On Thursday, October 6, 2011 at 1:40 PM, Oleg Kalnichevski wrote:
> On Thu, 2011-10-06 at 13:21 -0700, David Hosier wrote:
> > Understood. The library does not support the use case of obtaining the 
> > entity of a response via the recommended usage for any response other than 
> > a 2xx.
> 
> BasicResponseHandler does not, hence, unsurprisingly, the name Basic.
> However, there is _nothing_ that prevents you from writing a custom,
> better ResponseHandler which handles response entities differently.
> While the ResponseHandler interface is indeed the recommended way of
> handling responses, the BasicResponseHandler is just its very basic
> implementation which was never meant to be used for anything else but
> the most simplistic use cases. No one in their sane mind should _ever_
> convert an HTTP response to a string in a productive application. 
> 
> >  Additionally, the javadoc for BasicResponseHandler is incorrect. 
> 
> What exactly is incorrect? If you think javadocs are not clear enough or
> specific enough I'll happily apply a patch if you submit one.
I went and looked more closely, and the issue is that I was looking at the 
class-level javadoc for BasicResponseHandler. The class-level javadoc indicates 
that the response body is read before throwing the exception on status codes 
>=300. However, the javadoc for the handleResponse() method does not indicate 
that the response body is read. The statement about reading the response body 
on >=300 really only occurs when used with HttpClient, and it's that class that 
actually does the reading. That's how I read the code at least.
> 
> Oleg
> 
> > So now that I understand better how things work, I can take action 
> > accordingly. Thanks for the responses.
> > 
> > -- David Hosier
> > 
> > On Thursday, October 6, 2011 at 11:40 AM, Oleg Kalnichevski wrote:
> > 
> > > On Thu, 2011-10-06 at 11:31 -0700, David Hosier wrote:
> > > > I'm using the DefaultHttpClient to make the call, yes. I want to use 
> > > > DefaultHttpClient with the ResponseHandler the way I am supposed to. 
> > > > However, the API does not give me the ability to get a hold of the 
> > > > Entity if the status code is 404, because it throws an Exception which 
> > > > does not contain the entity value. I need the Entity value, even if the 
> > > > call returns 404. As far as I can tell, I cannot get the information I 
> > > > need from the API the way it is designed to be used. Is that clearer? 
> > > > Is my assessment correct?
> > > 
> > > Yes, it is intentional that the exception thrown does not contain a
> > > response body, because it would involve reading the entire body content
> > > into a memory buffer.
> > > 
> > > Oleg
> > > 
> > > 
> > > > -- David Hosier
> > > > 
> > > > On Thursday, October 6, 2011 at 11:29 AM, Oleg Kalnichevski wrote:
> > > > 
> > > > > On Thu, 2011-10-06 at 10:47 -0700, David Hosier wrote:
> > > > > > I am using this to interface with some REST services. One key to a 
> > > > > > good REST service is to never let something like a 404 spit out the 
> > > > > > server's generic 404 HTML page in response to a REST request. So my 
> > > > > > service instead returns an entity with the 404 that says something 
> > > > > > like "Could not find alert 12334". I should be able to show this 
> > > > > > response entity. However, given the way the ResponseHandler works 
> > > > > > with HttpClient, this is not possible, because the entity is not 
> > > > > > part of the Exception that is thrown when the ResponseHandler 
> > > > > > encounters a 404. Without manually reading the entity after 
> > > > > > ResponseHandler throws an Exception, I would only be able to show 
> > > > > > the fields that are contained in the Exception. That means I could 
> > > > > > only show the text 'Not Found', which is hardly meaningful since 
> > > > > > the status code of 404 already tells me that.
> > > > > 
> > > > > You are using ResponseHandler to interface with some REST services
> > > > > without using DefaultHttpClient? I am sorry but it still makes no 
> > > > > sense
> > > > > to me. You might as well handle responses from that service _any_ way
> > > > > you like without using a ResponseHandler.
> > > > > 
> > > > > Oleg
> > > > > 
> > > > > > -- David Hosier
> > > > > > 
> > > > > > On Thursday, October 6, 2011 at 5:39 AM, Oleg Kalnichevski wrote:
> > > > > > 
> > > > > > > On Thu, 2011-10-06 at 02:59 -0700, David Hosier wrote:
> > > > > > > > Ok, I see what the difference is in this situation. I am not 
> > > > > > > > passing the ResponseHandler to the execute() method. I am 
> > > > > > > > actually calling handleResponse() on the ResponseHandler 
> > > > > > > > manually.
> > > > > > > 
> > > > > > > I honestly see no sense in doing so. ResponseHandler is pretty 
> > > > > > > much
> > > > > > > useless without the resource management code in 
> > > > > > > AbstractHttpClient.
> > > > > > > 
> > > > > > > What is the reason you want to invoke #handleResponse manually?
