POI中增加image

引用：

Images are part of the drawing support. To add an image just call createPicture() on the drawing patriarch. At the time of writing the following types are supported:

• PNG
• JPG
• DIB

It should be noted that any existing drawings may be erased once you add a image to a sheet.

    //create a new workbook
    Workbook wb = new XSSFWorkbook(); //or new HSSFWorkbook();

    //add picture data to this workbook.
    InputStream is = new FileInputStream("image1.jpeg");
    byte[] bytes = IOUtils.toByteArray(is);
    int pictureIdx = wb.addPicture(bytes, Workbook.PICTURE_TYPE_JPEG);
    is.close();

    CreationHelper helper = wb.getCreationHelper();

    //create sheet
    Sheet sheet = wb.createSheet();

    // Create the drawing patriarch.  This is the top level container for all shapes. 
    Drawing drawing = sheet.createDrawingPatriarch();

    //add a picture shape
    ClientAnchor anchor = helper.createClientAnchor();
    //set top-left corner of the picture,
    //subsequent call of Picture#resize() will operate relative to it
    anchor.setCol1(3);
    anchor.setRow1(2);
    Picture pict = drawing.createPicture(anchor, pictureIdx);

    //auto-size picture relative to its top-left corner
    pict.resize();

    //save workbook
    String file = "picture.xls";
    if(wb instanceof XSSFWorkbook) file += "x";
    FileOutputStream fileOut = new FileOutputStream(file);
    wb.write(fileOut);
    fileOut.close();
        

Reading images from a workbook:

 
    List lst = workbook.getAllPictures();
    for (Iterator it = lst.iterator(); it.hasNext(); ) {
        PictureData pict = (PictureData)it.next();
        String ext = pict.suggestFileExtension();
        byte[] data = pict.getData();
        if (ext.equals("jpeg")){
          FileOutputStream out = new FileOutputStream("pict.jpg");
          out.write(data);
          out.close();
        }
    }