JsonProperty names are not being respected on Jackson I would like to have custom names when writing my object but it's not printing what I have defined in annotation @JsonProperty: data class Banking( @JsonProperty("personita_id") val clientId: String?, @JsonProperty("contita_id") val accountId: String? ) val mapper = ObjectMapper() val xpto = mapper.writeValueAsString(Banking("mammamia", "miaccuenta")) xpto prints: {"clientId": "mammamia", "accountId": "miaccuenta"} What is missing in my code?

TabLayout with ViewPager2 - notifyItemChanged moves automatically to first tab I have an issue with the ViewPager2 and the TabLayout. When I call the notifyItemChanged(adapter.currentItem) the Screen always moves to the first page. Is there any chance to avoid this behaviour? Thanks in advance! Squiso

Modify the address in address bar of browser I have a web application. A User can navigate in it with several urls etc. Imagine it like yahoo.com with several links etc. you click on a link and land on another page of yahoo. Eg. once you land on the home page of yahoo and click on news you will land on a page of yahoo news with a url like - https://news.yahoo.com/ in address bar of the chrome. Now what i want is to replace this url with something gibberish say -...

Kotlin enum type where child is interchangeable with parent I have a class Transaction with subclasses Income and Expense which have a property category. Incomes and expenses have distinct categories, i.e. an IncomeCategory and ExpenseCategory. I need a list of both incomes and expenses, so I create a list of Transactions. But I need to also access their category, so Transaction also needs a category property. Since the values a category can take on is finite, enums or sealed classes would be very practical. But I need something where the supertype is...

Kotlin - pattern to convert 2 objects into another I need to convert two objects into another one and use the new object into http request. I have read about builders and converters pattern but I'm not sure if it's right or the most elegant option because my new object is kinda large and have a damn nested structure. For now, I'm creating new object in my code and it's strange: val client = customerContextClient.getClient(contextId, clientId) val address = client.addresses!!.find { a -> a.principal } val person = Person(...

Kotlin how to create default object when find returns null What is the "kotlin-way" to create a default object if find function returns null? val address = this.addresses.find { a -> a.principal } Should I conver address to variable and use a conditional like if/else?

What is the proper approach for multi-cluster kafka consumer app? Could anyone explain or share a link for an approach of a spring app? I need to connect to several different kafka clusters, consuming messages from different topics, but all across the internet only simple single cluster examples are shared... But they don't show solutions of the real problems, such as kafka autoconfiguration using different consumer and producer factories, kafka beans & templates, modules etc. ... Could anyone give a hand? Don't know where to start from...

How to download an .apk with ktor library and kotlin? I'm using the Ktor library (io.ktorktor client android1.2.5) for downloading files. When I download an image everything is fine, but when I want to download an .apk, it doesn't work. I'm using ktor 1.2.5. This is the function that I use: suspend fun HttpClient.downloadFile(file: OutputStream, url: String): Flow { return flow { try { val response = call { url(url) method =...

How can I initialize a companion object property with a value taken from application.properties? Is it possible to initialize a property of a companion object with some value read from application.properties? I tried // @Value("\${my.property.value}") ...doesn't work val myProp: Duration by lazy { Duration.ofMinutes(@Value("\${my.property.value}")) } but IntelliJ complains: Expecting an element. Okay Duration.ofMinutes() requires an Integer not a String but how can I achieve this using a configurable value in application.properties?

Dismiss rewarded ads programmatically after user received reward I want to dismiss the ad rewardedAd after the user has received the reward. It seems that rewardedAds does not have the function, such as, dismiss or setVisibility like View. The call back in the documentation looks like this: var rewardedAd: RewardedAd? = null .... myButton.setOnClickListener { if (rewardedAd.isLoaded) { val adCallback = object: RewardedAdCallback() { ......

