简单的文件下载代码模板

前言：本案例下载的是.xlsx格式模板文件

模板文件位置

模板文件的样式

java代码

核心方法：exportBusinessReport()

package com.xxx.controller;

import com.alibaba.dubbo.config.annotation.Reference;
import com.xxx.constant.MessageConstant;
import com.xxx.entity.Result;
import com.xxx.service.MemberService;
import com.xxx.service.ReportService;
import com.xxx.service.SetmealService;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.*;

@RestController
@RequestMapping("/report")
public class ReportController {
    @Reference
    private MemberService memberService;

    @Reference
    private SetmealService setmealService;
    @Reference
    private ReportService reportService;

    // 导出运营数据报表
    @RequestMapping(value = "/exportBusinessReport")
    public Result exportBusinessReport(HttpServletRequest request, HttpServletResponse response){
        try {
            // 远程调用报表服务获取报表数据
            Map<String, Object> result  = reportService.getBusinessReportData();

            //取出返回结果数据，准备将报表数据写入到Excel文件中
            String reportDate = (String) result.get("reportDate");
            Integer todayNewMember = (Integer) result.get("todayNewMember");
            Integer totalMember = (Integer) result.get("totalMember");
            Integer thisWeekNewMember = (Integer) result.get("thisWeekNewMember");
            Integer thisMonthNewMember = (Integer) result.get("thisMonthNewMember");
            Integer todayOrderNumber = (Integer) result.get("todayOrderNumber");
            Integer thisWeekOrderNumber = (Integer) result.get("thisWeekOrderNumber");
            Integer thisMonthOrderNumber = (Integer) result.get("thisMonthOrderNumber");
            Integer todayVisitsNumber = (Integer) result.get("todayVisitsNumber");
            Integer thisWeekVisitsNumber = (Integer) result.get("thisWeekVisitsNumber");
            Integer thisMonthVisitsNumber = (Integer) result.get("thisMonthVisitsNumber");
            List<Map> hotSetmeal = (List<Map>) result.get("hotSetmeal");

            // 获得Excel模板文件绝对路径
            System.out.println("获取真实路径：" + request.getSession().getServletContext().getRealPath("template"));
            String temlateRealPath = request.getSession().getServletContext().getRealPath("template") + File.separator+"report_template.xlsx";

            //读取模板文件创建Excel表格对象
            XSSFWorkbook workbook = new XSSFWorkbook(new FileInputStream(new File(temlateRealPath)));
            XSSFSheet sheet = workbook.getSheetAt(0);

            XSSFRow row = sheet.getRow(2);
            row.getCell(5).setCellValue(reportDate);//日期

            row = sheet.getRow(4);
            row.getCell(5).setCellValue(todayNewMember);//新增会员数（本日）
            row.getCell(7).setCellValue(totalMember);//总会员数

            row = sheet.getRow(5);
            row.getCell(5).setCellValue(thisWeekNewMember);//本周新增会员数
            row.getCell(7).setCellValue(thisMonthNewMember);//本月新增会员数

            row = sheet.getRow(7);
            row.getCell(5).setCellValue(todayOrderNumber);//今日预约数
            row.getCell(7).setCellValue(todayVisitsNumber);//今日出游数

            row = sheet.getRow(8);
            row.getCell(5).setCellValue(thisWeekOrderNumber);//本周预约数
            row.getCell(7).setCellValue(thisWeekVisitsNumber);//本周出游数

            row = sheet.getRow(9);
            row.getCell(5).setCellValue(thisMonthOrderNumber);//本月预约数
            row.getCell(7).setCellValue(thisMonthVisitsNumber);//本月出游数

            int rowNum = 12;
            for(Map map : hotSetmeal){//热门套餐
                String name = (String) map.get("name");
                Long setmeal_count = (Long) map.get("setmeal_count");
                BigDecimal proportion = (BigDecimal) map.get("proportion");
                row = sheet.getRow(rowNum ++);
                row.getCell(4).setCellValue(name);//套餐名称
                row.getCell(5).setCellValue(setmeal_count);//预约数量
                row.getCell(6).setCellValue(proportion.doubleValue());//占比
            }

            // 通过输出流进行文件下载
            ServletOutputStream out = response.getOutputStream();
            // 下载的数据类型
            response.setContentType("application/vnd.ms-excel");
            // 设置下载形式
            response.setHeader("content-Disposition", "attachment;filename=report.xlsx");
            workbook.write(out);

            out.flush();
            out.close();
            workbook.close();

            return null;
        } catch (Exception e) {
            e.printStackTrace();
            return new Result(false, MessageConstant.GET_BUSINESS_REPORT_FAIL,null);
        }
    }

    // 运营数据统计
    @RequestMapping(value = "/getBusinessReportData")
    public Result getBusinessReportData(){
        try {
            Map<String,Object> map =  reportService.getBusinessReportData();
            // 成功
            return new Result(true, MessageConstant.GET_BUSINESS_REPORT_SUCCESS,map);
        } catch (Exception e) {
            e.printStackTrace();
            return new Result(false, MessageConstant.GET_BUSINESS_REPORT_FAIL);
        }
    }

    // 预约套餐人数
    @RequestMapping(value = "/getSetmealReport")
    public Result getSetmealReport(){
        // 获取预约套餐人数
       List<Map<String,Object>> list = setmealService.getSetmealReport();
       // 套餐名
        List<String> setmealNames = new ArrayList<>();

        for (Map<String, Object> setMealMap : list) {
            setmealNames.add((String) setMealMap.get("name"));
        }

        Map<String,Object> map = new HashMap<>();
        map.put("setmealCount",list);
        map.put("setmealNames",setmealNames);
        return new Result(true,MessageConstant.QUERY_SETMEALLIST_SUCCESS,map);
    }

    // 会员数量统计
    @RequestMapping(value = "/getMemberReport")
    public Result getMemberReport(){
        // ① 创建一个日历对象，根据这个日历对象获取所有的月份
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH,-12);
        List<String> months = new ArrayList<>();
        for (int i = 0; i < 12; i++) {
            calendar.add(Calendar.MONTH,1);
            months.add(new SimpleDateFormat("yyyy-MM").format(calendar.getTime()));
        }
        // ② 查询会员数量
       List<Integer> memberCount = memberService.findMemberCountByMonth(months);
        // ③ 创建一个 map ,存储 months 和 memberCount
        Map<String,Object> map = new HashMap<>();
        map.put("months",months);
        map.put("memberCount",memberCount);

        return new Result(true, MessageConstant.GET_MEMBER_NUMBER_REPORT_SUCCESS,map);
    }
}