基于JAVA EE技术，采用MVC模式SSM框架开发一个销售管理系统。

package com.dgut.sms.controller; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.validation.Valid; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.validation.BindingResult; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.ModelAttribute; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import com.dgut.sms.bean.Bill; import com.dgut.sms.bean.BillSearchCondition; import com.dgut.sms.bean.Contract; import com.dgut.sms.bean.Product; import com.dgut.sms.bean.Purchase; import com.dgut.sms.dao.PurchaseDao; import com.dgut.sms.service.BillService; import com.dgut.sms.service.ContractService; import com.dgut.sms.service.ProductService; @RequestMapping("bill") @Controller public class BillController { @Autowired public BillService service; @Autowired public ProductService productService; @Autowired public ContractService contractService; @Autowired public PurchaseDao purchaseDao; private Double beforePrice; @GetMapping("/billManagerList") public String billManagerList(Model model) { List<Bill> bills = service.getAllBill(); model.addAttribute("bills", bills); model.addAttribute("condition", new BillSearchCondition()); return "bill/salesManagerBillList"; } @GetMapping("/billEdit/{id}") public String billEdit(@PathVariable("id") Integer id, Model model) { Bill bill = service.getBillByBillId(id); String busyMessage = service.lockBillByBillId(id); //判断该订单是否被操作中 if(busyMessage.equals("该订单正在被操作，请稍后再试!")) { model.addAttribute("busyMessage",busyMessage); List<Bill> bills = service.getAllBill(); model.addAttribute("bills", bills); model.addAttribute("condition", new BillSearchCondition()); return "bill/salesManagerBillList"; } beforePrice = bill.getTotalPrice(); //获取修改前订单的价格 List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); model.addAttribute("bill", bill); return "bill/billEdit"; } @ModelAttribute //准备模型数据 public void prepareModelAttribute(@RequestParam(value="billId", required=false) Integer id, HttpServletRequest request, Model model) { String servletPath = request.getServletPath(); if(servletPath.equals("/contract/updateContract")) { //为/update请求准备模型数据 Bill bill = service.getBillByBillId(id); model.addAttribute("bill", bill); } } @PostMapping("/updateBill") public String updateBill(@Valid Bill bill, BindingResult result, Model model) { if(result.hasErrors()) { return "bill/billEdit"; } else { String message; if(productService.getProductById(bill.getProductId())==null) { model.addAttribute("BillProductNotExist", "商品不存在!"); List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); return "bill/billEdit"; } if(productService.getProductById(bill.getProductId()).getSell().equals("否")) { String unSellMessage = "商品已下架，无法更新订单!"; List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); model.addAttribute("message", unSellMessage); return "bill/billEdit"; } try { service.updateBill(bill); service.unlockBillByBillId(bill.getBillId()); } catch (Exception e) { message = "商品数量不足!"; List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); model.addAttribute("message", message); return "bill/billEdit"; } if(service.getBillByBillId(bill.getBillId()).getPerform().equals("未发货")) { Contract contract = contractService.getContractByContractId(bill.getContractId()); Double price = service.getBillByBillId(bill.getBillId()).getPrice() * service.getBillByBillId(bill.getBillId()).getQuantity(); contractService.addPriceByContractId(contract.getContractId(), price); //添加修改后订单的价格 contractService.reducePriceByContractId(contract.getContractId(), beforePrice); //减去修改前订单的价格 return "redirect:/bill/billManagerList"; } else { List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); model.addAttribute("message", "商品已发货,无法修改!"); return "bill/billEdit"; } } } @GetMapping("/billDelete/{id}") public String billDelete(@PathVariable("id") Integer id) { Contract contract = contractService.getContractByContractId(service.getBillByBillId(id).getContractId()); Integer contractId = contract.getContractId(); Double price = service.getBillByBillId(id).getPrice() * service.getBillByBillId(id).getQuantity(); contractService.reducePriceByContractId(contractId, price); service.deleteBillById(id); return "redirect:/bill/billManagerList"; } @GetMapping("/addEdit") public String addEdit(Model model) { model.addAttribute("bill", new Bill()); List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); return "bill/addEdit"; } @PostMapping("add") public String add(@Valid Bill bill, BindingResult result, Model model) { if(result.hasErrors()) { return "bill/addEdit"; } else { if(contractService.getContractByContractId(bill.getContractId()).getPerform().equals("已履行")) { List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); model.addAttribute("message", "合同已履行，无法添加发货单！"); return "bill/addEdit"; } if(productService.getProductById(bill.getProductId())==null) { model.addAttribute("BillProductNotExist", "商品不存在!"); List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); return "bill/addEdit"; } if(productService.getProductById(bill.getProductId()).getSell().equals("否")) { String unSellMessage = "商品已下架，无法创建订单!"; model.addAttribute("message", unSellMessage); List<Product> products = productService.getAllProduct(); List<Contract> contracts = contractService.getAllContract(); model.addAttribute("contracts", contracts); model.addAttribute("products", products); return "bill/addEdit"; } bill.setPerform("未发货"); bill.setPrice(productService.getPriceByProductId(bill.getProductId())); bill.setTotalPrice(productService.getPriceByProductId(bill.getProductId())*bill.getQuantity()); try { service.addBill(bill); contractService.addPriceByContractId(bill.getContractId(), bill.getTotalPrice());