JXL (jxl.jar) 讀寫 Excel (.xls) 完整實戰代碼：樣式、日期、合併、公式

寫入 Excel (含樣式、型別、合併)

WritableWorkbook wb = Workbook.createWorkbook(new FileOutputStream("out.xls"));
WritableSheet sheet = wb.createSheet("Sheet1", 0);

// 1. 樣式定義
WritableFont titleFont = new WritableFont(WritableFont.TIMES, 18, WritableFont.BOLD, true);
WritableCellFormat titleFmt = new WritableCellFormat(titleFont);
titleFmt.setAlignment(Alignment.CENTRE);

// 2. 寫入各型別
sheet.addCell(new Label(0, 0, "標題", titleFmt));           // 字串
sheet.addCell(new Number(2, 0, 3.14159, new WritableCellFormat(new NumberFormat("#.##")))); // 數字格式
sheet.addCell(new Boolean(3, 0, true));                     // 布林
sheet.addCell(new DateTime(0, 1, new Date()));              // 日期
sheet.addCell(new Label(0, 2, "紅字", new WritableCellFormat(new WritableFont(WritableFont.ARIAL, 10, WritableFont.NO_BOLD, false, UnderlineStyle.NO_UNDERLINE, Colour.RED))));

// 3. 合併儲存格 (起始列,起始行,結束列,結束行)
sheet.mergeCells(0, 0, 2, 0); // 標題跨三欄

wb.write(); wb.close();

讀取 Excel (逐列轉 List)

Workbook wb = Workbook.getWorkbook(new File("in.xls"));
Sheet sheet = wb.getSheet(0);
List rows = new ArrayList<>();
for (int i = 0; i < sheet.getRows(); i++) {
    Object[] row = new Object[sheet.getColumns()];
    for (int j = 0; j < sheet.getColumns(); j++) {
        row[j] = sheet.getCell(j, i).getContents();
    }
    rows.add(row);
}
wb.close();

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