$(".buyLink").click(function(){
        var url = "forecheckLogin";
        axios.get(url).then(function(response) {
        	if(0==response.data.code){
                 var pid = vue.p.id;
                 var num= $(".productNumberSetting").val();
	             var url =  "forebuyone?pid="+pid+"&num="+num;
	             axios.get(url).then(function(response) {
	             	var oiid = response.data;
	             	location.href="buy?oiid="+oiid;	
	             });	            		
			}
        	else{
                $("#loginModal").modal('show');                     
        	}
        });
        return false;
    });

package com.how2java.tmall.dao;

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;

import com.how2java.tmall.pojo.Order;
import com.how2java.tmall.pojo.OrderItem;
import com.how2java.tmall.pojo.Product;
import com.how2java.tmall.pojo.User;

public interface OrderItemDAO extends JpaRepository<OrderItem,Integer>{
	List<OrderItem> findByOrderOrderByIdDesc(Order order);
	List<OrderItem> findByProduct(Product product);
	List<OrderItem> findByUserAndOrderIsNull(User user);
}

package com.how2java.tmall.service;

import com.how2java.tmall.dao.OrderItemDAO;
import com.how2java.tmall.pojo.Order;
import com.how2java.tmall.pojo.OrderItem;
import com.how2java.tmall.pojo.Product;
import com.how2java.tmall.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class OrderItemService {
	@Autowired OrderItemDAO orderItemDAO;
	@Autowired ProductImageService productImageService;

	public void fill(List<Order> orders) {
		for (Order order : orders)
			fill(order);
	}
	public void update(OrderItem orderItem) {
		orderItemDAO.save(orderItem);
	}

	public void fill(Order order) {
		List<OrderItem> orderItems = listByOrder(order);
		float total = 0;
		int totalNumber = 0;
		for (OrderItem oi :orderItems) {
			total+=oi.getNumber()*oi.getProduct().getPromotePrice();
			totalNumber+=oi.getNumber();
			productImageService.setFirstProdutImage(oi.getProduct());
		}
		order.setTotal(total);
		order.setOrderItems(orderItems);
		order.setTotalNumber(totalNumber);
		order.setOrderItems(orderItems);
	}

	public void add(OrderItem orderItem) {
		orderItemDAO.save(orderItem);
	}
	public OrderItem get(int id) {
		return orderItemDAO.findOne(id);
	}

	public void delete(int id) {
		orderItemDAO.delete(id);
	}

	public int getSaleCount(Product product) {
		List<OrderItem> ois =listByProduct(product);
		int result =0;
		for (OrderItem oi : ois) {
			if(null!=oi.getOrder())
				if(null!= oi.getOrder() && null!=oi.getOrder().getPayDate())
					result+=oi.getNumber();
		}
		return result;
	}

	public List<OrderItem> listByProduct(Product product) {
		return orderItemDAO.findByProduct(product);
	}
	public List<OrderItem> listByOrder(Order order) {
		return orderItemDAO.findByOrderOrderByIdDesc(order);
	}

	public List<OrderItem> listByUser(User user) {
		return orderItemDAO.findByUserAndOrderIsNull(user);
	}
}

    @GetMapping("forebuyone")
    public Object buyone(int pid, int num, HttpSession session) {
        return buyoneAndAddCart(pid,num,session);
    }

    private int buyoneAndAddCart(int pid, int num, HttpSession session) {
        Product product = productService.get(pid);
        int oiid = 0;

        User user =(User)  session.getAttribute("user");
        boolean found = false;
        List<OrderItem> ois = orderItemService.listByUser(user);
        for (OrderItem oi : ois) {
            if(oi.getProduct().getId()==product.getId()){
                oi.setNumber(oi.getNumber()+num);
                orderItemService.update(oi);
                found = true;
                oiid = oi.getId();
                break;
            }
        }

        if(!found){
            OrderItem oi = new OrderItem();
            oi.setUser(user);
            oi.setProduct(product);
            oi.setNumber(num);
            orderItemService.add(oi);
            oiid = oi.getId();
        }
        return oiid;
    }

package com.how2java.tmall.web;

import com.how2java.tmall.comparator.*;
import com.how2java.tmall.pojo.*;
import com.how2java.tmall.service.*;
import com.how2java.tmall.util.Result;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.util.HtmlUtils;

import javax.servlet.http.HttpSession;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@RestController
public class ForeRESTController {
    @Autowired
    CategoryService categoryService;
    @Autowired
    ProductService productService;
    @Autowired
    UserService userService;
    @Autowired
    ProductImageService productImageService;
    @Autowired
    PropertyValueService propertyValueService;
    @Autowired
    OrderItemService orderItemService;
    @Autowired
    ReviewService reviewService;

