1 EasyExcel简介

EasyExcel是一个基于Java的简单、省内存的读写Excel的开源项目。在尽可能节约内存的情况下支持读写百M的Excel。由阿里巴巴EasyExcel团队开发

官方文档：https://easyexcel.opensource.alibaba.com/

gitee地址：https://gitee.com/easyexcel/easyexcel

B站学习视频: https://www.bilibili.com/video/BV1Ff4y1U7Qc

Excel解析流程图:

2 EasyExcel使用 

2.1 添加maven依赖

    <dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>3.3.2</version></dependency>

2.2 框架工具说明

2.3.1 EasyExcelUtils工具类

/*** 类描述：easyexcel工具类*/
public class EasyExcelUtils<T> extends EasyExcel {/**************************** 导出 ******************************************//*** 导出excel** @param list      导出数据集合* @param sheetName 工作表的名称* @param clazz     实体类* @param response  响应体*/public static <T> void exportExcel(List<T> list, String sheetName, Class<T> clazz, HttpServletResponse response) {try {resetResponse(sheetName, response);ServletOutputStream os = response.getOutputStream();exportExcel(list, sheetName, clazz, false, os);} catch (IOException e) {throw new RuntimeException("导出Excel异常");}}/*** 导出excel** @param list      导出数据集合* @param sheetName 工作表的名称* @param clazz     实体类* @param merge     是否合并单元格* @param os        输出流*/public static <T> void exportExcel(List<T> list, String sheetName, Class<T> clazz, boolean merge,OutputStream os) {ExcelWriterSheetBuilder builder = EasyExcel.write(os, clazz).autoCloseStream(false)// 自动适配.registerWriteHandler(new LongestMatchColumnWidthStyleStrategy())// 大数值自动转换 防止失真.registerConverter(new ExcelBigNumberConvert()).sheet(sheetName);if (merge) {// 合并处理器builder.registerWriteHandler(new CellMergeStrategy(list, true));}builder.doWrite(list);}/*** 重置响应体*/private static void resetResponse(String sheetName, HttpServletResponse response) throws UnsupportedEncodingException {String filename = encodingFilename(sheetName);FileUtils.setAttachmentResponseHeader(response, filename);response.setContentType("appl