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。 github地址:https://github.com/alibaba/easyexcel
https://www.yuque.com/easyexcel/doc/easyexcel
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>3.0.5</version>
</dependency>
上传下载示例:
/**
* 文件下载(失败了会返回一个有部分数据的Excel)
* <p>1. 创建excel对应的实体对象 参照{@link DownloadData}
* <p>2. 设置返回的 参数
* <p>3. 直接写,这里注意,finish的时候会自动关闭OutputStream,当然你外面再关闭流问题不大
*/
@GetMapping("download")
public void download(HttpServletResponse response) throws IOException {
// 这里注意 有同学反应使用swagger 会导致各种问题,请直接用浏览器或者用postman
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf-8");
// 这里URLEncoder.encode可以防止中文乱码 当然和easyexcel没有关系
String fileName = URLEncoder.encode("测试", "UTF-8");
response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
EasyExcel.write(response.getOutputStream(), DownloadData.class).sheet("模板").doWrite(data());
}
/**
* 文件上传
* <p>1. 创建excel对应的实体对象 参照{@link UploadData}
* <p>2. 由于默认一行行的读取excel,所以需要创建excel一行一行的回调监听器,参照{@link UploadDataListener}
* <p>3. 直接读即可
*/
@PostMapping("upload")
@ResponseBody
public String upload(MultipartFile file) throws IOException {
EasyExcel.read(file.getInputStream(), UploadData.class, new UploadDataListener(uploadDAO)).sheet().doRead();
return "success";
}
动态单元格使合并
import com.alibaba.excel.metadata.CellData;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.write.handler.CellWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
import lombok.Data;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddress;
import java.util.List;
/**
* 单元格合并
*
*/
@SuppressWarnings("rawtypes")
@Data
public class ExcelFillCellMergeStrategy implements CellWriteHandler {
/**
* 合并字段的下标
*/
private int[] mergeColumnIndex;
/**
* 合并几行
*/
private int mergeRowIndex;
/**
* 作为唯一的合并条件
*/
private Integer unqiueColumnIndex;
public ExcelFillCellMergeStrategy() {
}
public ExcelFillCellMergeStrategy(int mergeRowIndex, int[] mergeColumnIndex) {
this.mergeRowIndex = mergeRowIndex;
this.mergeColumnIndex = mergeColumnIndex;
}
public ExcelFillCellMergeStrategy(int mergeRowIndex, int[] mergeColumnIndex,Integer unqiueColumnIndex) {
this.mergeRowIndex = mergeRowIndex;
this.mergeColumnIndex = mergeColumnIndex;
this.unqiueColumnIndex = unqiueColumnIndex;
}
@Override
public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row,
Head head, Integer integer, Integer integer1, Boolean aBoolean) {
}
@Override
public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Cell cell,
Head head, Integer integer, Boolean aBoolean) {
}
@Override
public void afterCellDataConverted(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder,
CellData cellData, Cell cell, Head head, Integer integer, Boolean aBoolean) {
}
@Override
public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder,
List<CellData> list, Cell cell, Head head, Integer integer, Boolean aBoolean) {
//当前行
int curRowIndex = cell.getRowIndex();
//当前列
int curColIndex = cell.getColumnIndex();
if (curRowIndex > mergeRowIndex) {
for (int i = 0; i < mergeColumnIndex.length; i++) {
if (curColIndex == mergeColumnIndex[i]) {
mergeWithPrevRow(writeSheetHolder, cell, curRowIndex, curColIndex);
break;
}
}
}
}
private void mergeWithPrevRow(WriteSheetHolder writeSheetHolder, Cell cell, int curRowIndex, int curColIndex) {
String currentPrexValue ="";
String prexPrexValue ="";
if(this.unqiueColumnIndex!=null) {
Cell currentPrexCell=cell.getSheet().getRow(curRowIndex).getCell(unqiueColumnIndex);
if(currentPrexCell!=null) {
currentPrexValue= currentPrexCell.getCellTypeEnum() == CellType.STRING ?currentPrexCell.getStringCellValue():String.valueOf(currentPrexCell.getNumericCellValue());
}
Cell prexPrexCell=cell.getSheet().getRow(curRowIndex-1).getCell(unqiueColumnIndex);
prexPrexValue= prexPrexCell.getCellTypeEnum() == CellType.STRING ?prexPrexCell.getStringCellValue():String.valueOf(prexPrexCell.getNumericCellValue());
}
//获取当前行的当前列的数据和上一行的当前列列数据,通过上一行数据是否相同进行合并
Object curData = cell.getCellTypeEnum() == CellType.STRING ? cell.getStringCellValue() :
cell.getNumericCellValue();
Cell preCell = cell.getSheet().getRow(curRowIndex - 1).getCell(curColIndex);
Object preData = preCell.getCellTypeEnum() == CellType.STRING ? preCell.getStringCellValue() :
preCell.getNumericCellValue();
// 比较当前行的第一列的单元格与上一行是否相同,相同合并当前单元格与上一行
//
if (curData.equals(preData) && currentPrexValue.equals(prexPrexValue)) {
Sheet sheet = writeSheetHolder.getSheet();
List<CellRangeAddress> mergeRegions = sheet.getMergedRegions();
boolean isMerged = false;
for (int i = 0; i < mergeRegions.size() && !isMerged; i++) {
CellRangeAddress cellRangeAddr = mergeRegions.get(i);
// 若上一个单元格已经被合并,则先移出原有的合并单元,再重新添加合并单元
if (cellRangeAddr.isInRange(curRowIndex - 1, curColIndex)) {
sheet.removeMergedRegion(i);
cellRangeAddr.setLastRow(curRowIndex);
sheet.addMergedRegion(cellRangeAddr);
isMerged = true;
}
}
// 若上一个单元格未被合并,则新增合并单元
if (!isMerged) {
CellRangeAddress cellRangeAddress = new CellRangeAddress(curRowIndex - 1, curRowIndex, curColIndex,
curColIndex);
sheet.addMergedRegion(cellRangeAddress);
}
}
}
}