I am loading model in apache jena using function FileManager.get().loadModel(url).And I also know that there may be some URLs in HTTP Response Link Header .I want to load model also from the links(URLs) in link header.How to do that ? Is there any inbuilt fuctionality to get access to header and process link header in Response header?
FileManager.get().loadModel(url) packages up reading a URL and parsing the results into a model. It is packing up a common thing to do; it is not claiming to be comprehensive. It is quite an old interface.
If you wanted detailed control over the HTTP handling, see if HttpOp (a lower level) mechanism helps, otherwise do the handling in the application and hand the input stream for the response directly to the parser.
You may also find it useful to look at the code in RDFDataMgr.process for help with content negotiation.
I don't think that this is supported by Jena. I don't see any reason in doing so. The HTTP request is done to get the data and maybe also to get the response type. If you want to get the URLs in some header fields, why not simply use plain old Java:
URL url = new URL("http://your_ontology.owl");
URLConnection conn = url.openConnection();
Map<String, List<String>> map = conn.getHeaderFields();
Say I have this HTML:
<img src="http://example.com/pic"/>
What I would like to do is have example.com/pic map to an AWS API Gateway endpoint.
That endpoint would then call a lambda function.
That lambda function would read a random image from an s3 bucket and return it.
So my aim is to use a STANDARD HTML image tag and end up with an image from an s3 bucket but going via some decision code in the lambda to decide the image to return.
I know you can use s3 to serve static content directly (hence the lambda to make the decision about what image). I also know I could do stuff in the lambda like b64 encode the response and then handle it on the client but I am aiming to use the standard HTML IMG tag.
Is this possible?
I've tried using the ResponseStreamHandler (Java SDK) for the lambda and returning the byte array of the image and also added the API gateway config to not map the output to JSON, but nothing seems to work!
It seems AWS has simplified this process, so that many answers are outdated and/or overly complicated.
This is how I got Lambda to return an image through the API Gateway, as of June 2018:
1) In API Gateway, enable Use Lambda Proxy integration for your API. (This setting is located on the Integration Request section, where you had set the type to Lambda.)
2) In API Gateway, select your API and click Settings. In Binary Media Types add */*. (Note: I tried adding simply 'image/jpeg', but it seems to require */* to get all of this to work)
3) Be sure to deploy your API, otherwise your changes will not be live. (In API Gateway, select your API, then Actions > Deploy API).
4) In your Lambda code, return your image in Base64 encoding (this example is C# code):
// set the Content-type header
// set to whichever image type you're returning
var headersDic = new Dictionary<string, string>();
headersDic.Add("Content-type", "image/jpeg");
// return the response object that APIGateway requires
return new APIGatewayProxyResponse
{
StatusCode = 200,
Headers = headersDic,
// return the image in Base64 encoding
Body = Convert.ToBase64String(...your image data...),
IsBase64Encoded = true
};
Done.
If you've setup your API to not require authentication, simply type your API link into your browser, and it will display the image. Or put the API link into an IMG tag. e.g. <img src="https://asdf.execute-api.us-east-1.amazonaws.com/live/myapi" />
Note: Even though in step 2 you set the Binary Media Types to */*, API Gateway will still return text if that is what your Lambda is returning.
Luckily, now AWS API Gateway supports binary data, though you also need to update your resource method through the CLI as it is not yet implemented in the Console. This is what you need to do:
In the Method Response of your method
Set Content-Type as image/jpeg in HTTP 200 Status Response
Header
In the Integration Response of your method
Set Content-Type as 'image/jpeg' in Header Mappings. Mind the quotes!
With the AWS CLI, set contentHandling attribute to CONVERT_TO_BINARYon your Integration Response
Check to entire process in this great step-by step guide: https://stackoverflow.com/a/41434295/720665
I've run in to a similar problem. As mentioned you currently can't directly return your image in binary format from your API Gateway endpoint, which would be required for the browser to display it correctly.
However, I solved this by instead having API Gateway return a 302 Redirect, pointing to the correct file in S3. You can have your Lambda function return the url to the file, which is later on mapped to the Location header in API Gateway. The browser will follow the redirect and display the image properly.
There are several ways to implement the redirect, but I did as follow:
Lambda returns an object with the target image like so:
function handler(event, context) {
context.succeed({
location: "https://[bucket-name].s3-eu-west-1.amazonaws.com/myimage.png" });
});
}
Remove the normal '200' Method Response Status from The Integration Response in API Gateway. Replace it with a '302' response status and add the 'Location' header mapped to value 'integration.response.body.location'
Add the 302 status to the Method Response as well
Just to be clear, the client does two different requests:
The first to get the HTML (including the image url).
The second to fetch the image data from the url.
In other words, the image data is not inlined in the HTML.
