Get the real response time using Apache Httpclient - apache-httpclient-4.x

Question

I'm trying to determine the proper way to measure the full time taken to obtain the full response from the HTTP request. From the time the HTTP GET is sent, to the time the client gets the very last entity byte from the server.
What would be the best way to do this?
For instance, in this modified version of code borrowed from the httpclient tutorial. Would the following give me the time it took to get the entire MP4 from the server?
CloseableHttpClient httpclient = HttpClients.createDefault();
HttpGet httpget = new HttpGet("http://server_ip/video.mp4");
//Start the timer here
long start_time = System.currentTimeMillis();
CloseableHttpResponse response = httpclient.execute(httpget);
try {
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
try {
final byte[] lBytes = new byte[4096];
do{
//Consume 4KB from the entity inputStream
instream.read(lBytes);
} while(instream.read(lBytes) != -1)
//Stop the timer here
long stop_time = System.currentTimeMillis();
//Get total download time?
long mp4DownloadTime = stop_time - start_time;
}
finally {
instream.close();
}
}
}
finally {
response.close();
}
Does that make any sense? I don't quite understand how the HttpClient deals with the entity content. When running a tcpdump on the interface, I see that I get the full entity regardless of what I consume in the Java code... Any guidance would be appreciated.