Show Data Fast In RecyclerView [ Android Development with Kotlin ] My application must show data from a Csv File in RecyclerView. I have everything set up and I set up also a function to read the Csv File, but I have a problem. Since the Csv File is very large ( many thousand of rows ) when I try to show all the rows in the RecyclerView, app crashes. How can avoid this? Ah, I enter the data in a Room database. This is my process : ReadFile Save it as List of List of String Create my type objects for every row and create a List Apply insertAll(input : List)...

acknowledgePurchase In-app billing coroutine I am new to android and trying to implement in-app billing the first time. I am using the google play in-app library. https://developer.android.com/google/play/billing/billing_library_overview I want to implement subscription in-app purchase in kotlin. I'm not able to resolve the issue: Suspend function 'acknowledgePurchase' should be called only from a coroutine or another...

is it possible to use the messages form proto as dto, i.e. use the message type from protobuf schema file as it was a pojo class? Context: I want to send to Kafka topic the request body sent to a Micronaut gRPC endpoint. The gRPC endpoint is an implementation of autogenerated Abstract Class from io.grpc:protoc-gen-grpc-kotlin Current approach: In order to send to kafka topic a message receive from gRPC endpoint I am converting it to a DTO, property by property. I tried used the message from proto or some of the autogenerated properties from the object working as stubs but I didn't successed. Is my approach really a...

Coroutines vs Threads? It is a known fact that coroutines are cheaper than threads. Example: In Kotlin you can successfully spin off 10K coroutines, however, you would go out of memory if you try to create 10K threads. Why are coroutines much better in performance as compared to threads? Is there a case where using threads makes more sense than a coroutine? Coroutines are often referred to as light-weight threads, what does it really mean?

Kotlin - Firebase Database - Convert DataSnapShot to Hashmap I'm retrieving a node from Database that looks like this: DataSnapshot { key = appointment, value = {timeAppointment=12:00pm, dateAppointment=12/12/1221, clientUID=Bu4sw8ouUUhDv0Ut1IKqeh8kESg2, caseManagerName=Karla Moreno, userName=Sakura Nakamura, formatAppointment=Zoom} } However, I'm only able to retrieve it as a DataSnapshot. I'd like to retrieve the values, and display them using a TextView. Is there a way to convert it into a HashMap, other than hardcoding the values into a HashMap?

Kotlin App wide change TextView Color Programatically How does one change the TextView default color throughout the entire app programmatically? Not individual textView but every TextView in all activity layouts Either getting the current theme and setting the default TextView Color, if

WebView onReceivedError detects no connection only at the beginning onCreate: var browser:WebView = findViewById(R.id.browser) browser.webViewClient = object: WebViewClient() { override fun onReceivedError(view: WebView, request: WebResourceRequest, error: WebResourceError) { super.onReceivedError(view, request, error) browser.loadUrl("file:///android_asset/error.html") } } browser.loadUrl("https://google.com") If at the beginning there is no Internet connection custom error page shows. However if google.com loads in WebView and I...

Exit code: 127 when compiling Kotlin program with Kotlin Native compiler on Debian 10 I'm brand-new to Kotlin and also a beginner in programming. $ ./kotlinc-native ~/kotlin.kt -o hello error: compilation failed: The /home/user/.konan/dependencies/clang-llvm-8.0.0-linux-x86-64/bin/clang++ command returned non-zero exit code: 127 .konan/dependencies/clang-llvm-8.0.0-linux-x86-64/bin/clang++: error while loading shared libraries: libtinfo.so.5: cannot open shared object file: No such file or directory Sorry if I'm making a very obvious mistake.

io.vertx.mysqlclient.MySQLPool.query ("").execute is never really executed and return nothing I am trying a very simple tentative to insert and select to/from MySql using vertx for the first time. It is funny to me that I can build and debug the application but I never get either ar.succeeded or failed. How to execute the insert and select bellow? Do I have to enclose somehow client.query and subscribe it? I am complete stuck. All examples on internet I see follow this approach. package com.mybank import io.vertx.kotlin.mysqlclient.mySQLConnectOptionsOf import...

Are there any concerns using an object to store data retrieved from a server? Will the Object be around for as long as the app is in the background? Does anyone know when a Kotlin Object get removed from memory and reset in Android? Should I just use a ViewModel instead?

Identity not preserve In the kotlin documentation they talk about how boxing of numbers does not necessarily preserve identity and then they give an example. I don't understand why assigning the value of 10000 is different from 100. When I change the value from 10000 to 100 it becomes true.

