【開發心得】EasyPoi導入導出的基本使用

網上關於Java導入導出Excel 的文章比較多，相對的坑也比較多（或者因爲讀者個人水平），特根據自己日常開發中的踩坑，寫點東西。

1.常見的Java領域Excel導入導出的類庫,基礎庫(Apache common POI,JExcelAPI,JXL等等...),個人覺得apache的這個可能更好一些，畢竟貢獻者多，但是有一個很大的問題，就是每次大版本更新，變動就會很大,博主有一篇文章是闡述從低版本POI升級到高版本的POI可能遇到的問題和解決方案. 基於Apache common POI的二次封裝工具有EasyExcel(alibaba),EasyPOI.這兩者可謂是各有千秋,各有優劣,雖然網上很多都覺得ali的更爲強悍一些,但是出現的時間比easypoi時間要晚,相對來說,惱人的坑還是比較多的(建議多讀官網文檔或者閱讀源碼),而easypoi在大批量導出的時候對內存的消耗有點厲害.

2.之前看的比較多的版本都是使用easyPOI低版本進行導入導出的,博主這裏使用高版本的easypoi,依賴如下.

      <!--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.工具類:

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


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 導出
         *
         * @param list           數據
         * @param title          標題
         * @param sheetName      sheet名稱
         * @param pojoClass      pojo類型
         * @param fileName       文件名稱
         * @param isCreateHeader 是否創建表頭
         * @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 導出
         *
         * @param list      數據
         * @param title     標題
         * @param sheetName sheet名稱
         * @param pojoClass pojo類型
         * @param fileName  文件名稱
         * @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 導出
         *
         * @param list         數據
         * @param pojoClass    pojo類型
         * @param fileName     文件名稱
         * @param response
         * @param exportParams 導出參數
         */
        public static void exportExcel(List<?> list, Class<?> pojoClass, String fileName, ExportParams exportParams, HttpServletResponse response) throws IOException {
            defaultExport(list, pojoClass, fileName, response, exportParams);
        }

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

        /**
         * 默認的 excel 導出
         *
         * @param list         數據
         * @param pojoClass    pojo類型
         * @param fileName     文件名稱
         * @param response
         * @param exportParams 導出參數
         */
        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);
        }

        /**
         * 默認的 excel 導出
         *
         * @param list     數據
         * @param fileName 文件名稱
         * @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 對應表格Title
            // key entity 對應表格對應實體
            // key data Collection 數據
            Workbook workbook = ExcelExportUtil.exportExcel(list, ExcelType.HSSF);
            downLoadExcel(fileName, response, workbook);
        }

        /**
         * 下載
         *
         * @param fileName 文件名稱
         * @param response
         * @param workbook excel數據
         */
        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 導入
         *
         * @param filePath   excel文件路徑
         * @param titleRows  標題行
         * @param headerRows 表頭行
         * @param pojoClass  pojo類型
         * @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("模板不能爲空");
            } catch (Exception e) {
                throw new IOException(e.getMessage());
            }
        }

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

        /**
         * excel 導入
         *
         * @param file       excel文件
         * @param titleRows  標題行
         * @param headerRows 表頭行
         * @param pojoClass  pojo類型
         * @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 導入
         *
         * @param file       上傳的文件
         * @param titleRows  標題行
         * @param headerRows 表頭行
         * @param needVerfiy 是否檢驗excel內容
         * @param pojoClass  pojo類型
         * @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 導入
         *
         * @param inputStream 文件輸入流
         * @param titleRows   標題行
         * @param headerRows  表頭行
         * @param needVerfiy  是否檢驗excel內容
         * @param pojoClass   pojo類型
         * @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文件不能爲空");
            } catch (Exception e) {
                throw new IOException(e.getMessage());
            }
        }

        /**
         * Excel 類型枚舉
         */
        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.普通導入

可以選擇使用模型註解導入

package [換成自己的包].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)   //注意這裏的name 要和excel的列名完全一致 orderNum是指的第幾列,注意從1開始,width是指寬度
    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;
}

注意這裏的name 要和excel的列名完全一致 orderNum是指的第幾列,注意從1開始,width是指寬度(如果name對不起來,可能會導致讀取出現Null的問題)

5.核心實現代碼(service)

 String path = null;
        try {
            path = ResourceUtils.getURL("classpath:").getPath();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        List<MenuButtonExcel> list = null;
        try {
            list = EasyPoiUtil.importExcel(path+"權限接入擬定表.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.導出

導出的話,方法也是很多,比如直接通過pojo類導出,或者使用模型導出.

但是要注意的問題有:1.如果想導出忽略某個列使用@ExcelIgnore

模型導出示例代碼:

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

List<Map<String,Object>>導出的話,請注意源碼.(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;
}

有幾個key 是需要的 title 對應的標題,entity對應的是實體,data對應的是數據:

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

另外一個方法可以供【動態導出列使用】

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

【開發心得】EasyPoi導入導出的基本使用

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