I am writing one client to measure Jersey, REST based web service performance. I have written some code to measure response time and to measure number of bytes sent from the server but response.getLength() method always returning -1.
In many QA forum I read that setting client.setChunkedEncodingSize(null) will work but even after setting this, I am getting -1.
From server side, I am sending response of type XML or JSON or protobuf depending upon parameters sent by client. For all of these response types, I am getting response length as -1.
My actual request looks like below:
WebResource webResourceQuery = client.resource(requestUrl);
ClientResponse response = webResourceQuery.header("Authorization", header)
.accept(MediaType.APPLICATION_JSON)
.get(ClientResponse.class);
From server side, I am not setting content-length explicitly. Can anyone please help me in getting content-length on client side?
Whole purpose of this experiment is to measure which response type is more efficient in terms of response time and amount of data sent/received.
I ran in to the same problem: client.setChunkedEncodingSize(null); does not work.
This worked for me to actually disable chunked encoding:
client.getProperties().put(ApacheHttpClient4Config.PROPERTY_ENABLE_BUFFERING, true);
Related
I'm new to Java and found a confusing behaviour related with RestTemplate.
It happened with an API returning large body (~5MB) over a quite slow network condition. The code is like below
ResponseEntity<MyEntity[]> result = restTemplate.exchange(url, HttpMethod.GET, entity, MyEntity[].class);
And also a ClientHttpRequestInterceptor is set to log before and after the request.
The confusing thing is that the after request log is logged only a while after remote server giving the response, and the HTTP Status code can be print in the log.
But the above statement took much more time to finally receive the data. Look inside the thread stack, it was reading data from socket.
I also look inside the resttemplate class and found:
response = request.execute();
handleResponse(url, method, response);
if (responseExtractor != null) {
return responseExtractor.extractData(response);
}
It seems to extractData after the execute().
My doubt is:
How does the client side know the status code even before get all the data? It just extracts necessary fields from the top packets?
Since the server has already sent out the response, where the response data is stored during the process?
It stores the data that it receives from the underlying HTTP in memory.
Client side can know what's the status code because with HTTP you get the headers and status code first before the response body. But this doesn't matter with RestTemplate as it promises to give you an object of ResponseEntity in the end, which contains everything from the http response be it status codex headers or body.
RestTemplate is an abstraction over an HttpClient, most client's give you the option to implement callbacks for separate events like onHeadersReceived(), onStatusReceived() etc. But if you are using RestTemplate this means you don't require such fine grained control.
Is it possible to send HTTP POST request to a webserver and retrieve just headers of response or read just few bytes of the body, so the rest won't be downloaded at all (so it won't consume traffic)? If yes, how?
I know that there is a HEAD method for this, but I need to achieve it by POST method .. well, I am not sure if I need the POST method, I just need to post the data. Maybe if the webserver isn't secured well enough (it doesn't check what method it's used - it's just directly access the post data), is it possible to send "post data" by HEAD request?
There is no built-in HTTP mechanism for this, and HTTP HEAD requests do not allow content in the body. If however you are the one writing the server code then anything is possible.
If this is the case, I would suggest a URL parameter that triggers this behavior. For example:
POST /myURL - This would return the whole response
POST /myURL?body=minimal - Returns the reduced size response that you are looking for.
And you would have to code your server method to construct and return the appropriate response based on the URL parameter.
I have a client who is posting some data to our server with http POST method. Our server is resin 3.0 with java. When I send response whether data is saved or not the the content length of the response is not set. client is using curl library(php wrapper over it) and they are receiving content length as 0. When I try to submit a form through a browser to our server on the same url it works and response is shown.
I tried using Apache HttpClient to submit data through postmethod and I received content length as -1 but i did get the full response. I'm not able to understand where is the problem. Also I did some google and found that resin do some chunked encoding while sending the response. But i guess it does this also for GET method. But for GET method my client is getting the content length and is able to get the response as well. Need help with this.
"Content-Length" is a header in the response, which warns the client on how big the response will be. It is not the actual length of the stream.
You can set it's value with response.setContentLength(...); in your Servlet.
im writing a java application that sends a post request to a server and expect a json from the server. Now when i need to get the response from the server do i only need to get it from the inputStream when the http code is 200 (HTTP OK) or is there any other cases ? , example :
//...
if (urlConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
// only here try to get the response
}
//...
It depends on how the server is implemented. Check the API, if the server has one. If it's internal, ask your server guy.
Generally speaking, if your response code is either 2xx or 3xx, I would check the response anyway...
If the server your communicating with is following the spec then either 200 or 201 responses are valid to contain an entity. A 204 response is successful but has no data in the response.
See section 9.5 here: http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.5 for details of acceptable responses to a POST. Extract below:
The action performed by the POST method might not result in a resource
that can be identified by a URI. In this case, either 200 (OK) or 204
(No Content) is the appropriate response status, depending on whether
or not the response includes an entity that describes the result.
If a resource has been created on the origin server, the response
SHOULD be 201 (Created) and contain an entity which describes the
status of the request and refers to the new resource, and a Location
header (see section 14.30).
There are three things to consider:
All 2xx codes denote success of some sort. But depending on the exact code, your reading code might be different. (204 for example means success but no content.)
There are redirecting codes (3xx). These are usually automatically followed by the http client library but you can also set them not to, in which case you need to have custom code that handles these cases.
There can be valuable information returned in the stream even if you get a code that denotes an error. Whether you want to process it depends on your exact needs.
I'm an experienced Java programmer but a newbie web developer. I'm trying to put together a simple web service using the HttpServer class that ships with JDK 1.6. From the examples I've viewed, some typical code from an HttpHandler's handle method would look something like this:
Headers responseHeaders = exchange.getResponseHeaders();
responseHeaders.set("Content-Type", "text/plain");
exchange.sendResponseHeaders(200, 0);
OutputStream responseBody = exchange.getResponseBody();
responseBody.write(createMyResponseAsBytes());
responseBody.close();
My question: What happens if I send a response header to indicate success (i.e. response code 200) and perhaps begin to stream back data and then encounter an exception, which would necessitate sending an "internal server error" response code along with some error content? In other words, what action should I take given that I've already sent a partial "success" response back to the client at the point where I encounter the exception?
200 is not sent until you either flush the stream or close it.
But once it is sent, there is nothing you can do about it.
Usually it may happen only when you have a really large amount of data and you use chunking.