1、工具类ExcelUtil

package com.xxx.xxx.utils;

import cn.afterturn.easypoi.excel.ExcelExportUtil;
import cn.afterturn.easypoi.excel.ExcelImportUtil;
import cn.afterturn.easypoi.excel.entity.ExportParams;
import cn.afterturn.easypoi.excel.entity.ImportParams;
import cn.afterturn.easypoi.excel.entity.enmus.ExcelType;
import com.hualin.crm.common.ResultEnum;
import com.hualin.crm.exception.BizException;
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;

/**
 * @Description Excel导入导出工具类
 * @Auther XGF
 * @Date 2021/3/19 19:37
 * @Version 1.0
 */
public class ExcelUtil {

    //xls 后缀
    private static final String XLS = ".xls";
    //xlsx 后缀
    private static final String XLS_X = ".xlsx";

	/**
     * excel 导出
     *
     * @param list           数据
     * @param title          标题
     * @param sheetName      sheet名称
     * @param pojoClass      pojo类型
     * @param fileName       文件名称
     * @param isCreateHeader 是否创建表头
     * @param response
     */
    public static void exportExcel(List<?> list, String title, String sheetName, Class<?> pojoClass, String fileName, boolean isCreateHeader, HttpServletResponse response)
            throws IOException {
        ExportParams exportParams = new ExportParams(title, sheetName, ExcelType.XSSF);
        exportParams.setCreateHeadRows(isCreateHeader);
        defaultExport(list, pojoClass, fileName, response, exportParams);
    }

    /**
     * excel 导出
     *
     * @param list      数据
     * @param title     标题
     * @param sheetName sheet名称
     * @param pojoClass pojo类型
     * @param fileName  文件名称
     * @param response
     */
    public static void exportExcel(List<?> list, String title, String sheetName, Class<?> pojoClass, String fileName, HttpServletResponse response)
            throws IOException {
        defaultExport(list, pojoClass, fileName, response, new ExportParams(title, sheetName, ExcelType.XSSF));
    }

    /**
     * excel 导出
     *
     * @param list         数据
     * @param pojoClass    pojo类型
     * @param fileName     文件名称
     * @param response
     * @param exportParams 导出参数
     */
    public static void exportExcel(List<?> list, Class<?> pojoClass, String fileName, ExportParams exportParams, HttpServletResponse response)
            throws IOException {
        defaultExport(list, pojoClass, fileName, response, exportParams);
    }

    /**
     * excel 导出
     *
     * @param list     数据
     * @param fileName 文件名称
     * @param response
     */
    public static void exportExcel(List<Map<String, Object>> list, String fileName, HttpServletResponse response)
            throws IOException {
        defaultExport(list, fileName, response);
    }

    /**
     * 默认的 excel 导出
     *
     * @param list         数据
     * @param pojoClass    pojo类型
     * @param fileName     文件名称
     * @param response
     * @param exportParams 导出参数
     */
    private static void defaultExport(List<?> list, Class<?> pojoClass, String fileName, HttpServletResponse response, ExportParams exportParams)
            throws IOException {
        Workbook workbook = ExcelExportUtil.exportExcel(exportParams, pojoClass, list);
        downLoadExcel(fileName, response, workbook);
    }

    /**
     * 默认的 excel 导出
     *
     * @param list     数据
     * @param fileName 文件名称
     * @param response
     */
    private static void defaultExport(List<Map<String, Object>> list, String fileName, HttpServletResponse response)
            throws IOException {
        Workbook workbook = ExcelExportUtil.exportExcel(list, ExcelType.HSSF);
        downLoadExcel(fileName, response, workbook);
    }

    /**
     * 下载
     *
     * @param fileName 文件名称
     * @param response
     * @param workbook excel数据
     */
    private static void downLoadExcel(String fileName, HttpServletResponse response, Workbook workbook)
            throws IOException {
        try {
            response.setCharacterEncoding("UTF-8");
            response.setHeader("content-Type", "application/vnd.ms-excel");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName + "." + ExcelTypeEnum.XLSX.getValue(), "UTF-8"));
            workbook.write(response.getOutputStream());
        } catch (Exception e) {
            throw new IOException(e.getMessage());
        }
    }

    /**
     * excel 导入
     *
     * @param filePath   excel文件路径
     * @param titleRows  标题行
     * @param headerRows 表头行
     * @param pojoClass  pojo类型
     * @param <T>
     * @return
     */
    public static <T> List<T> importExcel(String filePath, Integer titleRows, Integer headerRows, Class<T> pojoClass)
            throws IOException {
        if (StringUtils.isBlank(filePath)) {
            return null;
        }
        ImportParams params = new ImportParams();
        params.setTitleRows(titleRows);
        params.setHeadRows(headerRows);
        params.setNeedSave(true);
        params.setSaveUrl("/excel/");
        try {
            return ExcelImportUtil.importExcel(new File(filePath), pojoClass, params);
        } catch (NoSuchElementException e) {
            throw new IOException("模板不能为空");
        } catch (Exception e) {
            throw new IOException(e.getMessage());
        }
    }

