使用Apache POI在.xls中行的前n列应用样式

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;

Workbook workbook = new HSSFWorkbook();

Sheet sheet = workbook.createSheet("Sheet1");

CellStyle style = workbook.createCellStyle();

Font font = workbook.createFont();
font.setBold(true);
style.setFont(font);
style.setFillForegroundColor(IndexedColors.YELLOW.getIndex());
style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
style.setBorderBottom(BorderStyle.THIN);
style.setBorderTop(BorderStyle.THIN);
style.setBorderLeft(BorderStyle.THIN);
style.setBorderRight(BorderStyle.THIN);

int n = 5; // 前n列
for (Row row : sheet) {
    for (int i = 0; i < n; i++) {
        Cell cell = row.createCell(i);
        cell.setCellStyle(style);
    }
}

FileOutputStream fileOut = new FileOutputStream("workbook.xls");
workbook.write(fileOut);
fileOut.close();