springboot 实现后端接口操作Excel的导出、批量导入功能

　　 <!--poi  operate excel-->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>RELEASE</version>
        </dependency>

package com.xj.demo.common;


import com.xj.demo.model.Request.ExcelData;
import lombok.extern.slf4j.Slf4j;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;

import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import static org.apache.poi.ss.usermodel.CellType.*;

/**
 * Excel 工具类
 * **/
@Slf4j
public class ExcelUtil {

    /**
     * 方法名：exportExcel
     * 功能：导出Excel
     */
    public static void exportExcel(HttpServletResponse response, ExcelData data) {
        log.info("导出解析开始，fileName:{}",data.getFileName());
        try {
            //实例化HSSFWorkbook
            HSSFWorkbook workbook = new HSSFWorkbook();
            //创建一个Excel表单，参数为sheet的名字
            HSSFSheet sheet = workbook.createSheet("sheet");
            //设置表头
            setTitle(workbook, sheet, data.getHead());
            //设置单元格并赋值
            setData(sheet, data.getData());
            //设置浏览器下载
            setBrowser(response, workbook, data.getFileName());
            log.info("导出解析成功!");
        } catch (Exception e) {
            log.info("导出解析失败!");
            e.printStackTrace();
        }
    }

 /**
  * setTitle设置标题
  * */
    private static void setTitle(HSSFWorkbook workbook, HSSFSheet sheet, String[] str) {
        try {
            HSSFRow row = sheet.createRow(0);
            //设置列宽，setColumnWidth的第二个参数要乘以256，这个参数的单位是1/256个字符宽度
            for (int i = 0; i <= str.length; i++) {
                sheet.setColumnWidth(i, 15 * 256);
            }
            //设置为居中加粗,格式化时间格式
            HSSFCellStyle style = workbook.createCellStyle();
            HSSFFont font = workbook.createFont();
            font.setBold(true);
            style.setFont(font);
            style.setDataFormat(HSSFDataFormat.getBuiltinFormat("m/d/yy h:mm"));
            //创建表头名称
            HSSFCell cell;
            for (int j = 0; j < str.length; j++) {
                cell = row.createCell(j);
                cell.setCellValue(str[j]);
                cell.setCellStyle(style);
            }
        } catch (Exception e) {
            log.info("导出时设置表头失败！");
            e.printStackTrace();
        }
    }

    /**
     * 方法名：setData
     * 功能：表格赋值
     */
    private static void setData(HSSFSheet sheet, List<String[]> data) {
        try{
            int rowNum = 1;
            for (int i = 0; i < data.size(); i++) {
                HSSFRow row = sheet.createRow(rowNum);
                for (int j = 0; j < data.get(i).length; j++) {
                    row.createCell(j).setCellValue(data.get(i)[j]);
                }
                rowNum++;
            }
            log.info("表格赋值成功！");
        }catch (Exception e){
            log.info("表格赋值失败！");
            e.printStackTrace();
        }
    }

    /**
     * 方法名：setBrowser
     * 功能：使用浏览器下载
     */
    private static void setBrowser(HttpServletResponse response, HSSFWorkbook workbook, String fileName) {
        try {
            //清空response
            response.reset();
            //设置response的Header
            response.addHeader("Content-Disposition", "attachment;filename=" + fileName);
            OutputStream os = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/vnd.ms-excel;charset=gb2312");
            //将excel写入到输出流中
            workbook.write(os);
            os.flush();
            os.close();
            log.info("设置浏览器下载成功！");
        } catch (Exception e) {
            log.info("设置浏览器下载失败！");
            e.printStackTrace();
        }

    }


    /**
     * 方法名：importExcel
     * 功能：导入
     */
    public static List<Object[]> importExcel(String fileName) {
        log.info("导入解析开始，fileName:{}",fileName);
        try {
            List<Object[]> list = new ArrayList<>();
            InputStream inputStream = new FileInputStream(fileName);
            Workbook workbook = WorkbookFactory.create(inputStream);
            Sheet sheet = workbook.getSheetAt(0);
            //获取sheet的行数
            int rows = sheet.getPhysicalNumberOfRows();
            for (int i = 0; i < rows; i++) {
                //过滤表头行
                if (i == 0) {
                    continue;
                }
                //获取当前行的数据
                Row row = sheet.getRow(i);
                Object[] objects = new Object[row.getPhysicalNumberOfCells()];
                int index = 0;
                for (Cell cell : row) {
                    if (cell.getCellType().equals(NUMERIC)) {
                        objects[index] = (int) cell.getNumericCellValue();
                    }
                    if (cell.getCellType().equals(STRING)) {
                        objects[index] = cell.getStringCellValue();
                    }
                    if (cell.getCellType().equals(BOOLEAN)) {
                        objects[index] = cell.getBooleanCellValue();
                    }
                    if (cell.getCellType().equals(ERROR)) {
                        objects[index] = cell.getErrorCellValue();
                    }
                    index++;
                }
                list.add(objects);
            }
            log.info("导入文件解析成功！");
            return list;
        }catch (Exception e){
            log.info("导入文件解析失败！");
            e.printStackTrace();
        }
        return null;
    }

