poi常用设置

读取和重写 Workbooks
    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");
    // 写入文件
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

在单元格中换行
    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);
    //开启Word Wrap
    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();

数据格式化
    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();

使得一个Sheet适合一页
    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);
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

设置打印区域
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("Sheet1");
    wb.setPrintArea(0, "$A$1:$C$2");
    //为第一个Sheet页设置打印区域
    //也可以这样
    //wb.setPrintArea(0, 0, 1, 0, 0) ，详细参考Java doc
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

设置页脚的页数
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("format sheet");
    HSSFFooter footer = sheet.getFooter()
    footer.setRight( "Page " + HSSFFooter.page() + " of " + HSSFFooter.numPages() );
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

使用简便的函数
这些函数保存在contrib并且提供了一些使用特征功能，例如设置合并单元格的边框，不用创建新样式改变样式属性。
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet1 = wb.createSheet( "new sheet" );
    // 合并单元格
    HSSFRow row = sheet1.createRow( (short) 1 );
    HSSFRow row2 = sheet1.createRow( (short) 2 );
    HSSFCell cell = row.createCell( (short) 1 );
    cell.setCellValue( "This is a test of merging" );
    Region region = new Region( 1, (short) 1, 4, (short) 4 );
    sheet1.addMergedRegion( region );
    // 设置边框和颜色.
    final short borderMediumDashed = HSSFCellStyle.BORDER_MEDIUM_DASHED;
    HSSFRegionUtil.setBorderBottom( borderMediumDashed, region, sheet1, wb );
    HSSFRegionUtil.setBorderTop( borderMediumDashed, region, sheet1, wb );
    HSSFRegionUtil.setBorderLeft( borderMediumDashed, region, sheet1, wb );
    HSSFRegionUtil.setBorderRight( borderMediumDashed, region, sheet1, wb );
    HSSFRegionUtil.setBottomBorderColor(HSSFColor.AQUA.index, region, sheet1, wb);
    HSSFRegionUtil.setTopBorderColor(HSSFColor.AQUA.index, region, sheet1, wb);
    HSSFRegionUtil.setLeftBorderColor(HSSFColor.AQUA.index, region, sheet1, wb);
    HSSFRegionUtil.setRightBorderColor(HSSFColor.AQUA.index, region, sheet1, wb);
    // 展示HSSFCellUtil类的用法
    HSSFCellStyle style = wb.createCellStyle();
    style.setIndention((short)4);
    HSSFCellUtil.createCell(row, 8, "This is the value of the cell", style);
    HSSFCell cell2 = HSSFCellUtil.createCell( row2, 8, "This is the value of the cell");
    HSSFCellUtil.setAlignment(cell2, wb, HSSFCellStyle.ALIGN_CENTER);
    // 写入文件
    FileOutputStream fileOut = new FileOutputStream( "workbook.xls" );
    wb.write( fileOut );
    fileOut.close();

在Sheet页中上下移动行
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("row sheet");
    //创建不同的行列
    // 将6-11行移动到0-5行
    sheet.shiftRows(5, 10, -5);
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

设置一个Sheet页为被选中的
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("row sheet");
    sheet.setSelected(true);
    // 创建不同的行列。。。
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

设置放大属性
The zoom is expressed as a fraction. For example to express a zoom of 75% use 3 for the numerator and 4 for the denominator.
Zoom被明确为一个分数，例如下面的75%使用3作为分子，4作为分母。
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet1 = wb.createSheet("new sheet");
    sheet1.setZoom(3,4);   // 75%放大
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

拆分和冻结窗口
这里有你创建的两种窗口：冻结窗口和拆分窗口。
一个冻结窗口是被行和列拆分开的，可以按照如下设置创建冻结窗口。
sheet1.createFreezePane( 3, 2, 3, 2 );
前两个参数是你要用来拆分的列数和行数。后两个参数是下面窗口的可见象限，其中第三个参数是右边区域可见的左边列数，第四个参数是下面区域可见的首行。
拆分可以将区域分成四个工作区。拆分发生在像素级别而且用户可以通过拖拽到新的位置来判断。
用如下方式拆分窗口:
sheet2.createSplitPane( 2000, 2000, 0, 0, HSSFSheet.PANE_LOWER_LEFT );
The first parameter is the x position of the split. This is in 1/20th of a point. A point in this case seems to equate to a pixel. The second parameter is the y position of the split. Again in 1/20th of a point.
第一个参数是拆分的x位置。这里单位是一个点的1/20，在这种比例下点看起来是一个像素。第二个参数是拆分的y位置，也是一个点的1/20。第三、四个参数同上。最后一个参数说明当前哪个窗口有焦点，四个选择HSSFSheet.PANE_LOWER_LEFT, PANE_LOWER_RIGHT, PANE_UPPER_RIGHT or PANE_UPPER_LEFT。
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet1 = wb.createSheet("new sheet");
    HSSFSheet sheet2 = wb.createSheet("second sheet");
    HSSFSheet sheet3 = wb.createSheet("third sheet");
    HSSFSheet sheet4 = wb.createSheet("fourth sheet");
    // 冻结第一行
    sheet1.createFreezePane( 0, 1, 0, 1 );
    // 冻结第一列
    sheet2.createFreezePane( 1, 0, 1, 0 );
    // 冻结列和行
    sheet3.createFreezePane( 2, 2 );
    // 拆分窗口并且使左下方有焦点
    sheet4.createSplitPane( 2000, 2000, 0, 0, HSSFSheet.PANE_LOWER_LEFT );
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

反复的行和列（设置打印标题）
在打印输出的时候需要使用HSSFWorkbook类的setRepeatingRowsAndColumns()方法反复的设置行和列。
这个方法包含5个参数，第一个参数是Sheet页的索引（从0开始算），第二、三个参数是重写的列的范围。不使用重写功能的话可以设置-1代替。第四、五个参数是重写的行的范围。不使用重写功能的话可以设置-1代替。
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet1 = wb.createSheet("new sheet");
    HSSFSheet sheet2 = wb.createSheet("second sheet");
    // 第一个Sheet设置从0到2的列
    wb.setRepeatingRowsAndColumns(0,0,2,-1,-1);
    // 第二个Sheet设置行和列
    wb.setRepeatingRowsAndColumns(1,4,5,1,2);
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();

页眉和页脚
这是个页眉的例子，但是页脚也同样适用.
    HSSFWorkbook wb = new HSSFWorkbook();
    HSSFSheet sheet = wb.createSheet("new sheet");
    HSSFHeader header = sheet.getHeader();
    header.setCenter("Center Header");
    header.setLeft("Left Header");
    header.setRight(HSSFHeader.font("Stencil-Normal", "Italic") + HSSFHeader.fontSize((short) 16) + "Right w/ Stencil-Normal Italic font and size 16");
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();