己的代碼，來定位問題所在。 采用這種方式，**學習有效果，排錯有效率**，可以較為明顯地提升學習速度，跨過學習路上的各個檻。 ## 步驟 3 :購物車頁面操作 購物車頁面和服務端的交互主要是三個 1. 增加、減少某種產品的數量 2. 刪除某種產品 3. 選中產品后，提交到結算頁面  ## 步驟 4 : 調整訂單數量 點擊增加或者減少按鈕后，根據 **cartPage.jsp** 中的js代碼，會通過Ajax訪問`/forechangeOrderItem`路徑，導致``ForeController.changeOrderItem()``方法被調用 1. 判斷用戶是否登錄 2. 獲取pid和number 3. 遍歷出用戶當前所有的未生成訂單的OrderItem 4. 根據pid找到匹配的OrderItem，并修改數量后更新到數據庫 5. 返回字符串"success"  cartPage.jsp： ~~~ // 根據商品數量，商品價格，同步小計價格，接著調用calcCartSumPriceAndNumber()函數同步商品總數和總價格 function syncPrice(pid, num, price) { // 設定pid對應該商品購買數量 $(".orderItemNumberSetting[pid=" + pid + "]").val(num); // 根據商品數量，商品價格，同步小計價格 var cartProductItemSmallSumPrice = formatMoney(num * price); // 設定小計價格 $(".cartProductItemSmallSumPrice[pid=" + pid + "]").html("￥" + cartProductItemSmallSumPrice); // 重新計算上下總價格，總數量 calcCartSumPriceAndNumber(); var page = "forechangeOrderItem"; $.post(page, { "pid" : pid, "number" : num }, function(result) { if ("success" != result) { location.href = "login.jsp"; } }); } ~~~ ForeController： ~~~ package com.dodoke.tmall.controller; import java.util.ArrayList; import java.util.Collections; import java.util.List; import javax.servlet.http.HttpSession; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.util.HtmlUtils; import com.dodoke.tmall.comparator.ProductAllComparator; import com.dodoke.tmall.comparator.ProductDateComparator; import com.dodoke.tmall.comparator.ProductPriceComparator; import com.dodoke.tmall.comparator.ProductReviewComparator; import com.dodoke.tmall.comparator.ProductSaleCountComparator; import com.dodoke.tmall.pojo.Category; import com.dodoke.tmall.pojo.OrderItem; import com.dodoke.tmall.pojo.Product; import com.dodoke.tmall.pojo.ProductImage; import com.dodoke.tmall.pojo.PropertyValue; import com.dodoke.tmall.pojo.Review; import com.dodoke.tmall.pojo.User; import com.dodoke.tmall.service.CategoryService; import com.dodoke.tmall.service.OrderItemService; import com.dodoke.tmall.service.OrderService; import com.dodoke.tmall.service.ProductImageService; import com.dodoke.tmall.service.ProductService; import com.dodoke.tmall.service.PropertyValueService; import com.dodoke.tmall.service.ReviewService; import com.dodoke.tmall.service.UserService; import com.github.pagehelper.PageHelper; @Controller @RequestMapping("") public class ForeController { @Autowired CategoryService categoryService; @Autowired ProductService productService; @Autowired UserService userService; @Autowired ProductImageService productImageService; @Autowired PropertyValueService propertyValueService; @Autowired OrderService orderService; @Autowired OrderItemService orderItemService; @Autowired ReviewService reviewService; @RequestMapping("forehome") public String home(Model model) { List<Category> cs = categoryService.list(); productService.fill(cs); productService.fillByRow(cs); model.addAttribute("cs", cs); return "fore/home"; } @RequestMapping("foreregister") public String register(Model model, User user) { String name = user.getName(); // 把賬號里的特殊符號進行轉義 name = HtmlUtils.htmlEscape(name); user.setName(name); boolean exist = userService.isExist(name); if (exist) { String m = "用戶名已經被使用,不能使用"; model.addAttribute("msg", m); model.addAttribute("user", null); return "fore/register"; } userService.add(user); return "redirect:registerSuccessPage"; } @RequestMapping("forelogin") public String login(@RequestParam("name") String name, @RequestParam("password") String password, Model model, HttpSession session) { name = HtmlUtils.htmlEscape(name); User user = userService.get(name, password); if (null == user) { model.addAttribute("msg", "賬號密碼錯誤"); return "fore/login"; } session.setAttribute("user", user); return "redirect:forehome"; } @RequestMapping("forelogout") public String logout(HttpSession session) { session.removeAttribute("user"); return "redirect:forehome"; } @RequestMapping("foreproduct") public String product(int pid, Model model) { Product p = productService.get(pid); // 根據對象p，獲取這個產品對應的單個圖片集合 List<ProductImage> productSingleImages = productImageService.list(p.getId(), ProductImageService.type_single); // 根據對象p，獲取這個產品對應的詳情圖片集合 List<ProductImage> productDetailImages = productImageService.list(p.getId(), ProductImageService.type_detail); p.setProductSingleImages(productSingleImages); p.setProductDetailImages(productDetailImages); // 獲取產品的所有屬性值 List<PropertyValue> pvs = propertyValueService.list(p.getId()); // 獲取產品對應的所有的評價 List<Review> reviews = reviewService.list(p.getId()); // 設置產品的銷量和評價數量 productService.setSaleAndReviewNumber(p); model.addAttribute("reviews", reviews); model.addAttribute("p", p); model.addAttribute("pvs", pvs); return "fore/product"; } @RequestMapping("forecheckLogin") @ResponseBody public String checkLogin(HttpSession session) { User user = (User) session.getAttribute("user"); if (null != user) { return "success"; } return "fail"; } @RequestMapping("foreloginAjax") @ResponseBody public String loginAjax(@RequestParam("name") String name, @RequestParam("password") String password, HttpSession session) { name = HtmlUtils.htmlEscape(name); User user = userService.get(name, password); if (null == user) { return "fail"; } session.setAttribute("user", user); return "success"; } @RequestMapping("forecategory") public String category(int cid, String sort, Model model) { Category c = categoryService.get(cid); productService.fill(c); productService.setSaleAndReviewNumber(c.getProducts()); if (null != sort) { switch (sort) { case "review": Collections.sort(c.getProducts(), new ProductReviewComparator()); break; case "date": Collections.sort(c.getProducts(), new ProductDateComparator()); break; case "saleCount": Collections.sort(c.getProducts(), new ProductSaleCountComparator()); break; case "price": Collections.sort(c.getProducts(), new ProductPriceComparator()); break; case "all": Collections.sort(c.getProducts(), new ProductAllComparator()); break; } } model.addAttribute("c", c); return "fore/category"; } @RequestMapping("foresearch") public String search(String keyword, Model model) { PageHelper.offsetPage(0, 20); List<Product> ps = productService.search(keyword); productService.setSaleAndReviewNumber(ps); model.addAttribute("ps", ps); return "fore/searchResult"; } @RequestMapping("forebuyone") public String buyone(int pid, int num, HttpSession session) { Product p = productService.get(pid); int oiid = 0; User user = (User) session.getAttribute("user"); boolean found = false; List<OrderItem> ois = orderItemService.listByUser(user.getId()); for (OrderItem oi : ois) { if (oi.getProduct().getId().intValue() == p.getId().intValue()) { oi.setNumber(oi.getNumber() + num); orderItemService.update(oi); found = true; oiid = oi.getId(); break; } } if (!found) { OrderItem oi = new OrderItem(); oi.setUserId(user.getId()); oi.setNumber(num); oi.setProductId(pid); orderItemService.add(oi); oiid = oi.getId(); } return "redirect:forebuy?oiid=" + oiid; } @RequestMapping("forebuy") public String buy(Model model, String[] oiid, HttpSession session) { List<OrderItem> ois = new ArrayList<>(); float total = 0; for (String strid : oiid) { int id = Integer.parseInt(strid); OrderItem oi = orderItemService.get(id); total += oi.getProduct().getPromotePrice() * oi.getNumber(); ois.add(oi); } session.setAttribute("ois", ois); model.addAttribute("total", total); return "fore/buy"; } @RequestMapping("foreaddCart") @ResponseBody public String addCart(int pid, int num, Model model, HttpSession session) { Product p = productService.get(pid); User user = (User) session.getAttribute("user"); boolean found = false; List<OrderItem> ois = orderItemService.listByUser(user.getId()); for (OrderItem oi : ois) { if (oi.getProduct().getId().intValue() == p.getId().intValue()) { oi.setNumber(oi.getNumber() + num); orderItemService.update(oi); found = true; break; } } if (!found) { OrderItem oi = new OrderItem(); oi.setUserId(user.getId()); oi.setNumber(num); oi.setProductId(pid); orderItemService.add(oi); } return "success"; } @RequestMapping("forecart") public String cart(Model model, HttpSession session) { User user = (User) session.getAttribute("user"); List<OrderItem> ois = orderItemService.listByUser(user.getId()); model.addAttribute("ois", ois); return "fore/cart"; } @RequestMapping("forechangeOrderItem") @ResponseBody public String changeOrderItem(Model model, HttpSession session, int pid, int number) { User user = (User) session.getAttribute("user"); if (null == user) { return "fail"; } List<OrderItem> ois = orderItemService.listByUser(user.getId()); for (OrderItem oi : ois) { if (oi.getProduct().getId().intValue() == pid) { oi.setNumber(number); orderItemService.update(oi); break; } } return "success"; } } ~~~ ## 步驟 5 : 刪除訂單項 點擊刪除按鈕后，根據 cartPage.jsp 中的js代碼，會通過Ajax訪問/foredeleteOrderItem路徑，導致ForeController.deleteOrderItem方法被調用 1. 判斷用戶是否登錄 2. 獲取oiid 3. 刪除oiid對應的OrderItem數據 4. 返回字符串"success"  ~~~ // 點擊刪除鏈接，顯示模態框 $("a.deleteOrderItem").click(function() { deleteOrderItem = false; var oiid = $(this).attr("oiid") deleteOrderItemid = oiid; $("#deleteConfirmModal").modal('show'); }); // 點擊模態框中確認按鈕，隱藏模態框 $("button.deleteConfirmButton").click(function() { deleteOrderItem = true; $("#deleteConfirmModal").modal('hide'); }); // hidden.bs.modal的意思就是當彈出的模態框消失的時候，接下來回調的函數 $('#deleteConfirmModal').on('hidden.bs.modal', function(e) { if (deleteOrderItem) { var page = "foredeleteOrderItem"; // 根據訂單項id,刪除訂單項 $.post(page, { "oiid" : deleteOrderItemid }, function(result) { if ("success" == result) { $("tr.cartProductItemTR[oiid=" + deleteOrderItemid + "]").remove(); calcCartSumPriceAndNumber(); } else { location.href = "loginPage"; } }); } }); ~~~ ## 步驟 6 : 提交到結算頁面 在選中了購物車中的任意商品之后，結算按鈕呈現可點擊狀態。 點擊之后，提交到**結算頁面**，并帶上(多個)被選中的OrderItem對象的id 之后的流程就進入了前面講解過的**結算頁面**，在此不作贅述。