spring boot 将数据导出Excel 并实现下载功能

Controller层：

 @RequestMapping(value="/admin/download",produces = {"application/vnd.ms-excel;charset=UTF-8"})
    public ResponseEntity download(HttpSession session, HttpServletResponse response){

            List upList=competitionSignUpDao.findAll();
            for (int i=0;i> list=exportExcel.createExcelRecord(upList);
            String columnNames[]={"学号","姓名","性别","专业","班级","报名时间"};//列名
            String keys[]    =     {"studentNumber","studentName","studentSex","studentSpecialy","studentClass","time"};//map中的key
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            try {
                ExcelUtils.createWorkBook(list,keys,columnNames).write(os);
            } catch (IOException e) {
                e.printStackTrace();
            }
            byte[] content = os.toByteArray();
            HttpHeaders httpHeaders = new HttpHeaders();
            httpHeaders.add("Content-Disposition", "attachment;filename="+ new String((fileName + ".xlsx").getBytes()));
            ResponseEntity responseEntity = new ResponseEntity(content,httpHeaders,HttpStatus.OK);
        return responseEntity;
    }
}

servicec 层

package com.haue.jobonline.service.impl;

import com.haue.jobonline.dao.CompetitionSignUpDao;
import com.haue.jobonline.entity.CompetitionSignUp;
import com.haue.jobonline.service.SignUpService;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.xssf.usermodel.*;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author 赵鑫
 * @Time: 2018/7/22
 * @Email:[email protected]
 */
@Service
public class ExportExcel {
    @Resource
    private CompetitionSignUpDao competitionSignUpDao;
    public List> createExcelRecord(List competitionSignUps) {
        List> listmap = new ArrayList>();
        Map map = new HashMap();
        map.put("sheetName", "sheet1");
        listmap.add(map);
        for (int j = 0; j < competitionSignUps.size(); j++) {
            CompetitionSignUp competitionSignUp=competitionSignUps.get(j);
            Map mapValue = new HashMap();
//            String keys[]    =     {"studentNumber","studentName","studentSex","studentSpecialy","studentClass","time"};//map中的key
            mapValue.put("studentNumber", competitionSignUp.getStudent().getStudentSchoolNum());
            mapValue.put("studentName",competitionSignUp.getStudent().getStudentName());
            mapValue.put("studentSex",competitionSignUp.getStudent().getStudentSex());
            mapValue.put("studentSpecialy",competitionSignUp.getStudent().getStudentSpecialty());
            mapValue.put("studentClass",competitionSignUp.getStudent().getStudentClass());
            mapValue.put("time",competitionSignUp.getSignTime());
            listmap.add(mapValue);
        }
        return listmap;
    }


}

 

工具类

package com.haue.jobonline.utils;

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.util.List;
import java.util.Map;

/**
 * @author 赵鑫
 * @Time: 2018/7/22
 * @Email:[email protected]
 */
public class ExcelUtils {
    /**
     * 创建excel文档，
     *  list 数据
     * @param keys list中map的key数组集合
     * @param columnNames excel的列名
     * */
    public static Workbook createWorkBook(List> list, String []keys, String columnNames[]) {
        // 创建excel工作簿
        Workbook wb = new XSSFWorkbook();
        // 创建第一个sheet（页），并命名
        Sheet sheet = wb.createSheet(list.get(0).get("sheetName").toString());
        // 手动设置列宽。第一个参数表示要为第几列设；，第二个参数表示列的宽度，n为列高的像素数。
        for(int i=0;i