How to Get request body in spring cloud gateway - spring-boot

Is there a way I can extract the request body (JSON) from the spring cloud gateway?. I went through a few approaches like RequestBodyrewrite and all, but as far as I understood it is used for modifying the response body. In my case, I wanted to get the request body and do some logic there and send the data via headers to the underlying microservices. Right now I am getting the request body with the attribute "cachedRequestBodyObject" with the help of the request body predicator.
readBody(SomeClass.class, s-> true)
I don't think I am not fully making use of the request body predicator here. We would also get this as part of the getRequestBody() method but it has a data buffer as a return type, so not sure how to get the JSON details from the data buffer. Is there a way better approach to do this ?..
Thanks in Advance.

Related

Standart/common/right way to send data in API request

I'm trying to learn how to create an API (I use Laravel in the backend and Postman to send requests), but I have a basic doubt when sending data to be processed in the backend.
I see that there are several ways to send data to the backend, but I'm not sure which is the right way to do it.
For example, with Postman I have seen that the sending can be done as parameters through the URI:
www.example.com/api/v1/orders?limit=10&offset=20
I can also do it in the body of the request through the tags
form data
x-www-form-urlencoded
raw
other ...
I understand that I can make the request along with sending data in several ways. I would like to know what should be the correct, standard or optimal way to do it for usual requests such as getting a series of records with a filtering, an order or a pagination.
I would also like to know if the way of sending data should depend on the verb to be used in the request.
My main question/problem is that I would like the way users use the API to be as simple or suitable as possible for them. I'm clear that I want to always return the data (when necessary) in JSON format but I'm not clear on how it should be sent.
Please, could someone clarify these doubts (maybe a link to a page where this kind of doubts are dealt with).
Thank you very much in advance.
It depends:
GET, HEAD and DELETE don't have a request body so all parameters have to be send via URL
POST can be easily sent via form data in Laravel
For PUT/PATCH I prefer application/json because PHP sends it via php://input stream which can have some problems in Laravel sometimes
You can also combine URL parameters and the request body. Compound types (for example models) can only be send as one via request body while it might suffice to send an id via URL parameter.
I guess, nearly more important is the overall format and documentation. The format should be consistent, easy to understand and maybe standardized (for example: https://jsonapi.org/format/#crud).
Keep in mind that forms do two things by default:
Only having methods GET and POST
Only having ectypes application/x-www-form-urlencoded, multipart/form-data and text/plain
If you want to enforce something else, you have to use scripts/libraries to do this.
Nowadays, it appears that JSON content (for POST, PUT, and PATCH) is the most popular and readable. It is well recognizable and clean. Examples in the documentation are easy to read.
I would go for JSON for both, incoming parameters and the outgoing response. This regards parameters related to the business logic of your application.
At the same time, for GET, HEAD, and DELETE methods, you don't have a payload at all. For parameters related to controlling the API (i.e. not strictly related to the business logic of the application, but to the API itself) I'd go for query parameters. This applies to parameters like limit, offset, order_by, etc.
P.S. There is only one caveat related to the JSON format. If your API happens to have file parameters you may face the problem. You can still use JSON format, but in such a case, you should encode your files (e.g. using base64) and put it as string parameters of your JSON. This may be demanding for the consumers of your API ;) This will also enlarge your files and will probably force you to process these files in memory. The alternative is to use multipart/form-data as a request Content-Type - this way you can have both, the form and separate "space" for files. It's worth keeping this case in mind when you decide.

Get part of JSON response object with Spring RestTemplate

I am trying to consume this, by following the tutorial from http://spring.io/guides/gs/consuming-rest/.
And I am interested in the "feeds" part of the response only.
My question is:
Is there any other way without using the toString() method in the tutorial. As, I want to access the some parts of response body and display it on a webpage.
Please, provide me with the details of the model and controller.

Three different methods in Laravel for if the request is asking for JSON. Are they the same? Do any overlap?