> > > > > > > 
> > > > > > > Oleg
> > > > > > > 
> > > > > > > >  The problem I have with the implementation is that I return 
> > > > > > > > error messages on error conditions. With the way this works, 
> > > > > > > > you can only get very basic information from the 
> > > > > > > > HttpResponseException. For example, on a 404, it looks like the 
> > > > > > > > Exception only contains 404 and 'Not Found'. I am able to pluck 
> > > > > > > > out the entity when invoking handleResponse() manually by 
> > > > > > > > simply consuming the entity myself, but it's not possible to 
> > > > > > > > get the entity if the ResponseHandler is passed to execute() 
> > > > > > > > and the status is not 2xx. Am I off base here or is my analysis 
> > > > > > > > correct? Would you recommend that if I really need the entity 
> > > > > > > > on a non-2xx response that I just keep manually consuming the 
> > > > > > > > entity? I'm not sure it would make sense for your library to 
> > > > > > > > attempt to consume the entity in BasicResponseHandler and try 
> > > > > > > > to add it as an
> > > > > > > >  other fi
> > > > > > > > eld to the HttpResponseException. The AbstractHttpClient code 
> > > > > > > > you linked me to would have to change if you did that.
> > > > > > > > 
> > > > > > > > -- David Hosier
> > > > > > > > 
> > > > > > > > On Thursday, October 6, 2011 at 2:30 AM, David Hosier wrote:
> > > > > > > > 
> > > > > > > > > On Thursday, October 6, 2011 at 2:22 AM, Oleg Kalnichevski 
> > > > > > > > > wrote:
> > > > > > > > > > On Wed, 2011-10-05 at 13:44 -0700, David Hosier wrote:
> > > > > > > > > > > Perhaps I'm wrong, but the code for BasicResponseHandler 
> > > > > > > > > > > in httpclient 4.1.2 does not satisfy the javadocs as 
> > > > > > > > > > > written. The javadoc states the following:
> > > > > > > > > > > 
> > > > > > > > > > > "If the response code was >= 300, the response body is 
> > > > > > > > > > > consumed and an HttpResponseException 
> > > > > > > > > > > (http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/client/HttpResponseException.html)
> > > > > > > > > > >  is thrown."
> > > > > > > > > > > 
> > > > > > > > > > > However, the code does not do that:
> > > > > > > > > > > 
> > > > > > > > > > > StatusLine statusLine = response.getStatusLine();
> > > > > > > > > > > if (statusLine.getStatusCode() >= 300) {
> > > > > > > > > > >  throw new 
> > > > > > > > > > > HttpResponseException(statusLine.getStatusCode(),
> > > > > > > > > > >  statusLine.getReasonPhrase());
> > > > > > > > > > > }
> > > > > > > > > > > 
> > > > > > > > > > > HttpEntity entity = response.getEntity();
> > > > > > > > > > > return entity == null ? null : 
> > > > > > > > > > > EntityUtils.toString(entity);
> > > > > > > > > > > 
> > > > > > > > > > > The code clearly throws the Exception without reading the 
> > > > > > > > > > > entity. So what happens is that if you get a non-2xx 
> > > > > > > > > > > response, connections are never released as can be seen 
> > > > > > > > > > > by enabling DEBUG logging for the library. Am I 
> > > > > > > > > > > misreading the code or javadocs, or is this really 
> > > > > > > > > > > broken? If I catch the Exception and then read the entity 
> > > > > > > > > > > manually like shown above, I can see the connections 
> > > > > > > > > > > being closed.
> > > > > > > > > > > 
> > > > > > > > > > > -David
> > > > > > > > > > 
> > > > > > > > > > Hi David
> > > > > > > > > > The resource management is taken care of by HttpClient [1]. 
> > > > > > > > > > I do not
> > > > > > > > > > think BasicResponseHandler is broken. The whole point of 
> > > > > > > > > > ResponseHandler
> > > > > > > > > > is to free the user from having to worry about resource 
> > > > > > > > > > management and
> > > > > > > > > > response entities.
> > > > > > > > > Interesting. Thanks for the link to the code. I can assure 
> > > > > > > > > you that in my situation however, that the connections are 
> > > > > > > > > not getting closed. I'll take a closer look at the code and 
> > > > > > > > > compare it to this linked code to see if I'm using the right 
> > > > > > > > > stuff. My assumption at this point then is that I'm just 
> > > > > > > > > doing something wrong. Thanks. 
> > > > > > > > > > 
> > > > > > > > > > Oleg
> > > > > > > > > > 
> > > > > > > > > > [1]
> > > > > > > > > > http://hc.apache.org/httpcomponents-client-ga/httpclient/xref/org/apache/http/impl/client/AbstractHttpClient.html#930
> > > > > > > > > > 
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