FastExcel Replaces EasyExcel: Now an Apache Project with Enhanced Performance

FastExcel is an upgraded Java Excel processing framework released by the original EasyExcel author after Alibaba stopped maintaining EasyExcel. It inherits all EasyExcel advantages while delivering significant performance and feature improvements.

Features

High‑performance read/write with low memory consumption.

Simple, intuitive API for quick integration.

Streaming support that minimizes memory usage for tens of thousands to millions of rows.

Full compatibility with EasyExcel APIs, enabling seamless migration.

Ongoing updates for bug fixes, performance tuning, and new capabilities.

Usage

Define Entity Class

Each field maps to an Excel column using @ExcelProperty:

import cn.idev.excel.annotation.ExcelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;

@Setter
@Getter
@ToString
public class User {
    @ExcelProperty("编号")
    private Integer id;
    @ExcelProperty("名字")
    private String name;
    @ExcelProperty("年龄")
    private Integer age;
}

Create Event Listener

The listener processes rows one by one, preventing OOM for large files.

import cn.idev.excel.context.AnalysisContext;
import cn.idev.excel.event.AnalysisEventListener;
import java.util.ArrayList;
import java.util.List;

public class BaseExcelListener<T> extends AnalysisEventListener<T> {
    private List<T> dataList = new ArrayList<>();

    @Override
    public void invoke(T t, AnalysisContext analysisContext) {
        dataList.add(t);
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        System.out.println("读取完成，共读取了 " + dataList.size() + " 条数据");
    }

    public List<T> getDataList() {
        return dataList;
    }
}

Write Excel

@GetMapping("/download")
public void download(HttpServletResponse response) throws IOException {
    response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
    response.setCharacterEncoding("utf-8");
    String fileName = URLEncoder.encode("test", "UTF-8");
    response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileName + ".xlsx");
    FastExcel.write(response.getOutputStream(), User.class)
             .sheet("模板")
             .doWrite(buildData());
}

private List<User> buildData() {
    User user1 = new User();
    user1.setId(1);
    user1.setName("张三");
    user1.setAge(18);
    User user2 = new User();
    user2.setId(2);
    user2.setName("李四");
    user2.setAge(19);
    return List.of(user1, user2);
}

Read Excel

@PostMapping("/upload")
public ResponseEntity<String> upload(@RequestParam("file") MultipartFile file) {
    if (file.isEmpty()) {
        return ResponseEntity.badRequest().body("请选择一个文件上传！");
    }
    try {
        BaseExcelListener<User> listener = new BaseExcelListener<>();
        FastExcel.read(file.getInputStream(), User.class, listener)
                 .sheet()
                 .doRead();
        List<User> dataList = listener.getDataList();
        System.out.println(dataList);
        return ResponseEntity.ok("文件上传并处理成功！");
    } catch (IOException e) {
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
                             .body("文件处理失败！");
    }
}

Convert to PDF

FastExcel can convert an Excel file to PDF using Apache POI and itext‑pdf (license compliance required).

FastExcel.convertToPdf(new File("excelFile"), new File("pdfFile"), null, null);

Comparison with EasyExcel

Performance: FastExcel offers better and more stable performance.

API compatibility: Identical APIs allow seamless switching.

New features in version 1.0.0: ability to read a specific number of rows and PDF conversion.

Conclusion

FastExcel is a lightweight yet powerful Java library designed for high‑performance, low‑memory Excel processing. Its streaming architecture and flexible API make it suitable for handling large‑scale Excel data in enterprise or personal projects.