I use Spring R2DBC with Webflux and calling save() and findById() like below.
public Mono<CommentDTO> create(CommentDTO commentDTO, AuthenticatedUser authenticatedUser) {
return commentRepository.save(Comment.builder()
.id(commentDTO.getId())
.content(commentDTO.getContent())
.archive(commentDTO.getArchive())
.build())
.flatMap(comment -> {
return commentRepository.findById(comment.getId()).map(CommentDTO::from);
});
}
Because I'm using join query on findById() so I can't be returned the desired data with only save().
I wonder if there is a more effective way to find data with join query after saving the data.
Or is this not a bad way?
I'd appreciate your help.
Related
I'm writing some tests using rest-assured and its Kotlin extensions to test some simple Spring MVC endpoints. I'm trying to understand how to extract values.
One endpoint returns a BookDetailsView POJO, the other returns a Page<BookDetailsView> (where Page is an interface provided by Spring for doing paging).
BookDetailsView is a really simple Kotlin data class with a single field:
data class BookDetailsView(val id: UUID)
For the single object endpoint, I have:
#Test
fun `single object`() {
val details = BookDetailsView(UUID.randomUUID())
whenever(bookDetailsService.getBookDetails(details.id)).thenReturn(details)
val result: BookDetailsView = Given {
mockMvc(mockMvc)
} When {
get("/book_details/${details.id}")
} Then {
statusCode(HttpStatus.SC_OK)
} Extract {
`as`(BookDetailsView::class.java)
}
assertEquals(details.id, result.id)
}
This works as expected, but trying to apply the same technique for the Page<BookDetailsView> runs afoul of all sorts of parsing challenges since Page is an interface, and even trying to use PageImpl isn't entirely straightforward. In the end, I don't even really care about the Page object, I just care about the nested list of POJOs inside it.
I've tried various permutations like the code below to just grab the bit I care about:
#Test
fun `extract nested`() {
val page = PageImpl(listOf(
BookDetailsView(UUID.randomUUID())
))
whenever(bookDetailsService.getBookDetailsPaged(any())).thenReturn(page)
val response = Given {
mockMvc(mockMvc)
} When {
get("/book_details")
} Then {
statusCode(HttpStatus.SC_OK)
body("content.size()", `is`(1))
body("content[0].id", equalTo(page.first().id.toString()))
} Extract {
path<List<BookDetailsView>>("content")
}
println(response[0].javaClass)
}
The final println spits out class java.util.LinkedHashMap. If instead I try to actually use the object, I get class java.util.LinkedHashMap cannot be cast to class BookDetailsView. There are lots of questions and answers related to this, and I understand it's ultimately an issue of the underlying JSON parser not knowing what to do, but I'm not clear on:
Why does the "simple" case parse without issue?
Shouldn't the type param passed to the path() function tell it what type to use?
What needs configuring to make the second case work, OR
Is there some other approach for grabbing a nested object that would make more sense?
Digging a bit into the code, it appears that the two cases may actually be using different json parsers/configurations (the former seems to stick to rest-assured JSON parsing, while the latter ends up in JsonPath's?)
I don't know kotlin but here is the thing:
path() doesn't know the Element in your List, so it'll be LinkedHashMap by default instead of BookDetailsView.class
to overcome it, you can provide TypeReference for this.
java example
List<BookDetailsView> response = ....then()
.extract().jsonPath()
.getObject("content", new TypeRef<List<BookDetailsView>>() {});
kotlin example
#Test
fun `extract nested`() {
var response = RestAssured.given().get("http://localhost:8000/req1")
.then()
.extract()
.jsonPath()
.getObject("content", object : TypeRef<List<BookDetailsView?>?>() {});
println(response)
//[{id=1}, {id=2}]
}
I'm trying to learn Spring webflux & R2DBC. The one I try is simple use case:
have a book table
create an API (/books) that provides text stream and returning Flux<Book>
I'm hoping when I hit /books once, keep my browser open, and any new data inserted to book table, it will send the new data to browser.
Scenario 2, still from book table:
have a book table
create an API (/books/count) that returning count of data in book as Mono<Long>
I'm hoping when I hit /books/count once, keep my browser open, and any new data inserted /deleted to book table, it will send the new count to browser.
But it does not works. After I isnsert new data, no data sent to any of my endpoint.
I need to hit /books or /books/count to get the updated data.
I think to do this, I need to use Server Sent Events? But how to do this in and also querying data? Most sample I got is simple SSE that sends string every certain interval.
Any sample to do this?
Here is my BookApi.java
#RestController
#RequestMapping(value = "/books")
public class BookApi {
private final BookRepository bookRepository;
public BookApi(BookRepository bookRepository) {
this.bookRepository = bookRepository;
}
#GetMapping(produces = MediaType.TEXT_EVENT_STREAM_VALUE)
public Flux<Book> getAllBooks() {
return bookRepository.findAll();
}
#GetMapping(value = "/count", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
public Mono<Long> count() {
return bookRepository.count();
}
}
BookRepository.java (R2DBC)
import org.springframework.data.r2dbc.repository.R2dbcRepository;
public interface BookRepository extends R2dbcRepository<Book, Long> {
}
Book.java
#Table("book")
#Data
#AllArgsConstructor
#NoArgsConstructor
public class Book {
#Id
private Long id;
#Column(value = "name")
private String name;
#Column(value = "author")
private String author;
}
Use a Processor or Sink to handle the Book created event.
