SpringBoot POI导出Excel

SpringBoot导出Excel

HSSFWorkbook、XSSFWorkbook、SXSSFWorkbook的区别:

HSSFWorkbook一般用于Excel2003版及更早版本(扩展名为.xls)的导出。
XSSFWorkbook一般用于Excel2007版(扩展名为.xlsx)的导出。
SXSSFWorkbook一般用于大数据量的导出。

注：HSSFWorkbook和XSSFWorkbook的Excel Sheet导出条数上限(<=2003版)是65535行、256列,(>=2007版)是
1048576行,16384列,如果数据量超过了此上限,那么可以使用SXSSFWorkbook来导出。实际上上万条数据，
甚至上千条数据就可以考虑使用SXSSFWorkbook了。

HSSSFWorkbook 和SXSSFWorkbook在导出excel workbook对象在执行write方法写入数据到ServletOutputStream时是有点区别的

HSSFWorkbook在write方法执行完的时候并没有关闭流，所以我们可以对这个流统计大小来获取导出文件的大小，并且最后需要我们手动关闭
而SXSSFWorkbook的write方法把流关闭了，write方法执行完之后out流就空了拿不到大小了

SXSSFWorkbook是XSSFWorkbook的Streaming版本，实现了"BigGridDemo"的策略，在导出大量数据的时候，可以避免OOM。

<dependency><groupId>org.apache.poi</groupId><artifactId>poi</artifactId><version>4.1.2</version>
</dependency>
<dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>4.1.2</version>
</dependency>
<dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml-schemas</artifactId><version>4.1.2</version>
</dependency>

getFirstRowNum、getLastRowNum 起始都是0

接口代码

//上传Excel
@RequestMapping("/uploadDevMachine")
public Object uploadDevMachine(MultipartFile file) {int successCount = 0;//上传成功条数try {if(file == null || file.isEmpty()){return Rsp.end(Result.Err.ERR_NOT_EXISTS);}XSSFWorkbook workbook = new XSSFWorkbook(file.getInputStream());XSSFSheet sheet = workbook.getSheetAt(0);int lastRowNum = sheet.getLastRowNum();if(lastRowNum < 1){return Rsp.end(Result.Err.ERR_NO_RECORD);}logger.info("import file name:{}, lastRowNum:{}",file.getOriginalFilename(), lastRowNum);for(int i = 1; i <= lastRowNum; i++){XSSFRow row = sheet.getRow(i);//包装实体类DevMachine dm = new DevMachine();dm.number = row.getCell(0) == null ? "" : row.getCell(0).getStringCellValue();dm.name = row.getCell(1) == null ? "" : row.getCell(1).getStringCellValue();if(row.getCell(2) != null){dm.meterId = row.getCell(2).getStringCellValue();//计量插座Id唯一索引}if(row.getCell(3) != null){dm.tagId = row.getCell(3).getStringCellValue();电子标签Id唯一索引}dm.remark = row.getCell(4) == null ? "" : row.getCell(4).getStringCellValue();if(cu.isCustomer()){dm.customerId = cu.userId;//所属用户}//判断id是否为空XSSFCell cell = row.getCell(5);if(cell == null){dm.id = Misc.makeUuid();boolean add = devMachineService.addDevMachine(dm);if(add){successCount++;}}else{dm.id = cell.getStringCellValue();if(dm.id.length() > 20){boolean update = devMachineService.updateDevMachine(dm);if(update){successCount++;}}}}}catch(Exception e){e.printStackTrace();}return Rsp.end(Result.Err.SUCCESS, "上传成功条数:" + successCount);
}

前端代码

<el-dialog title="导入" width="30%" :visible.sync="handleUploadVisible"><el-upload class="upload-demo" drag style="display: inline-block;" action="#" :file-list="fileList" :on-change="handleChange" :limit="1" :http-request="dragSubmit" accept="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet,application/vnd.ms-excel" :auto-upload="false"><i class="el-icon-upload"></i><div class="el-upload__text">将Excel文件拖到此处，或<em>点击上传</em></div><div class="el-upload__tip" slot="tip">提示：文件格式为.xlsx</div></el-upload><div class="dialog-footer" slot="footer"><el-button @click="handleUploadVisible=false">取消</el-button><el-button @click="exportDevMachine()">下载模板</el-button><el-button @click="doUploadFile()" slot="trigger">确定</el-button></div>
</el-dialog>

methods

handleUpload(){this.handleUploadVisible = true},handleChange(file, fileList){this.fileTemp = file.raw//console.log(file)},handleRemove(file, fileList){this.fileTemp = null;},dragSubmit(param){console.log('---dragSubmit param---')this.fileTemp = param.file;//fetchPost("uploadDevMachine", formData).then((rsp) => {})//自动上传},upload() {//console.log("do upload refs submit")this.$refs.upload.submit();},/* 手动上传excel文件 */doUploadFile(){if(this.fileTemp == null){this.$message.success("未选择上传的excel文件！")return}//console.log(this.fileList[0].raw)//console.log(this.fileTemp)//const formData = new FormData();formData.append("file", this.fileTemp);fetchPost("uploadData", formData).then((rsp) => {if (rsp.code == 0) {this.$message.success(rsp.msg)return}this.$message.error(rsp.msg)})},

参考地址
https://www.cnblogs.com/linjiqin/p/10975761.html

https://www.jianshu.com/p/3a89e19a1bc3

https://www.cnblogs.com/toutou/p/9857963.html

https://blog.csdn.net/typ1805/article/details/83279532

POI之SXSSFWorkbook大量数据导出至excel
https://blog.csdn.net/k_520_w/article/details/84404652