    @GetMapping("/forehome")
    public Object home() {
        List<Category> cs= categoryService.list();
        productService.fill(cs);
        productService.fillByRow(cs);
        categoryService.removeCategoryFromProduct(cs);
        
        return cs;
    }    
    @PostMapping("/foreregister")
    public Object register(@RequestBody User user) {
        String name =  user.getName();
        String password = user.getPassword();
        name = HtmlUtils.htmlEscape(name);
        user.setName(name);
        boolean exist = userService.isExist(name);
            
        if(exist){
            String message ="用户名已经被使用,不能使用";
            return Result.fail(message);
        }
        
		user.setPassword(password);
		
        userService.add(user);
        
    	return Result.success();
    }

    @PostMapping("/forelogin")
    public Object login(@RequestBody User userParam, HttpSession session) {
        String name =  userParam.getName();
        name = HtmlUtils.htmlEscape(name);

        User user =userService.get(name,userParam.getPassword());
        if(null==user){
            String message ="账号密码错误";
            return Result.fail(message);
        }
        else{
            session.setAttribute("user", user);
            return Result.success();
        }
    }

    @GetMapping("/foreproduct/{pid}")
    public Object product(@PathVariable("pid") int pid) {
        Product product = productService.get(pid);

        List<ProductImage> productSingleImages = productImageService.listSingleProductImages(product);
        List<ProductImage> productDetailImages = productImageService.listDetailProductImages(product);
        product.setProductSingleImages(productSingleImages);
        product.setProductDetailImages(productDetailImages);

        List<PropertyValue> pvs = propertyValueService.list(product);
        List<Review> reviews = reviewService.list(product);
        productService.setSaleAndReviewNumber(product);
        productImageService.setFirstProdutImage(product);

        Map<String,Object> map= new HashMap<>();
        map.put("product", product);
        map.put("pvs", pvs);
        map.put("reviews", reviews);

        return Result.success(map);
    }

    @GetMapping("forecheckLogin")
    public Object checkLogin( HttpSession session) {
        User user =(User)  session.getAttribute("user");
        if(null!=user)
            return Result.success();
        return Result.fail("未登录");
    }
    @GetMapping("forecategory/{cid}")
    public Object category(@PathVariable int cid,String sort) {
        Category c = categoryService.get(cid);
        productService.fill(c);
        productService.setSaleAndReviewNumber(c.getProducts());
        categoryService.removeCategoryFromProduct(c);

        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;
            }
        }

        return c;
    }
    @PostMapping("foresearch")
    public Object search( String keyword){
        if(null==keyword)
            keyword = "";
        List<Product> ps= productService.search(keyword,0,20);
        productImageService.setFirstProdutImages(ps);
        productService.setSaleAndReviewNumber(ps);
        return ps;
    }

    @GetMapping("forebuyone")
    public Object buyone(int pid, int num, HttpSession session) {
        return buyoneAndAddCart(pid,num,session);
    }

    private int buyoneAndAddCart(int pid, int num, HttpSession session) {
        Product product = productService.get(pid);
        int oiid = 0;

        User user =(User)  session.getAttribute("user");
        boolean found = false;
        List<OrderItem> ois = orderItemService.listByUser(user);
        for (OrderItem oi : ois) {
            if(oi.getProduct().getId()==product.getId()){
                oi.setNumber(oi.getNumber()+num);
                orderItemService.update(oi);
                found = true;
                oiid = oi.getId();
                break;
            }
        }

        if(!found){
            OrderItem oi = new OrderItem();
            oi.setUser(user);
            oi.setProduct(product);
            oi.setNumber(num);
            orderItemService.add(oi);
            oiid = oi.getId();
        }
        return oiid;
    }

}