Check my example using reactor Sinks, and read this article for the details.
Or use a tailable Mongo document.
A tailable MongoDB document can do the work automatically, check the main branch of the same repos.
My above example used the WebSocket protocol, it is easy to switch to SSE, RSocket.
Below Post would help you to achieve your first requirement
Spring WebFlux (Flux): how to publish dynamically
Let me know , if that helps you
I have an OData Controller which looks pretty standard.
[HttpGet]
[ODataRoute("GridData")]
[EnableQuery]
public async Task<IQueryable<GridData>> GetGridData(ODataQueryOptions<GridData> odataOptions)
{
var query = odataOptions.ApplyTo(_service.GetGridDataQueryable()) as IQueryable<GridData>
return query;
}
Projection looks like this :
.Select(async x =>
{
//Pretty resource heavy
x.Ownership = await _ownershipService.ComputeAsync(_currentUser));
return x;
})
.Select(t => t.Result)
.ToList();
Now the problem is that I need to actually return a GridDataDTO object from this call. There is some processing that cannot be done at the database level. The processing is pretty heavy so I would not like to add it inside the GetGridDataQueryable().Also the processing is async, and need a materialized result set to be able to apply it.
I also need to return the IQueryable in the controller to be able to benefit from $count, $select, etc .
This hooks up to a pretty complex grid with a lot of options for filtering/sorting so I would not like to remove the OData functionality.
Is there a simple way to add postprocessing here ? After the result is materialized, project it to my GridDataDTO ?
There is no need for insert/update/delete support, as this will be only used for read operations.
There is no requirement for your controller method to only pass through a query from the database, in fact your method does not need to return an IQueryable<T> result at all!
You can still benefit from OData $select, $expand and $filter operators on result sets that are not IQueryable<T>, but you lose most of the performance benefits of doing so and you have to prepare you data so that the operators can be processed, and you will have to explicitly decorate your endpoint with the [EnableQuery] attribute.
In the following example you current query is materialized into memory, after applying the query options, then we can iterate over the set and manipulate it as we need to.
In the end the same recordset, with the modified records is returned, cast as queryable to match the method signature, however the method would still function the same if the result was IEnumerable<T>
There is a strong argument that says you should return IEnumerable<T> because it conveys the correct information that the recordset has been materialized and is not deferred.
[HttpGet]
[ODataRoute("GridData")]
public async Task<IQueryable<GridDataDTO>> GetGridData(ODataQueryOptions<GridData> odataOptions)
{
// NOTE: GridDataDTO : GridData
// apply $filter, $top and $skip to the DB query
IQueryable<GridData> query = odataOptions.ApplyTo(_service.GetGridDataQueryable());
// materialize
var list = query.ToList();
// project into DTO
List<GridDataDTO> output = list.Select(async x =>
{
var o = new GridDataDTO(x);
o.Ownership = await _ownershipService.ComputeAsync(_currentUser));
}).ToList();
// return, as Queryable
return output.AsQueryable();
}
UPDATE:
When the manipulations involve projection into a new type, then to properly support OData query options the type defined in your ODataQueryOptions<> needs to be assignable from the output element type. You can do this through inheritance or with implicit cast definitions.
If an explicit cast is required (or no cast is available at all) then you will have to manually validate the ApplyTo logic, the ODataQueryOptions must be a valid type reference to match the output.
I have the following feature file:
Given def query = karate.call('classpath:query/Story/FindStoryByID.js')
And def variables = { id: "xxyy" }
And request { query: '#(query)', variables: '#(variables)' }
When method POST
Then status 200
And match response.data.FindStoryByID.id != '#null'
I am currently trying to do a beforeStep in order to write whole GraphQL request (query) of the feature to a file using karate.write.
So far I have come up with this:
#Override
public boolean beforeStep(Step step, ScenarioContext context) {
if (step.getText().trim().contains("request {")) {
System.out.println(step.getText());
}
return true;
}
This successfully triggers a print, which indicates I am poking on the right direction. The problem is that I haven't still able to figure out what should I do to access a variable (query) like the one we can do on a JS/Feature file (karate.get('query');)
I am wondering if it is even possible to achieve such feat through the execution hook like this?
Thanks a lot!
Ah found it! This do the job
context.vars.get("query"));
I have a resource API that handles an object (Product for example).
I use PUT to update this object in the database.
And I want to return just en empty Mono to the user.
There is my code :
public Mono<ServerResponse> updateProduct(ServerRequest request){
Mono<Product> productReceived = request.bodyToMono(Product.class);
Mono<Product> result = productReceived.flatMap(item -> {
doSomeThing(item);
System.out.println("Called or not called!!");
return Mono.just(productService.product);
}).subscribe();
return ok()
.contentType(APPLICATION_JSON)
.body(Mono.empty(), Product.class);
}
The problem is my method doSomeThing() and the println are not called.
NB: I use subscribe but doesn't work.
Thanks.
I had a similar issue when I was new to Webflux. In short, you can't call subscribe on the request body and asynchronously return a response because the subscription might not have enough time to read the body. You can see a full explanation of a similar issue here.
To make your code work, you should couple the response with your logic stream. It should be something like the following:
public Mono<ServerResponse> updateProduct(ServerRequest request){
return request
.bodyToMono(Product.class)
.flatMap(item -> {
doSomeThing(item);
System.out.println("Called or not called!!");
return Mono.just(productService.product);
})
.then(ServerResponse.ok().build());
}