如果仅需要文件中的部分数据，您可以使用范围下载，下载指定范围内的数据。

以下代码用于范围下载：

GetObjectRequest get = new GetObjectRequest("<bucketName>", "<objectKey>");

// 设置范围
get.setRange(new Range(0, 99)); // 下载0到99字节共100个字节，文件范围从0开始计算
// get.setRange(new Range(100, Range.INFINITE)); // 下载从100个字节到结尾

OSSAsyncTask task = oss.asyncGetObject(get, new OSSCompletedCallback<GetObjectRequest, GetObjectResult>() {
	@Override
	public void onSuccess(GetObjectRequest request, GetObjectResult result) {
		// 请求成功
		InputStream inputStream = result.getObjectContent();

		byte[] buffer = new byte[2048];
		int len;

		try {
			while ((len = inputStream.read(buffer)) != -1) {
				// 处理下载的数据
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	@Override
	public void onFailure(GetObjectRequest request, ClientException clientExcepion, ServiceException serviceException) {
		// 请求异常
		if (clientExcepion != null) {
			// 本地异常如网络异常等
			clientExcepion.printStackTrace();
		}
		if (serviceException != null) {
			// 服务异常
			Log.e("ErrorCode", serviceException.getErrorCode());
			Log.e("RequestId", serviceException.getRequestId());
			Log.e("HostId", serviceException.getHostId());
			Log.e("RawMessage", serviceException.getRawMessage());
		}
	}
});