FastExcel

What is FastExcel

Fast, Concise, Java tool for processing Excel files that solves memory overflow issues with large files.

FastExcel will always be free and open source , using the business-friendly Apache license, making it suitable for any commercial scenarios. This provides developers and enterprises with great freedom and flexibility.

We plan to introduce more new features in the future to continuously enhance user experience and tool usability. We welcome everyone to continue following the development of FastExcel. FastExcel is committed to becoming your best choice for handling Excel files.

Features

• High-performance Reading and Writing: FastExcel focuses on performance optimization, capable of efficiently handling large-scale Excel data. Compared to some traditional Excel processing libraries, it can significantly reduce memory consumption.
• Simplicity and Ease of Use: The library offers a simple and intuitive API, allowing developers to easily integrate it into projects, whether for simple Excel operations or complex data processing.
• Stream Operations: FastExcel supports stream reading, minimizing the problem of loading large amounts of data at once. This design is especially important when dealing with hundreds of thousands or even millions of rows of data.

Example

Read

Below is an example of reading an Excel document:

// Implement the ReadListener interface to set up operations for reading data
public class DemoDataListener implements ReadListener<DemoData> {
    @Override
    public void invoke(DemoData data, AnalysisContext context) {
        System.out.println("Parsed a data entry" + JSON.toJSONString(data));
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        System.out.println("All data parsed!");
    }
}

public static void main(String[] args) {
    String fileName = "demo.xlsx";
    // Read Excel file
    FastExcel.read(fileName, DemoData.class, new DemoDataListener()).sheet().doRead();
}

Write

Below is a simple example of creating an Excel document:

// Sample data class
public class DemoData {
    @ExcelProperty("String Title")
    private String string;
    @ExcelProperty("Date Title")
    private Date date;
    @ExcelProperty("Number Title")
    private Double doubleData;
    @ExcelIgnore
    private String ignore;
}

// Prepare data to write
private static List<DemoData> data() {
    List<DemoData> list = new ArrayList<>();
    for (int i = 0; i < 10; i++) {
        DemoData data = new DemoData();
        data.setString("String" + i);
        data.setDate(new Date());
        data.setDoubleData(0.56);
        list.add(data);
    }
    return list;
}

public static void main(String[] args) {
    String fileName = "demo.xlsx";
    // Create a "Template" sheet and write data
    FastExcel.write(fileName, DemoData.class).sheet("Template").doWrite(data());
}