Optimized resource management of HTTP response messages

[ok2c]

Eugen, I came across your tutorial on Java Lobby. I thought I should let you know that you could make resource management of HTTP response messages less verbose and likely more optimal.

[eugenp]

I missed the fact that EntityUtils.consume also closes the content stream, so that doesn't need to be done by hand - thanks. The problem with getting the EntityUtils.consume out of finally is that it will not always be executed this way. For example, when the response is a 200 OK, the method returns before consuming the http entity.
My thinking is - get rid of the explicit closing of the stream, but keep the consume in finally, to make sure it's executed regardless.
Hope this makes sense.
Thanks for the pull request.
Eugen.

[ok2c]

You really need only either EntityUtils#consume or HttpUriRequest#releaseConnection in the finally clause. Both methods will eventually invoke the same method of the connection manager that manages the response stream. The difference between the two is that EntityUtils#consume will attempt to read until the end of message stream in order to ensure the underlying connection could be kept alive and re-used, while HttpUriRequest#releaseConnection will just shut down the connection without further ado. Depending on how aggressive one might want to be about connection re-use it is generally sufficient to attempt to re-use the connection in the source of normal request execution while using HttpUriRequest#releaseConnection as the last safeguard for abnormal situations.

[eugenp]

That's was my understanding of consume as well - that it fully reads the stream and then it closes it. Also, it looks like a side goal of releaseConnection is to allow the request itself to be reused (which I am not doing - the request object is throw away). My only concern is - I wasn't 100% sure that release connection means the stream will be closed as well.
But, if it does and only one call is enough, wouldn't it make sense to get rid of the other (instead of having it execute only for half of the cases)?

[ok2c]

As I said either is sufficient. The choice of one depends on how conservative you want to be with connection re-use. I personally would not bother trying to salvage connections in case of an exceptional situation.