POI 操作Excel 整理

1.建立工作簿 (WORKBOOK)
    HSSFWorkbook wb = new HSSFWorkbook();
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
2.建立工作表（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.建立單元格(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.建立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.單元格的不通對齊方式
    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.單元格的邊框設定
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.填充和顏色設定
    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.合併單元格操作
    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.字型設定
    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檔案
    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
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
13.在EXCEL單元格中使用自動換行
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet s = wb.createSheet();
    HSSFRow r = null;
    HSSFCell c = null;
    HSSFCellStyle cs = wb.createCellStyle();
    HSSFFont f = wb.createFont();
    HSSFFont f2 = wb.createFont();
    cs = wb.createCellStyle();
    cs.setFont( f2 );
    //Word Wrap MUST be turned on
    cs.setWrapText( true );
    r = s.createRow( (short) 2 );
    r.setHeight( (short) 0x349 );
    c = r.createCell( (short) 2 );
    c.setCellType( HSSFCell.CELL_TYPE_STRING );
    c.setCellValue( "Use \n with word wrap on to create a new line" );
    c.setCellStyle( cs );
    s.setColumnWidth( (short) 2, (short) ( ( 50 * 8 ) / ( (double) 1 / 20 ) ) );
    FileOutputStream fileOut = new FileOutputStream( "workbook.xls" );
    wb.write( fileOut );
    fileOut.close();
14.數字格式自定義
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("format sheet");
    HSSFCellStyle style;
    HSSFDataFormat format = wb.createDataFormat();
    HSSFRow row;
    HSSFCell cell;
    short rowNum = 0;
    short colNum = 0;
    row = sheet.createRow(rowNum++);
    cell = row.createCell(colNum);
    cell.setCellValue(11111.25);
    style = wb.createCellStyle();
    style.setDataFormat(format.getFormat("0.0"));
    cell.setCellStyle(style);
    row = sheet.createRow(rowNum++);
    cell = row.createCell(colNum);
    cell.setCellValue(11111.25);
    style = wb.createCellStyle();
    style.setDataFormat(format.getFormat("#,##0.0000"));
    cell.setCellStyle(style);
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();
15.調整工作單位置
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("format sheet");
    HSSFPrintSetup ps = sheet.getPrintSetup();
    sheet.setAutobreaks(true);
    ps.setFitHeight((short)1);
    ps.setFitWidth((short)1);