用java写一个到处excel工具类

以下是一个Java实现的导出Excel工具类的示例：

import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExcelExportUtil {

    public static void exportToExcel(List<Object[]> data, String[] headers, String sheetName, String fileName) {

        Workbook workbook = new XSSFWorkbook();

        Sheet sheet = workbook.createSheet(sheetName);

        int rowNumber = 0;

        Row headerRow = sheet.createRow(rowNumber++);

        for (int i = 0; i < headers.length; i++) {
            Cell cell = headerRow.createCell(i);
            cell.setCellValue(headers[i]);
        }

        for (Object[] rowData : data) {
            Row row = sheet.createRow(rowNumber++);
            for (int i = 0; i < rowData.length; i++) {
                Cell cell = row.createCell(i);
                cell.setCellValue(rowData[i].toString());
            }
        }

        try {
            FileOutputStream outputStream = new FileOutputStream(fileName);
            workbook.write(outputStream);
            workbook.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

该工具类使用了Apache POI库，可以将数据导出到Excel文件中。使用示例：

public class Example {

    public static void main(String[] args) {

        List<Object[]> data = new ArrayList<>();

        data.add(new Object[] { "John", "Doe", "Male", 30 });
        data.add(new Object[] { "Jane", "Doe", "Female", 25 });
        data.add(new Object[] { "Bob", "Smith", "Male", 45 });

        String[] headers = { "First Name", "Last Name", "Gender", "Age" };

        ExcelExportUtil.exportToExcel(data, headers, "Sheet1", "example.xlsx");
    }
}

该示例将一个包含3个人员信息的列表导出到名为"example.xlsx"的Excel文件中。