关于Android 关于操作文件IO的相关问题

为什么总是移动文件失败！
下面是输出打印的两句路径：

 /storage/sdcard0/dcim/Camera/IMG_20151127_094856.jpg
 /storage/sdcard0/baidu/searchbox/preset/preset4.2/pic/
    /**
     * 移动至指定文件夹
     * @param path
     * @param newPath
     * @return
     */
    public static boolean updateToFolder(String path, String newPath) {
        Log.e("==path==>>>", path);
        Log.e("==path==>>>", newPath);
        File oldfile = new File(path);
        if (!oldfile.exists()) {
            return false;
        }
        File newfile = new File(newPath);
        if (!newfile.exists()) {
            return false;
        }
        int byteread = 0;
        try {
            InputStream ipStream = new FileInputStream(oldfile); // 读入原文件
            OutputStream opStream = new FileOutputStream(newfile);
            byte[] buffer = new byte[1024];
            while ((byteread = ipStream.read(buffer)) != -1) {
                opStream.write(buffer, 0, byteread);
            }
            ipStream.close();
            opStream.close();
            oldfile.delete();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }