In data class I defined the 'name' must be unique across whole mongo collection:
#Document
data class Inn(#Indexed(unique = true) val name: String,
val description: String) {
#Id
var id: String = UUID.randomUUID().toString()
var intro: String = ""
}
So in service I have to capture the unexpected exception if someone pass the same name again.
#Service
class InnService(val repository: InnRepository) {
fun create(inn: Mono<Inn>): Mono<Inn> =
repository
.create(inn)
.onErrorMap(
DuplicateKeyException::class.java,
{ err -> InnAlreadyExistedException("The inn already existed", err) }
)
}
This is OK, but what if I want to add more info to the exceptional message like "The inn named '$it.name' already existed", what should I do for transforming exception with enriched message.
Clearly, assign Mono<Inn> to a local variable at the beginning is not a good idea...
Similar situation in handler, I'd like to give client more info which derived from the customized exception, but no proper way can be found.
#Component
class InnHandler(val innService: InnService) {
fun create(req: ServerRequest): Mono<ServerResponse> {
return innService
.create(req.bodyToMono<Inn>())
.flatMap {
created(URI.create("/api/inns/${it.id}"))
.contentType(MediaType.APPLICATION_JSON_UTF8).body(it.toMono())
}
.onErrorReturn(
InnAlreadyExistedException::class.java,
badRequest().body(mapOf("code" to "SF400", "message" to t.message).toMono()).block()
)
}
}
In reactor, you aren't going to have the value you want handed to you in onErrorMap as an argument, you just get the Throwable. However, in Kotlin you can reach outside the scope of the error handler and just refer to inn directly. You don't need to change much:
fun create(inn: Mono<Inn>): Mono<Inn> =
repository
.create(inn)
.onErrorMap(
DuplicateKeyException::class.java,
{ InnAlreadyExistedException("The inn ${inn.name} already existed", it) }
)
}
Related
I have a Kotlin project with Spring, and I created a class that looks like the following:
#JsonIgnoreProperties(ignoreUnknown = true)
data class Response(
val id: String,
#JsonProperty("quantity_of_days")
val quantityOfDays: Int,
)
And my SonarCloud reports state that the quantityOfDays line is not covered by tests:
This line is accessed multiple times inside my tests, and I even created one specifically to instantiate an object of that class. However, this line is still marked as not covered.
I wonder if it has something to do with the annotation, and if so, how do I ignore or force this line to be covered?
Ok so, it was necessary to write some very specific tests to cover that:
class ResponseTest {
#Test
fun `create response from json with underline attribute`() {
val id = "123"
val quantityOfDays = 1
val response = Response(id, quantityOfDays)
val value = Mapper.objectMapper.readValue(
"""
{
"id": "$id",
"quantity_of_days": $quantityOfDays
}
""".trimIndent(), Response::class.java)
assertThat(value).isEqualTo(response)
}
#Test
fun `create response from json with camel case attribute`() {
val response = ResponseBuilder().build()
val json = Mapper.objectMapper.writeValueAsString(response)
val value = Mapper.objectMapper.readValue(json, Response::class.java)
assertThat(value).isEqualTo(response)
}
}
I am not sure if that is the best solution, maybe there is a way to make the coverage ignore that in specific, but I could not find it. But it works.
I just want to print name of every user stored in database.
I am using this repository:
#Repository
interface User: JpaSpecificationExecutor<User>, PagingAndSortingRepository<User, Long> {
#Query("from User")
fun findAllUsers(): Stream<User>
}
inside this Service:
#Service
class MyService(val user: User) {
private val log = LoggerFactory.getLogger(javaClass)
#Transactional(readOnly = true)
fun printNames() {
log.info("here")
user.findAllUsers().use { users ->
users.map { it.firstName }
}
}
}
and it prints only here in console, but no name.
It seems like map() automatically closed the stream but I don`t know why and how to workaround it. When I put inside of use{} block only log.info(users.count()) it prints number of users stored in database. So there is a user I can print.
My question is, how can I print all names from the given stream?
Kotlin's use function is just a short-hand way of executing some code (your closure function) and then call close on the receiver (in this case the Stream) once done.
What you called users is actually the Stream<User>returned by your repository, so basically your code is just calling users.map {...}. Now, the map operator is an intermediate operator, and since Java streams are lazy, they won't actually do anything until you call a terminal operator (such as .collect or .forEach).
Assuming you want to print the user, try with:
user.findAllUsers().use {
it.forEach { println(it.firstName) }
}
Full working example (without Spring data):
import java.util.stream.Stream
// simulate a repository
fun findAllUsers() = Stream.of("First", "Second", "Third")
fun printNames() {
findAllUsers().use {
it.forEach(::println)
}
}
fun main() {
printNames()
}
Prints:
First
Second
Third
I have a moshi PolymorphicJsonAdapterFactory and it works great.
.withSubtype(ColdWeather::class.java, "Cold")
.withSubtype(HotWeather::class.java, "Hot")
.withDefaultValue(//how to grab the label)
The method withDefaultValue is a great catch all, but my BE team wants me to log the actual label that comes down in order to help catch a bug that's going on on their end. As far as I can tell... in the withDefaultValue I can't grab a reference to the label which in this case the backend is sending back "Medium".
I feel like there must be a way to grab this label (but I'm missing something simple?) so I can log it and possibly propagate it in the withDefaultValue method.
I stumbled on the issue a while ago. I found it impossible to achieve with just using .withDefaultValue method. So far I did not find better solution other than .withFallbackJsonAdapter (I am using moshi version 1.12), which lets you parse the json manually in case the label is unknown to your PolymorphicJsonAdapterFactory adapter. The documentation says:
/**
* Returns a new factory that with default to {#code fallbackJsonAdapter.fromJson(reader)} upon
* decoding of unrecognized labels.
*
* <p>The {#link JsonReader} instance will not be automatically consumed, so make sure to consume
* it within your implementation of {#link JsonAdapter#fromJson(JsonReader)}
*/
public PolymorphicJsonAdapterFactory<T> withFallbackJsonAdapter(
#Nullable JsonAdapter<Object> fallbackJsonAdapter) {
return ...
}
I assume your code is somewhat like this (simplified):
interface Weather {
val type: String
}
#JsonClass(generateAdapter = true)
class ColdWeather( #Json(name = "type") override val type: String) : Weather
#JsonClass(generateAdapter = true)
class HotWeather( #Json(name = "type") override val type: String) : Weather
val weatherAdapter = PolymorphicJsonAdapterFactory.of(Weather::class.java, "type")
.withSubtype(ColdWeather::class.java, "Cold")
.withSubtype(HotWeather::class.java, "Hot")
and you receive a json similar to this:
{
"weather" : {
"type" : "Cold"
}
}
To receive an unknown label, I would do something like this:
class UnknownWeather(override val type: String) : Weather
val weatherAdapter = PolymorphicJsonAdapterFactory.of(Weather::class.java, "type")
.withSubtype(ColdWeather::class.java, "Cold")
.withSubtype(HotWeather::class.java, "Hot")
.withFallbackJsonAdapter((object : JsonAdapter<Any>() {
override fun fromJson(reader: JsonReader): UnknownWeather {
var type = ... // parse it from the reader
return UnknownWeather(type)
}
override fun toJson(writer: JsonWriter, value: Any?) {
// nothing to do
}
}))
Of course that means that you will have to dig a bit into JsonReader, but it has a fairly understandable interface, you basically iterate through the properties of the json object and extract what you need, in our case just the "type" property.
FYI, seems like more people had problem with this: https://github.com/square/moshi/issues/784
I want to cache a result of a method only when the attribute of the result contains specific values. For example
Class APIOutput(code: Int, message: String)
sealed class Response<out T : Any> : Serializable {
data class Success<out T : Any>(val data: T) : Response<T>()
data class Error(val errorText: String, val errorCode: Int) : Response<Nothing>()
}
#Cacheable(
key = "api-key",
unless = "do something here"
)
fun doApicall(uniqueId: Long): Response<APIOutput> {
//make API call
val output = callAPI(uniqueId)
return Response.Success(output)
}
In the above method, I want to cache the response only when Response.Success.data.code == (long list of codes).
Please note, in the previous line data is nothing but APIOutput object. How could I achieve it using unless or any other approach. I was thinking of writing a function that takes a doApicall method result as input and would return true or false and call that method it as unless="call a method". But I'm not sure how to do it. Any help is highly appreciated.
You can specify an expression to be evaluated in unless using SpEL. The returned value is available as result so you can do something like -
#Cacheable(
key = "api-key",
unless = "#result!=null or #result.success.data.code!=200"
)
fun doApicall(uniqueId: Long): Response<APIOutput> {
//make API call
val output = callAPI(uniqueId)
return Response.Success(output)
}
You can even use Regex in SpEL and can create custom Expression parsers if the existing functionality is not enough for your usecase.
Thanks Yatharth and John! Below is the condition that worked for me. resultcodes in the below expression is a list
#Cacheable(
key = "api-key",
unless = "!(#result instanceof T(com.abc.Response\$Success))
or (#result instanceof T(com.abc.Response\$Success)
and !(T(com.abc.APIStatus).resultCodes.contains(#result.data.code)))"
)
fun doApicall(uniqueId: Long): Response<APIOutput> {
//make API call
val output = callAPI(uniqueId)
return Response.Success(output)
}
The problem's pretty straightforward. I have a couple of events that derive from the same interface, and I'd like to deserialize them to their propper super-class.
I know how to do that with an object mapper, but using my own mapper would mean letting Spring-Boot parse the #RequestBody as a String and then doing it myself, which isn't the worlds end, but I can't help but suspect that Spring provides proper tools to handle this kind of situation. Trouble is, I can't seem to find them.
Here's a bit of sample code:
example event:
interface YellowOpsEvent {
val user: String
val partner: String
val subject: String
val change: NatureOfChange
}
data class StatusChangedEvent(override val user: String,
override val partner: String,
override val subject: String,
val before: String,
val after: String): YellowOpsEvent {
override val change = NatureOfChange.Changed
}
controller:
#PostMapping("/event")
fun writeEvent(#RequestBody event: YellowOpsEvent) { // < I expect this not to throw an exception
val bugme = event is StatusChangedEvent // < I expect this to return true if I send the proper event data.
}
Just to clarify, I perfectly understand why this doesn't work out of the box. The trouble is, I can't find out what I need to do to make it work.
The link in pL4Gu33's comment lead me in the right direction, but it took some additional searching and fiddling, plucking information from here and there to arrive at the solution that would finally work, so I'm summarising it here for completeness.
The trouble is that you'll need two annotations, one on the interface and one on the implementing classes, the combined use of which seems somewhat ill-documented.
First, on the interface, add this annotation. Contrary to some tutorials you will find, no further annotation of the interface is required:
#JsonTypeInfo(use=JsonTypeInfo.Id.CLASS, include=JsonTypeInfo.As.PROPERTY, property="#class")
interface YellowOpsEvent {
val user: String
val partner: String
val subject: String
val change: NatureOfChange
}
According to some documentation, this alone should be enough for propper deserialisation. The spring-boot controller, however, will throw an exception because the passed root name does not match the class it was expecting.
// the above will throw an exception when the serialization product is sent to this controller:
#PostMapping("/event")
fun writeEvent(#RequestBody event: YellowOpsEvent) { // < I expect this not to throw an exception
val bugme = event is StatusChangedEvent // < I expect this to return true if I send the proper event data.
}
To fix that, add the #JsonRootName annotation to any implementing classes, with the interface's name. Most documentation of this annotation don't use it for this, instead just for renaming the type, and even when it's mentioned in the linked question in the context of polymorphism, it wrongly uses its own name. This is what it needs to look like:
#JsonRootName("YellowOpsEvent")
data class StatusChangedEvent(override val user: String,
override val partner: String,
override val subject: String,
val before: String,
val after: String): YellowOpsEvent {
override val change = NatureOfChange.Changed
}
Now it works! :)