【开发心得】EasyPoi导入导出的基本使用-摩杜云开发者社区

网上关于Java导入导出Excel 的文章比较多，相对的坑也比较多（或者因为读者个人水平），特根据自己日常开发中的踩坑，写点东西。

1.常见的Java领域Excel导入导出的类库,基础库(Apache common POI,JExcelAPI,JXL等等...),个人觉得apache的这个可能更好一些，毕竟贡献者多，但是有一个很大的问题，就是每次大版本更新，变动就会很大,博主有一篇文章是阐述从低版本POI升级到高版本的POI可能遇到的问题和解决方案. 基于Apache common POI的二次封装工具有EasyExcel(alibaba),EasyPOI.这两者可谓是各有千秋,各有优劣,虽然网上很多都觉得ali的更为强悍一些,但是出现的时间比easypoi时间要晚,相对来说,恼人的坑还是比较多的(建议多读官网文档或者阅读源码),而easypoi在大批量导出的时候对内存的消耗有点厉害.

2.之前看的比较多的版本都是使用easyPOI低版本进行导入导出的,博主这里使用高版本的easypoi,依赖如下.

<!--apache common poi-->
    <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.0.1</version>
        </dependency>
  <!--easypoi-->
        <dependency>
            <groupId>cn.afterturn</groupId>
            <artifactId>easypoi-base</artifactId>
            <version>4.0.0</version>
        </dependency>
        <dependency>
            <groupId>cn.afterturn</groupId>
            <artifactId>easypoi-web</artifactId>
            <version>4.0.0</version>
        </dependency>
        <dependency>
            <groupId>cn.afterturn</groupId>
            <artifactId>easypoi-annotation</artifactId>
            <version>4.0.0</version>
        </dependency>

3.工具类:

package com.hmwl.media.modules.ma.util; //换成你自己的包


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 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;

/**
 * Created by martin on 2020/3/12 0012 13:50
 */
public class EasyPoiUtil {
        /**
         * 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 {
            // map中需要添加k
            // title 对应表格Title
            // key entity 对应表格对应实体
            // key data Collection 数据
            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
         */
        public 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, 1, 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());
            }
        }

        /**
         * 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;
            }
        }

    }

4.普通导入

可以选择使用模型注解导入

package [换成自己的包].vo;

import cn.afterturn.easypoi.excel.annotation.Excel;
import lombok.Data;

import java.io.Serializable;

@Data
public class MenuButtonExcel implements Serializable {
    @Excel(name = "primary_id", orderNum = "1", width = 20)   //注意这里的name 要和excel的列名完全一致 orderNum是指的第几列,注意从1开始,width是指宽度
    private String primary_id;
    @Excel(name = "parent_id", orderNum = "2", width = 20)
    private String parent_id;
    @Excel(name = "parent_ids", orderNum = "3", width = 20)
    private String parent_ids;
    @Excel(name = "code", orderNum = "4", width = 20)
    private String code;
    @Excel(name = "name", orderNum = "5", width = 20)
    private String name;
    @Excel(name = "href", orderNum = "6", width = 20)
    private String href;
    @Excel(name = "level", orderNum = "6", width = 20)
    private String level;
    @Excel(name = "type", orderNum = "8", width = 20)
    private String type;
    @Excel(name = "sequence", orderNum = "9", width = 20)
    private String sequence;
    @Excel(name = "permission", orderNum = "10", width = 20)
    private String permission;
    @Excel(name = "is_sys", orderNum = "11", width = 20)
    private String is_sys;
    @Excel(name = "del_flag", orderNum = "17", width = 20)
    private String del_flag;
}

注意这里的name 要和excel的列名完全一致 orderNum是指的第几列,注意从1开始,width是指宽度(如果name对不起来,可能会导致读取出现Null的问题)

5.核心实现代码(service)

String path = null;
        try {
            path = ResourceUtils.getURL("classpath:").getPath();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        List<MenuButtonExcel> list = null;
        try {
            list = EasyPoiUtil.importExcel(path+"权限接入拟定表.xlsx", 0, 1, MenuButtonExcel.class);
        } catch (IOException e) {
            e.printStackTrace();
        }
        Integer result = -1;
        for (MenuButtonExcel ex:list) {
            logger.info(ex.toString());
            result = systemSettingMapper.importPermission(ex);
        }

6.导出

导出的话,方法也是很多,比如直接通过pojo类导出,或者使用模型导出.

但是要注意的问题有:1.如果想导出忽略某个列使用@ExcelIgnore

模型导出示例代码:

List<ExcelProgram> excelPrograms = null;
try {
   excelPrograms = EasyPoiUtil.importExcel(fileUrl,0,1,ExcelProgram.class);
} catch (IOException e) {
   e.printStackTrace();
}

List<Map<String,Object>>导出的话,请注意源码.(EasyExportUtil)

public static Workbook exportExcel(List<Map<String, Object>> list, ExcelType type) {
    Workbook workbook = getWorkbook(type, 0);
    Iterator var3 = list.iterator();

    while(var3.hasNext()) {
        Map<String, Object> map = (Map)var3.next();
        ExcelExportService service = new ExcelExportService();
        service.createSheet(workbook, (ExportParams)map.get("title"), (Class)map.get("entity"), (Collection)map.get("data"));
    }

    return workbook;
}

有几个key 是需要的 title 对应的标题,entity对应的是实体,data对应的是数据:

public static Workbook exportExcel(TemplateExportParams params, Class<?> pojoClass, Collection<?> dataSet, Map<String, Object> map) {
    return (new ExcelExportOfTemplateUtil()).createExcleByTemplate(params, pojoClass, dataSet, map);
}

另外一个方法可以供【动态导出列使用】

public static Workbook exportExcel(TemplateExportParams params, Class<?> pojoClass, Collection<?> dataSet, Map<String, Object> map) { return (new ExcelExportOfTemplateUtil()).createExcleByTemplate(params, pojoClass, dataSet, map); }