}

package com.xj.demo.common;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.ResourceUtils;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
import java.util.UUID;

public class FileUtil {
    private final static Logger logger = LoggerFactory.getLogger(FileUtil.class);

    public static String uploadFile(MultipartFile multipartFile) throws Exception {
        String fileName = UUID.randomUUID().toString() + ".xls";
        String path = ResourceUtils.getURL("classpath:").getPath() + "static/upload/";
        File file = new File(path);
        if (!file.exists()) {
            file.mkdirs();
        }
        String fileFullPath = path + fileName;
        logger.info("fileFullPath:" + fileFullPath);
        InputStream inputStream = null;
        FileOutputStream fos = null;
        try {
            inputStream = multipartFile.getInputStream();
            BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
            fos = new FileOutputStream(fileFullPath);
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fos);
            int size = multipartFile.getBytes().length;
            byte[] buffer = new byte[1024];// 一次读多个字节
            while ((size = inputStream.read(buffer, 0, buffer.length)) != -1) {
                fos.write(buffer, 0, buffer.length);
            }
        } catch (Exception ex) {
            logger.error("ex:" + ex.getMessage());
        } finally {
            if (inputStream != null) {
                inputStream.close();
            }
            if (fos != null) {
                fos.close();
            }
        }
        return fileFullPath;
    }
    /*
    * 获取文件扩展名 小写
    * */
    public static String getFileExt(String fileName) {
        String ext = "";
        try {
            if (!fileName.equals("")) {
                ext = fileName.substring(fileName.lastIndexOf(".")).toLowerCase();
            }
        } catch (Exception e) {
            ext = "";
        }
        return ext;
    }

}

  @ApiOperation("导出用户信息")
    @PostMapping("/exportuserinfo")
    public Result ExportUserInfo(@RequestBody User_InfoListRequest userInfo) {
        try {
            logger.info("user/exportuserinfo：");
            ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
            HttpServletResponse response = requestAttributes.getResponse();
            SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            userInfo.pageSize = 10000;//导出最大1W条
            List<User_info> selectlists = userService.selectList(userInfo);//返回集合和分页之前不要有其它代码，这两行上下要紧靠近
            if (!CollectionUtils.isEmpty(selectlists)) {
                //excel列头信息
                String[] heads = {"姓名", "年龄", "注册时间"};
                List<String[]> dataList = new ArrayList<String[]>();
                String[] objs = null;
                for (int i = 0; i < selectlists.size(); i++) {
                    User_info user = selectlists.get(i);
                    objs = new String[heads.length];
                    objs[0] = String.valueOf(user.getUname());
                    objs[1] = String.valueOf(user.getUage());
                    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    objs[2] = df.format(user.getCreate_time());
                    dataList.add(objs);
                }
                ExcelData excelData = new ExcelData();
                excelData.setFileName(UUID.randomUUID().toString() + ".xls");
                excelData.setHead(heads);
                excelData.setData(dataList);
                ExcelUtil.exportExcel(response, excelData);
                return Result.SUCCESS();
            }
        } catch (Exception ex) {
            logger.error("user/exportuserinfo：" + ex.getMessage());
        }
        return Result.FAIL();
    }

    @ApiOperation("导入用户信息")
    @PostMapping("/inportuserinfo")
    public Result InportUserInfo(@RequestParam("file") MultipartFile multipartFile) throws Exception {
        try {
            logger.info("user/inportuserinfo：");
            String[] extObjs={".xls",".xlsx"};
            String fileName = multipartFile.getOriginalFilename();
            String ext = FileUtil.getFileExt(fileName);
            if (!Arrays.asList(extObjs).contains(ext))
                return Result.FAIL("文件为空或文件格式不正确!");
            String path = FileUtil.uploadFile(multipartFile);
            List<Object[]> objs = ExcelUtil.importExcel(path);
            List<User_info> list = new ArrayList<>();
            if (CollectionUtils.isEmpty(objs))
                return Result.FAIL();
            for (int i = 0; i < objs.size(); i++) {
                User_info user = new User_info();
                Object[] obj = objs.get(i);
                user.setId(UUID.randomUUID().toString());
                user.setUname(String.valueOf(obj[0]));
                user.setUage(Integer.parseInt(String.valueOf(obj[1])));
                user.setCreate_time(new Date());
                list.add(user);
            }
            int result = userService.addBatchUser(list);
            if (result > 0)
                return Result.SUCCESS();
            return Result.FAIL();
        } catch (Exception ex) {
            logger.error("user/inportuserinfo：" + ex.getMessage());
            return Result.FAIL(ex.getMessage());
        }
    }