1.創建工作簿 (WORKBOOK)
    HSSFWorkbook wb = new HSSFWorkbook();
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
2.創建工作表（SHEET）
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet1 = wb.createSheet("new sheet");
    HSSFSheet sheet2 = wb.createSheet("second sheet");
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
3.創建單元格(CELL)
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");    // Create a row and put some cells in it. Rows are 0 based.
    HSSFRow row = sheet.createRow((short)0);
    // Create a cell and put a value in it.
    HSSFCell cell = row.createCell((short)0);
    cell.setCellValue(1);    // Or do it on one line.
    row.createCell((short)1).setCellValue(1.2);
    row.createCell((short)2).setCellValue("This is a string");
    row.createCell((short)3).setCellValue(true);    // Write the output to a file
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
4.創建指定單元格式的單元格
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");    // Create a row and put some cells in it. Rows are 0 based.
    HSSFRow row = sheet.createRow((short)0);    // Create a cell and put a date value in it. The first cell is not styled
    // as a date.
    HSSFCell cell = row.createCell((short)0);
    cell.setCellValue(new Date());    // we style the second cell as a date (and time). It is important to
    // create a new cell style from the workbook otherwise you can end up
    // modifying the built in style and effecting not only this cell but other cells.
    HSSFCellStyle cellStyle = wb.createCellStyle();
    cellStyle.setDataFormat(HSSFDataFormat.getBuiltinFormat("m/d/yy h:mm"));
    cell = row.createCell((short)1);
    cell.setCellValue(new Date());
    cell.setCellStyle(cellStyle);    // Write the output to a file
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
5. 單元格的不同格式
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");
    HSSFRow row = sheet.createRow((short)2);
    row.createCell((short) 0).setCellValue(1.1);
    row.createCell((short) 1).setCellValue(new Date());
    row.createCell((short) 2).setCellValue("a string");
    row.createCell((short) 3).setCellValue(true);
    row.createCell((short) 4).setCellType(HSSFCell.CELL_TYPE_ERROR);    // Write the output to a file
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
6.單元格的不同對齊方式
    public static void main(String[] args)
            throws IOException
    {
        HSSFWorkbook wb = new HSSFWorkbook();
        HSSFSheet sheet = wb.createSheet("new sheet");
        HSSFRow row = sheet.createRow((short) 2);
        createCell(wb, row, (short) 0, HSSFCellStyle.ALIGN_CENTER);
        createCell(wb, row, (short) 1, HSSFCellStyle.ALIGN_CENTER_SELECTION);
        createCell(wb, row, (short) 2, HSSFCellStyle.ALIGN_FILL);
        createCell(wb, row, (short) 3, HSSFCellStyle.ALIGN_GENERAL);
        createCell(wb, row, (short) 4, HSSFCellStyle.ALIGN_JUSTIFY);
        createCell(wb, row, (short) 5, HSSFCellStyle.ALIGN_LEFT);
        createCell(wb, row, (short) 6, HSSFCellStyle.ALIGN_RIGHT);        // Write the output to a file
        FileOutputStream fileOut = new FileOutputStream("workbook.xls");
        wb.write(fileOut);
        fileOut.close();    }
    /**
     * Creates a cell and aligns it a certain way.
     *
     * @param wb        the workbook
     * @param row       the row to create the cell in
     * @param column    the column number to create the cell in
     * @param align     the alignment for the cell.
     */
    private static void createCell(HSSFWorkbook wb, HSSFRow row, short column, short align)
    {
        HSSFCell cell = row.createCell(column);
        cell.setCellValue("Align It");
        HSSFCellStyle cellStyle = wb.createCellStyle();
        cellStyle.setAlignment(align);
        cell.setCellStyle(cellStyle);
    }
7.單元格的邊框設置
Working with borders
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");    // Create a row and put some cells in it. Rows are 0 based.
    HSSFRow row = sheet.createRow((short) 1);    // Create a cell and put a value in it.
    HSSFCell cell = row.createCell((short) 1);
    cell.setCellValue(4);    // Style the cell with borders all around.
