java操作poi如何更改excel中的数据

http://www.myexception.cn/j2ee/17951.html

修改文件最后还需要通过IO流操作来保存更改，这其实是很关键的一步，你代码里面没有IO的关闭操作，导致了数据的修改没有保存
------解决方案--------------------------------------------------------
修改的只是内存中的副本，还有自己主动写文件的，如
FileOutputStream stream;
stream = new FileOutputStream(new File(fileToBeRead ));
workbook.write(stream);
stream.close();

------解决方案--------------------------------------------------------
修改完cell的值 还需要保存一下excel

Java code

package poi.excel;import org.apache.poi.poifs.filesystem.POIFSFileSystem;import org.apache.poi.hssf.usermodel.HSSFWorkbook;import org.apache.poi.hssf.usermodel.HSSFSheet;import org.apache.poi.hssf.usermodel.HSSFRow;import org.apache.poi.hssf.usermodel.HSSFCell;import org.apache.poi.xssf.usermodel.XSSFWorkbook;import org.apache.poi.xssf.usermodel.XSSFSheet;import org.apache.poi.xssf.usermodel.XSSFRow;import org.apache.poi.xssf.usermodel.XSSFCell;import java.io.*;import java.util.Date;import java.sql.Timestamp;import java.text.DecimalFormat;/** * Created by IntelliJ IDEA. * User: admin * Date: 2011-10-10 * Time: 16:10:29 * To change this template use File | Settings | File Templates. */public class UpdateExcel2003 {    /**     * 只是一个demo，这里假设修改的值是String类型     * @param exlFile     * @param sheetIndex     * @param col     * @param row     * @param value     * @throws Exception     */    public static void updateExcel(File exlFile,int sheetIndex,int col,int row,String value)throws Exception{        FileInputStream fis=new FileInputStream(exlFile);        HSSFWorkbook workbook=new HSSFWorkbook(fis);//        workbook.        HSSFSheet sheet=workbook.getSheetAt(sheetIndex);        HSSFRow r=sheet.getRow(row);        HSSFCell cell=r.getCell(col);//        int type=cell.getCellType();        String str1=cell.getStringCellValue();        //这里假设对应单元格原来的类型也是String类型        cell.setCellValue(value);        System.out.println("单元格原来值为"+str1);        System.out.println("单元格值被更新为"+value);        fis.close();//关闭文件输入流        FileOutputStream fos=new FileOutputStream(exlFile);        workbook.write(fos);        fos.close();//关闭文件输出流    }    private String getCellValue(HSSFCell cell) {        String cellValue = "";        DecimalFormat df = new DecimalFormat("#");        switch (cell.getCellType()) {            case XSSFCell.CELL_TYPE_STRING:                cellValue = cell.getRichStringCellValue().getString().trim();                break;            case XSSFCell.CELL_TYPE_NUMERIC:                cellValue = df.format(cell.getNumericCellValue()).toString();                break;            case XSSFCell.CELL_TYPE_BOOLEAN:                cellValue = String.valueOf(cell.getBooleanCellValue()).trim();                break;            case XSSFCell.CELL_TYPE_FORMULA:                cellValue = cell.getCellFormula();                break;            default:                cellValue = "";        }        return cellValue;    }    /**     * @param args     */    public static void main(String[] args) throws Exception{        // TODO Auto-generated method stub//            下面改成你自己的xls文件进行测试，2003格式的，不能2007            File file=new File("resources/excel/stuInfo.xls");         //下面尝试更改第一行第一列的单元格的值          UpdateExcel2003.updateExcel(file,0,0,0,"更改测试");    }}