JAVA http协议GET请求方式从服务器接收文件怎么做 求一小段demo代码

求一个小demo啊~各位大神，我只知道发送请求如果是返回数据就用一个 BufferedReader接受，如果返回的是一个文件要怎么接受啊。。求教~~

文件不也是通过数据流传输过来的吗？
只不过传输过来写成一个文件就可以了

public String urlCon(final String input) {
Message message = new Message();
try {
URL url = new URL(PATH + input);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        // connection.setConnectTimeout(5000);


        connection.setReadTimeout(8000);
        connection.setRequestMethod("GET");
        connection.setUseCaches(false);
        connection.setDoOutput(true);
        connection.setDoInput(true);
        OutputStream outputStream = connection.getOutputStream();
        outputStream.flush();
        connection.connect();
        connection.getResponseCode();
        InputStream in = connection.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));

        StringBuilder response = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            response.append(line);
        }
        Log.i("返回的数据是 ", response.toString());

dowmloadfile(response.toString());
return response.toString();

    } catch (MalformedURLException e1) {
        e1.printStackTrace();
    } catch (ProtocolException e1) {
        e1.printStackTrace();
    } catch (IOException e1) {
        e1.printStackTrace();
    }
    return null;
}

如果不可以指定文件名 ，那就先服务器传过来要传的文件名呗