EasyExcel 写入（导出）
互联网的精髓就是共享，可以共享技术、共享经验、共享情感、共享快乐~
很多年前就有这个想法了，从事IT行业时间也不短了，应该把自己工作和业余所学习的东西记录并分享出来，和有缘人一起学习和交流。
如果您是那个有缘人，请上岛一叙！爪哇岛随时欢迎您！
今天，咱们一起来看看使用EasyExcel做Excel的导出（数据写入到Excel中）。。。。。。 EasyExcel导出Excel在官网（EasyExcel官网-导出数据）上面已经有很多基础的例子，这些我再重复摘抄一遍就没有啥意义了，这部分大家可以根据自己的实际场景自己去官网查找例子代码即可； 本篇文章我主要分享的是：如何通过反射机制封装一些较为复杂的动态场景下的工具类，使用工具类来帮我们减少重复劳动，让生成报表变得很简单。 功能列表：最简单的Excel导出
通过registerWriteHandler控制单元格样式
通过head自定义表头
合并表头（静态）
动态表头（动态合并表头 & 横向无限扩展列）
多sheet页
代码片段 @Data public class Student { @ExcelIgnore private String stuId; @ExcelProperty("姓名", index=0) private String name; @ExcelProperty("学科", index=1) private String subject; @ExcelProperty("分数", index=2) private Double score; } public Object exportExcel(Class <? > excelBeanClass, List < List <? >> dataList, String title) { File file = new File(CommonConstants.CDN_FILE_LOCAL_REPORT); boolean mkdir = true; if(!file.exists()) { mkdir = file.mkdirs(); } if(!mkdir) { return new ASOError(CommonConstants.ErrorEnum.OPRATION_FAIL.getCode(), "创建文件失败"); } String fileName = title + "_" + System.currentTimeMillis() + ".xlsx"; String filePath = CommonConstants.CDN_FILE_LOCAL_REPORT + File.separator + fileName; // 核心 witeExcel(filePath, title, excelBeanClass, dataList); ObjectResponse < String > resp = new ObjectResponse < > (); String downloadPath = CommonConstants.CDN_FILE_REMOTE + "report" + File.separator + fileName; resp.setData(downloadPath); logger.info("generateReport: downloadPath={}", downloadPath); return resp; }最简单的Excel导出
public void witeExcel(String file, String title, Class <? > excelBeanClass, List < List <? >> dataList) { ExcelWriterBuilder write = EasyExcel.write(filePath, excelBeanClass); write.autoCloseStream(true).sheet(title).doWrite(dataList); } public static void main(String []args) { List < List <? >> data = new ArrayList(); ...... System.out.println("download url is :" + exportExcel(Student.class, data, "Excel名称")); }通过registerWriteHandler控制单元格样式
public void witeExcel(String file, String title, Class <?> excelBeanClass, List <List<?>> dataList, List<WriteHandler> writeHandlerList) { ExcelWriterBuilder write = EasyExcel.write(filePath, excelBeanClass); if(CollectionUtils.isNotEmpty(writeHandlerList)) { **writeHandlerList.forEach(write::registerWriteHandler);** } write.autoCloseStream(true).sheet(title).doWrite(dataList); } public static void main(String []args) { //获取头和内容的策略 WriteCellStyle headWriteCellStyle = new WriteCellStyle(); WriteFont headWriteFont = new WriteFont(); headWriteCellStyle.setWriteFont(headWriteFont); // ...内容单元格也可以同样方式设置样式... WriteCellStyle contentWriteCellStyle = new WriteCellStyle(); HorizontalCellStyleStrategy horizontalCellStyleStrategy = new HorizontalCellStyleStrategy(headWriteCellStyle， contentWriteCellStyle); //列宽的策略,宽度是小单位 Integer columnWidthArr[] = {3000, 3000, 2000, 6000}; List<Integer> columnWidths = Arrays.asList(columnWidthArr); CustomSheetWriteHandler customSheetWriteHandler = new CustomSheetWriteHandler(columnWidths); //自定义单元格策略 CustomCellWriteHandler = new CustomCellWriteHandler(yellowRowsSet); List<WriteHandler> writeHandlerList = new ArrayList(); writeHandlerList.add(horizontalCellStyleStrategy); writeHandlerList.add(customSheetWriteHandler); writeHandlerList.add(customCellWriteHandler); List<List<Student>> data = new ArrayList(); ...... System.out.println("download url is :" + exportExcel(Student.class, data, "Excel名称")); }通过head自定义表头
public void witeExcel(String file, String title, List<List<String>> head, List < List <? >> dataList) { ExcelWriterBuilder = EasyExcel.write(filePath); // head可以根据需要自定义 **write.head(head);** write.autoCloseStream(true).sheet(title).doWrite(dataList); } public static void main(String []args) { List < List <? >> data = new ArrayList(); ...... System.out.println("download url is :" + exportExcel(Student.class, data, "Excel名称")); }合并表头（静态）
@Data public class Student { @ExcelIgnore private String stuId; @ExcelProperty(value="姓名", index=0) private String name; @ExcelProperty(value="成绩, 学科", index=1) private String subject; @ExcelProperty(value="成绩, 分数", index=2) private Double score; } 姓名 成绩学科 分数
AAA 语文 100