How execute an object which was wrapped into a reference object to be modified when captured in a closure In Kotlin, how can I get/block in order to execute the code inside of client.query? var connectOptions = mySQLConnectOptionsOf(database = "mydb", host = "127.0.0.1", password = "password1!", port = 6603, user = "root") var poolOptions = poolOptionsOf(maxSize = 5) var client = MySQLPool.pool(connectOptions, poolOptions) client.query("INSERT INTO mytable('id','name') VALUES ('2','Jimis2')").execute { ar -> if (ar.succeeded()) { var rows = ar.result()...

What are different between two ways of initial MutableLiveData in Kotlin? Both Code A and Code B init a variable MutableLiveData. In my mind _playA can be null, and _playA?.value can not be null _playB can be null, and _playB?.value can be null right? Code A private val _playA = MutableLiveData(EPlayState.STOPPED) Code B private val _playB = MutableLiveData() Both enum class EPlayState { STOPPED, PLAYING, PAUSED }

Why do I get the information Enum argument can be null in Java, but exhaustive when contains no null branch in Kotlin? Code B works well, but the Code A get the following warning prompt (It can run), why? Enum argument can be null in Java, but exhaustive when contains no null branch I think _playState.value can be null in Code B too, do I should add null branch when I use exhaustive when in Code B? Code A private val _selectAction = MutableLiveData() val selectAction: LiveData = _selectAction aHomeViewModel.selectAction.observe(mLifecycleOwner) { when(it) { //Enum argument can be null in...

How to properly implement MVP and retrofit using Kotlin I was trying to replicate the MVP that I used to do in Java but it's not working. So basically I have this structure. So the BasePresenter a BaseView is new for me because I never used it like this. The error that I'm getting is Primary constructor call expected inside of the LoginPresenter. EndPoints : interface EndPoints { @POST("Register") fun Register(LoginModel: LoginModel) : Call } NetworkUtils :...

Unable to switch Night mode Changing night mode does'nt work in my mobile (it works in emulator) night mode is set to my mobile's system mode(dark mode) Since the new android studio there is default night mode theme in the starter code I need to make a app with only Light mode I've checked many solutions where we can change the theme using AppCompatDelegate method example here, <a...

How to programmatically form a firestore query? [duplicate] I'm trying to make a firestore query dynamically/programmatically based on user input. The problem is the input could be a variable amount unknown at the time of programming. I want to create the query in such a way that it will run if the user enters one input or many search terms. My example code is in Kotlin for Android: val searchFilters = listOf( "searchField1", "searchField2", "searchField3" ) var refQuery= db.collection("myCollection") for(filterName in searchFilters) {...

Getting mixed messages about coroutines I've been trying to wrap my head around coroutines and I believe I have a fairly good understanding now, but there's still a couple things that aren't clear which I have questions about. Imagine I have the below code: lateinit var item: Int val coroutine = globalScope.launch { item = onePlusOne() } suspend fun onePlusOne(): Int { return 1+1 } When the suspend function onePlusOne is called, it doesn't start a new coroutine correct? It is still executing in the same one started by...

Inappropriate blocking method call in the Logs Excel report service (Apache-poi library on Kotlin code). Any way to solve this problem? could anyone help with inappropriate blocking method call in the below code? Especially warnings come with few rows that are shown here. Files.createDirectories(targetLocation.parent) val fileStream = FileOutputStream(targetLocation.toString()) try { workbook.write(fileStream) } catch (ex: Exception) { throw FileStorageException("Could not store file $cleanPath. Please try again!", ex) } finally { workbook.close()...

Update ViewPager Content with FirestoreRecyclerAdapter using Kotlin in FirestoreRecyclerAdapter when i click item(image) show another activity showing the same item(image) but when i add view pager in order to slider image (showing the same image not switch to next image when i slid ) kotlin in FirestoreRecyclerAdapter private inner class ProductFirestoreRecyclerAdapter(options: FirestoreRecyclerOptions) : FirestoreRecyclerAdapter(options) { override fun onBindViewHolder(productViewHolder: ProductViewHolder, position: Int, productModel: Data) {...