EasyExcel Quick Guide: Features, Annotations, Dependencies, and Usage Examples

EasyExcel is an Alibaba open‑source POI plugin that simplifies Excel read/write by using a streaming SAX approach, reducing memory consumption and avoiding OOM errors.

Key advantages include annotation‑based custom operations, simple input/output interfaces, and support for cell merging.

Common annotations: @ExcelProperty: maps a field to an Excel column by name or index. @ExcelIgnore: excludes a field from read/write. @DateTimeFormat: formats date values using java.text.SimpleDateFormat. @NumberFormat: formats numeric values using java.text.DecimalFormat. @ExcelIgnoreUnannotated: only annotated fields participate in read/write.

Typical Maven dependencies:

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>2.1.4</version>
</dependency>
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.47</version>
</dependency>

A listener class extending AnalysisEventListener can collect rows during import:

public class ExcelListener extends AnalysisEventListener {
    private List<Object> datas = new ArrayList<>();
    @Override
    public void invoke(Object o, AnalysisContext ctx) {
        datas.add(o);
        // custom processing
    }
    @Override
    public void doAfterAllAnalysed(AnalysisContext ctx) {
        // optional cleanup
    }
    public List<Object> getDatas() { return datas; }
    public void setDatas(List<Object> datas) { this.datas = datas; }
}

Import example reads an uploaded file, creates the listener, and obtains a list of objects:

String filename = file.getOriginalFilename();
InputStream inputStream = file.getInputStream();
ExcelListener listener = new ExcelListener();
ExcelReader excelReader = new ExcelReader(inputStream, ExcelTypeEnum.XLS, null, listener);
excelReader.read(new Sheet(1, 0, Test.class));
List<Object> list = listener.getDatas();
if (list.size() > 1) {
    for (Object obj : list) {
        Test test = (Test) obj;
        // process each test object
    }
}

Export example writes data to the HTTP response:

String filenames = "111111";
String userAgent = request.getHeader("User-Agent");
if (userAgent.contains("MSIE") || userAgent.contains("Trident")) {
    filenames = URLEncoder.encode(filenames, "UTF-8");
} else {
    filenames = new String(filenames.getBytes("UTF-8"), "ISO-8859-1");
}
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf-8");
response.addHeader("Content-Disposition", "filename=" + filenames + ".xlsx");
EasyExcel.write(response.getOutputStream(), Test.class)
        .sheet("sheet")
        .doWrite(testList);

Local file import/export uses the same listener and ExcelReader / EasyExcel.write methods with file streams:

String filePath = "C:\\Users\\Administrator\\Desktop\\json.xlsx";
File file = new File(filePath);
InputStream is = new FileInputStream(file);
ExcelListener listener = new ExcelListener();
ExcelReader reader = new ExcelReader(is, ExcelTypeEnum.XLS, null, listener);
reader.read(new Sheet(1, 0, Test.class));
List<Object> list = listener.getDatas();
// ...process list...
String outPath = "C:\\Users\\Administrator\\Desktop\\output" + System.currentTimeMillis() + ".xlsx";
EasyExcel.write(outPath, Test.class).sheet("sheet").doWrite(testList);

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