    /**
     * excel 导入
     *
     * @param file      excel文件
     * @param pojoClass pojo类型
     * @param <T>
     * @return
     */
    public static <T> List<T> importExcel(MultipartFile file, Class<T> pojoClass)
            throws IOException {
        return importExcel(file, 0, 1, pojoClass);
    }

    /**
     * excel 导入
     *
     * @param file       excel文件
     * @param titleRows  标题行
     * @param headerRows 表头行
     * @param pojoClass  pojo类型
     * @param <T>
     * @return
     */
    public static <T> List<T> importExcel(MultipartFile file, Integer titleRows, Integer headerRows, Class<T> pojoClass)
            throws IOException {
        return importExcel(file, titleRows, headerRows, false, pojoClass);
    }

    /**
     * excel 导入
     *
     * @param file       上传的文件
     * @param titleRows  标题行
     * @param headerRows 表头行
     * @param needVerfiy 是否检验excel内容
     * @param pojoClass  pojo类型
     * @param <T>
     * @return
     */
    public static <T> List<T> importExcel(MultipartFile file, Integer titleRows, Integer headerRows, boolean needVerfiy, Class<T> pojoClass)
            throws IOException {
        if (file == null) {
            return null;
        }
        try {
            return importExcel(file.getInputStream(), titleRows, headerRows, needVerfiy, pojoClass);
        } catch (Exception e) {
            throw new IOException(e.getMessage());
        }
    }

    /**
     * excel 导入
     *
     * @param inputStream 文件输入流
     * @param titleRows   标题行
     * @param headerRows  表头行
     * @param needVerfiy  是否检验excel内容
     * @param pojoClass   pojo类型
     * @param <T>
     * @return
     */
    public static <T> List<T> importExcel(InputStream inputStream, Integer titleRows, Integer headerRows, boolean needVerfiy, Class<T> pojoClass)
            throws IOException {
        if (inputStream == null) {
            return null;
        }
        ImportParams params = new ImportParams();
        params.setTitleRows(titleRows);
        params.setHeadRows(headerRows);
        params.setSaveUrl("/excel/");
        params.setNeedSave(true);
        params.setNeedVerify(needVerfiy);
        try {
            return ExcelImportUtil.importExcel(inputStream, pojoClass, params);
        } catch (NoSuchElementException e) {
            throw new IOException("excel文件不能为空");
        } catch (Exception e) {
            throw new IOException(e.getMessage());
        }
    }

    /**
     * 检查文件
     * @param file
     */
    public static void checkFile(MultipartFile file) {
        if (file == null) {
            throw new BizException(ResultEnum.FILE_NOT_EXIST);
        }

        String fileName = file.getOriginalFilename();
        assert fileName != null;
        if (!fileName.endsWith(XLS) && !fileName.endsWith(XLS_X)) {
            throw new BizException(ResultEnum.NOT_EXCEL_FILE);
        }
    }

    /**
     * Excel 类型枚举
     */
    enum ExcelTypeEnum {
        XLS("xls"), XLSX("xlsx");
        private String value;

        ExcelTypeEnum(String value) {
            this.value = value;
        }

        public String getValue() {
            return value;
        }

        public void setValue(String value) {
            this.value = value;
        }
    }
}

2、controller类

@PostMapping("/xxx/excelImport")
public Result<Map<String, Object>> excelImport(@RequestParam("file") MultipartFile file) throws IOException {
	Map<String, Object> result = new HashMap<>();
	result.put("successSize", xxxService.excelImport(file));
	return Result.success(result);
}

3、serviceImpl类

@Transactional
@Override
public int excelImport(MultipartFile file) throws IOException {
	//校验Excel文件
	ExcelUtil.checkFile(file);
	List<ExcelCp> excelCps = ExcelUtil.importExcel(file, ExcelCp.class);
	//校验Excel数据
	checkData(excelCps);
	return cpMapper.insertBatch(excelCps);
}

4、接收Excel数据的实体类ExcelCp

@Data
@NoArgsConstructor
@AllArgsConstructor
public class ExcelCp {
    private Integer id;

    @Excel(name = "机构码")
    @NotBlank(message = "机构码不能为空")
    private String code;

    @Excel(name = "方机构名称")
    @NotBlank(message = "机构名称不能为空")
    private String name;

    @Excel(name = "方机构类型", replace = {"银行_1", "券商_2", "基金_3", "信托_4", "私募_5"})
    private Integer type;
}