    HSSFCellStyle style = wb.createCellStyle();
    style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
    style.setBottomBorderColor(HSSFColor.BLACK.index);
    style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
    style.setLeftBorderColor(HSSFColor.GREEN.index);
    style.setBorderRight(HSSFCellStyle.BORDER_THIN);
    style.setRightBorderColor(HSSFColor.BLUE.index);
    style.setBorderTop(HSSFCellStyle.BORDER_MEDIUM_DASHED);
    style.setTopBorderColor(HSSFColor.BLACK.index);
    cell.setCellStyle(style);    // Write the output to a file
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
8.填充和顏色設置
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");    // Create a row and put some cells in it. Rows are 0 based.
    HSSFRow row = sheet.createRow((short) 1);    // Aqua background
    HSSFCellStyle style = wb.createCellStyle();
    style.setFillBackgroundColor(HSSFColor.AQUA.index);
    style.setFillPattern(HSSFCellStyle.BIG_SPOTS);
    HSSFCell cell = row.createCell((short) 1);
    cell.setCellValue("X");
    cell.setCellStyle(style);    // Orange "foreground", foreground being the fill foreground not the font color.
    style = wb.createCellStyle();
    style.setFillForegroundColor(HSSFColor.ORANGE.index);
    style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
    cell = row.createCell((short) 2);
    cell.setCellValue("X");
    cell.setCellStyle(style);    // Write the output to a file
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
9.合并單元格操作
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");    HSSFRow row = sheet.createRow((short) 1);
    HSSFCell cell = row.createCell((short) 1);
    cell.setCellValue("This is a test of merging");    sheet.addMergedRegion(new Region(1,(short)1,1,(short)2));    // Write the output to a file
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
10.字體設置
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");    // Create a row and put some cells in it. Rows are 0 based.
    HSSFRow row = sheet.createRow((short) 1);    // Create a new font and alter it.
    HSSFFont font = wb.createFont();
    font.setFontHeightInPoints((short)24);
    font.setFontName("Courier New");
    font.setItalic(true);
    font.setStrikeout(true);    // Fonts are set into a style so create a new one to use.
    HSSFCellStyle style = wb.createCellStyle();
    style.setFont(font);    // Create a cell and put a value in it.
    HSSFCell cell = row.createCell((short) 1);
    cell.setCellValue("This is a test of fonts");
    cell.setCellStyle(style);    // Write the output to a file
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
11.自定義顏色
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet();
    HSSFRow row = sheet.createRow((short) 0);
    HSSFCell cell = row.createCell((short) 0);
    cell.setCellValue("Default Palette");    //apply some colors from the standard palette,
    // as in the previous examples.
    //we'll use red text on a lime background    HSSFCellStyle style = wb.createCellStyle();
    style.setFillForegroundColor(HSSFColor.LIME.index);
    style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);    HSSFFont font = wb.createFont();
    font.setColor(HSSFColor.RED.index);
    style.setFont(font);    cell.setCellStyle(style);    //save with the default palette
    FileOutputStream out = new FileOutputStream("default_palette.xls");
    wb.write(out);
    out.close();    //now, let's replace RED and LIME in the palette
    // with a more attractive combination
    // (lovingly borrowed from freebsd.org)    cell.setCellValue("Modified Palette");    //creating a custom palette for the workbook
    HSSFPalette palette = wb.getCustomPalette();    //replacing the standard red with freebsd.org red
    palette.setColorAtIndex(HSSFColor.RED.index,
            (byte) 153, //RGB red (0-255)
            (byte) 0,    //RGB green
            (byte) 0     //RGB blue
    );
    //replacing lime with freebsd.org gold
    palette.setColorAtIndex(HSSFColor.LIME.index, (byte) 255, (byte) 204, (byte) 102);    //save with the modified palette
    // note that wherever we have previously used RED or LIME, the
    // new colors magically appear
    out = new FileOutputStream("modified_palette.xls");
    wb.write(out);
    out.close();
12.讀和重寫EXCEL文件
    POIFSFileSystem fs      =
            new POIFSFileSystem(new FileInputStream("workbook.xls"));
    HSSFWorkbook wb = new HSSFWorkbook(fs);
    HSSFSheet sheet = wb.getSheetAt(0);
    HSSFRow row = sheet.getRow(2);
    HSSFCell cell = row.getCell((short)3);
    if (cell == null)
        cell = row.createCell((short)3);
    cell.setCellType(HSSFCell.CELL_TYPE_STRING);
    cell.setCellValue("a test");    // Write the output to a file