Java导出excel工具类

以下是一个简单的Java导出Excel的工具类示例，使用Apache POI库：

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.CellStyle;
import org.apache.poi.ss.usermodel.IndexedColors;
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 ExcelUtil {
    
    public static void exportDataToExcel(List<MyData> dataList, String filePath) throws IOException {
        Workbook workbook = new XSSFWorkbook();
        Sheet sheet = workbook.createSheet("Data Sheet");
        createHeaderRow(sheet);
        int rowCount = 1;
        for (MyData data : dataList) {
            Row row = sheet.createRow(rowCount++);
            writeDataToRow(data, row);
        }
        autosizeColumns(sheet);
        try (FileOutputStream outputStream = new FileOutputStream(filePath)) {
            workbook.write(outputStream);
        }
    }
    
    private static void createHeaderRow(Sheet sheet) {
        Row headerRow = sheet.createRow(0);
        CellStyle headerCellStyle = sheet.getWorkbook().createCellStyle();
        headerCellStyle.setFillForegroundColor(IndexedColors.LIGHT_BLUE.getIndex());
        headerCellStyle.setFillPattern(CellStyle.SOLID_FOREGROUND);
        String[] headers = {"ID", "Name", "Age", "Gender"};
        for (int i = 0; i < headers.length; i++) {
            Cell cell = headerRow.createCell(i);
            cell.setCellValue(headers[i]);
            cell.setCellStyle(headerCellStyle);
        }
    }
    
    private static void writeDataToRow(MyData data, Row row) {
        Cell idCell = row.createCell(0);
        idCell.setCellValue(data.getId());
        Cell nameCell = row.createCell(1);
        nameCell.setCellValue(data.getName());
        Cell ageCell = row.createCell(2);
        ageCell.setCellValue(data.getAge());
        Cell genderCell = row.createCell(3);
        genderCell.setCellValue(data.getGender());
    }
    
    private static void autosizeColumns(Sheet sheet) {
        for (int i = 0; i < sheet.getRow(0).getLastCellNum(); i++) {
            sheet.autoSizeColumn(i);
        }
    }
}

在上面的代码中，我们首先创建一个XSSFWorkbook对象，然后创建一个名为“Data Sheet”的工作表。接下来，我们在工作表中创建一个标题行，并设置单元格样式。然后，我们遍历数据列表并将数据写入每一行。最后，我们自适应每列的宽度，然后将工作簿写入输出流中保存到指定路径。