FileOutputStream保存文件

//保存文件，根据传入的路径，存放在SD卡目录下
public boolean saveToPath(String title, String pageName) {

    Bitmap b = getChartBitmap();

    OutputStream stream = null;
    try {
        stream = new FileOutputStream(Environment.getExternalStorageDirectory().getPath()
                +pageName+ "/" + title + ".png");

        /*
         * Write bitmap to file using JPEG or PNG and 40% quality hint for
         * JPEG.
         */
        b.compress(CompressFormat.PNG, 40, stream);

        stream.close();
    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }

    return true;
}