So these three methods are in the Laravel docs for testing if the request is for JSON.
I basically want to return JSON for any request that is requesting JSON or AJAX.
Request::ajax()
Request::isJson()
Request::wantsJson()
Can I use any of these? Do they overlap?
Not all AJAX requests expect a JSON response, so utilizing request()->ajax() is useful where you want to determine if the request was an XmlHttpRequest or not, but the response doesn't care about JSON or not.
Not all requests that contain JSON expect a JSON response. so if you don't care about whether or not the response wants JSON back, but want to determine if JSON was sent in the request, then isJson() is useful for you.
Not all requests that want JSON responses are AJAX driven, so wantsJson is useful in the case where you want to return JSON data, but you don't care how the request came to your server.
Based on these descriptions, make assertions and choose the proper functions.
You can use Request::expectsJson(). It returns true if request is ajax or wants json.
request()->ajax() is usefull if you want to check if request is only Ajax
Request::wantsJson() is usefull if you want to check if request is only Json
Request::expectsJson() is usefull if you want to check if request is either Ajax or Wants Json

HTTP Requests in Laravel

In Laravel we use routes to deal with HTTP requests from the browser.
We can route a request to a controller, do some logic and then return a response.
Now, we can send in variables encapsulated with braces {} and the response can be anything, so it seems to me that routing through a controller means that the the properties of the different request methods (POST, GET, PUT etc.) are lost.
For example I could send a POST request with URI example/{id} then put in my routes.php file
Route::post('example/{id}','SomeController#SomeAction');
Then I could do something in my controller with the variable $id and send a response.
On the other hand I could send a GET request with URI example/{id} and alter my route to
Route::get('example/{id}','SomeController#SomeAction');
The controller would give the same response.
So, am I right in thinking it does not really matter what request method is used?
Two parts of your question I can identify on a second read-through:
Request methods are not lost. You have access to them with $request->getMethod(). So a GET request will return GET. You also have the method isMethod('GET') available to you, which you could use to get a truthy value which would enable you to return a different kind of response depending on the request type.
With regards to the way you set up your URL, what HTTP verb you use does matter if you're creating a REST-ful web service.
I won't explain away what a REST-ful web service is (you can look it up), here is a couple of points from your example:
If you're getting some data, you ought to be doing a GET request. It is the verb to represent a read from a resource. If you had to send a lot of data - and your intention is to add data, you ought to POST it instead.
The URI should be meaningful in a way that best describes the resource you are manipulating.
Together with the HTTP verb, you can infer the implied action. So if you are POSTing to example/1, I might infer that (and this is a digression, actually) that you are attempting to update record 1 from an example resource. In reality, you would perhaps use the PUT verb (which handles update).
Behind the scenes, Laravel uses a POST request due to browser limitations but treats it as a PUT request server-side.
Of course request type does matter. When you want to hide some request data against user and dont show it in url for example:
?username="Admin"&nick="admin1" then u will use POST otherwise you can use GET. When you want get some data u will use GET but when you want to send some data then you should use POST instead.

wireload / Ratatosk : How to make POST requests?

In my Cappuccino frontend I'm using Ratatosk to make queries to a RESTful JSON-based API.
When I create a new resource with
[myNewResource ensureCreated];
my backend returns the status code 201 and a Location header with the URI of the newly created resource. The response body is empty. As far as I know, that's the way a REST API should react to successful POST requests.
But upon receiving the response, Ratatosk calls
- (void)connection:(CPURLConnection)aConnection didReceiveData:(CPString)data
(in WLRemoteLink.j) and tries to decode the response body. This throws an error because the response body is empty. As a consequence, the request is repeated infinitely.
How should I go about this? Am I supposed to return the whole resource in the response body?
EDIT:
Returning the ID in the response solved the problem, like
{"id":1}
Ratatosk expects the status code 204 (no content) if the response is to be empty. Otherwise it expects the full representation of the resource which was just created (which it uses to populate server side dynamic properties locally like created_at).

Resources