Based on this knowledge you can have a Lambda (behind the API gateway) as you suggest. The Lambda implementation can have some logic that determines the url to the image stored in S3. However, the Lambda returns JSON data and not HTML (there are workarounds such as return the html in a variable) which makes things trickier, especially for large HTML pages.
I suggest a slightly different approach, since just receiving an image tag will not get you far. I assume you will inline the image tag in a HTML document, probably by using JavaScript. Then you might as well let the API Gateway / Lambda request return a JSON document with the image url and let the JavaScript either update an existing image tag with the new url or generate the tag for you.
It currently isn't possible because you cannot return binary data through the AWS API Gateway.
For this to work, the lambda function would need to return the image data as binary blob, and some meta-information such as the image content type. Then, AWS API Gateway would need to be able to map this to the HTTP response. For example:-
lambda returns:
{
contentType: 'image/png',
image: "encoded binary data"
}
then API gateway would need to map contentType to the 'content-type' header of the response, and put the image data in the body of the response with the right encoding and length.
Unfortunately, it doesn't do this right now. It only maps text encodings like application/json or application/xml as the response type (it is designed for APIs after all).
You could very easily achieve this using ElasticBeanstalk where you have a lot more control over the http response.
I resolved this problem be reconsidering my design. The underlying thinking is that Lambdas are good computing units and bad file servers.
I changed
Client > APIGW > Lambda > Image
into
Client > APIGW > Lambda > SignedURL
then Client(SignedURL) > Image
Since my client was web based, everything was easier after that shift
I have WCA 3.5.0 server and I need to get documents from the site, using web crawler.
The problem is in the fact that I have to send a POST request to the site to get some data (initialy my site consists only of a form with some fields and submit button to send the request to the server). So, my POST request body should be something like that:
{"DateFrom":"2000-01-01T00:00:00","DateTo":"2030-01-01T23:59:59","Bundles":[{"Name":"the test name that i passed","Type":-1}],"Company":[],"Transaction":[],"Text":""}
I was thinking about making a a prefetch plugin for a web crawler.
But from the documentation I've found it looks like it is hardly possible:
"The first element ([0]) in the argument array that is passed to your
plug-in is an object of type PrefetchPluginArg1, which is an interface
that extends the interface PrefetchPluginArg. This is the only
argument and the only argument type that is passed to the prefetch
plug-in."
PrefetchPluginArg1 class has only getHTTPHeader(), setHTTPHeader(), getURL(), setURL(), doFetch(), setFetch(),
where:
The getHTTPHeader method returns a String that contains the all of
the content of the HTTP request header that the crawler sends so that
the crawler can download the document.
The getURL method returns the URL (in String form) of a document that
the crawler downloads. You can use this URL to decide if the document
requires additional information in the request header, such as a
cookie.
And it looks like there is no way to change request body.
So, is it realy possible to control POST request body, but not only header, and if it is so, can you please, share some information about the ways of solving this task?
My requirement is I need to pick two http headers and few json fields in request body and using those values generate a auth token using Base64 encryption and set the auth Token into request body before Jmeter makes the HTTP request to the server.
How to do this in JMeter??
I tried creating custom functions in JMeter but in the Function class current Sampler object is null.
Thanks in advance.
I believe that Beanshell PreProcessor is what you're looking for
Access request headers:
sampler.getHeaderManager().get(0); // first header
sampler.getHeaderManager().get(1); // second header
Access request body:
sampler.getArguments().getArgument(0).getValue();
Base64 Encode something:
import org.apache.jmeter.protocol.http.util.Base64Encoder;
String encoded = Base64Encoder.encode("source");
For more information on Beanshell scripting in JMeter see How to use BeanShell: JMeter's favorite built-in component guide.
In a Google App Engine for Java web app, I am trying to use the low level api to invoke an XML RPC ...After looking at the docs, I figured out the following code to connect using low level API-the reason why I want to use Low Level API is so that I can set the timeout value myself--
String mrtime="120";
java.lang.Double maxresponsetime;
maxresponsetime = Double.valueOf(mrtime).doubleValue();
HTTPRequest req= new HTTPRequest(url, HTTPMethod.GET, disallowTruncate().setDeadline(maxresponsetime));
HTTPResponse response= com.google.appengine.api.urlfetch.URLFetchServiceFactory.getURLFetchService().fetch(req);
String line="";
String resp="";
resp=new String(response.getContent(), "UTF-8");
The above code is suitable for a scenario where the remote URL is accessed by GAE...However I have to also send an XML message containing name of function as well as input parameters (these are stored in variable named 'message')... How do I send that message to the remote URL, and after that obtain the response?
You should post the call method and parameters instead of GET. The method name and parameters go as XML.
See this http://xmlrpc.scripting.com/spec.html