POI 엑셀(Excel)문서 처리 패키지

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

    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();                    

    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();                    

    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();                    

    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();                    

    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);    }                    

    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();                    

Sometimes, you'd like to just iterate over all the rows in a sheet, or all the cells in a row. This is possible with a simple for loop.

Luckily, this is very easy. HSSFRow defines a CellIterator inner class to handle iterating over the cells (get one with a call to row.cellIterator()), and HSSFSheet provides a rowIterator() method to give an iterator over all the rows.

(Unfortunately, due to the broken and backwards-incompatible way that Java 5 foreach loops were implemented, it isn't possible to use them on a codebase that supports Java 1.4, as POI does)

	HSSFSheet sheet = wb.getSheetAt(0);	for (Iterator rit = sheet.rowIterator(); rit.hasNext(); ) {		HSSFRow row = (HSSFRow)rit.next();		for (Iterator cit = row.cellIterator(); cit.hasNext(); ) {			HSSFCell cell = (HSSFCell)cit.next();			// Do something here		}	}				

	HSSFSheet sheet = wb.getSheetAt(0);	for (Iterator<HSSFRow> rit = (Iterator<HSSFRow>)sheet.rowIterator(); rit.hasNext(); ) {		HSSFRow row = rit.next();		for (Iterator<HSSFCell> cit = (Iterator<HSSFCell>)row.cellIterator(); cit.hasNext(); ) {			HSSFCell cell = cit.next();			// Do something here		}	}				

Sometimes, you'd like to just iterate over all the rows in a sheet, or all the cells in a row. If you are using Java 5 or later, then this is especially handy, as it'll allow the new foreach loop support to work.

Luckily, this is very easy. Both HSSFSheet and HSSFRow implement java.lang.Iterable to allow foreach loops. For HSSFRow this allows access to the CellIterator inner class to handle iterating over the cells, and for HSSFSheet gives the rowIterator() to iterator over all the rows.

	HSSFSheet sheet = wb.getSheetAt(0);	for (HSSFRow row : sheet.rowIterator()) {		for (HSSFCell cell : row.cellIterator()) {			// Do something here		}	}