我这里有加载图片的方法，你可以借鉴一下。
/**
* 加载照片
* @param patriarch 图片编辑对象
* @param wb 文档
* @param col 列号(从0开始)
* @param row 行号(从0开始)
* @param accessoryID
*/
private void loadPicture(HSSFPatriarch patriarch, HSSFWorkbook wb, short col, int row, String accessoryID) {
try{
BufferedImage bufferImg =null;
ByteArrayOutputStream byteArrayOut = new ByteArrayOutputStream();
bufferImg = ImageIO.read(Attachment.download(accessoryID));
ImageIO.write(bufferImg,"jpg",byteArrayOut);
HSSFClientAnchor anchor = new HSSFClientAnchor(0,0,1000,255,col,row,col,row);
patriarch.createPicture(anchor , wb.addPicture(byteArrayOut.toByteArray(),HSSFWorkbook.PICTURE_TYPE_JPEG)); //插入图片
byteArrayOut.close();
}catch (IOException e) {
e.printStackTrace();
}
}
