I'm trying to use Completable in Dao class on #Insert annotated methods but when tried to compile the project, I've got this error:
error: Methods annotated with #Insert can return either void, long, Long, long[], Long[] or List<Long>.
public abstract io.reactivex.Completable insert(#org.jetbrains.annotations.NotNull()
Here my related codes:
#Insert
fun insert(kanal: Kanal): Completable
#Update
fun update(kanal: Kanal): Completable
#Delete
fun delete(kanal: Kanal): Completable
And my dependencies:
def room_version = "1.1.1"
implementation "android.arch.persistence.room:runtime:$room_version"
kapt "android.arch.persistence.room:compiler:$room_version"
implementation "android.arch.persistence.room:rxjava2:$room_version"
implementation 'io.reactivex.rxjava2:rxkotlin:2.2.0'
implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
According to this link it's supported by Room.
#Insert, #Update, and #Delete methods: Room 2.1.0 and higher supports
return values of type Completable, Single, and Maybe.
Update your room from 1.1.1 to 2.1.0 or higher and it will work.
Completable isn't working with #Insert in 1.1.1 version of Room. You have to use 2.1.0 version or higher which is only available in Android X.
Make sure to use these dependencies instead of regular android.arch.persistence.room:
def room_version = "2.2.0-alpha02"
implementation "androidx.room:room-runtime:$room_version"
kapt "androidx.room:room-compiler:$room_version" // For Java use annotationProcessor instead of kapt
implementation "androidx.room:room-rxjava2:$room_version"
testImplementation "androidx.room:room-testing:$room_version"
Here's the link that provides all of the Android X dependencies of Room.
if you dont want to update the Room's Version, you can try to make a Completable return like this:
fun insertSomthing():Completable{
return Completable.fromAction{
insert(kanal: Kanal)
}.subscribeOn(Schedulers.io())
}
above didnt work for me, here is what i used in oder fix it
def room_version = "2.2.6"
implementation "androidx.room:room-runtime:$room_version"
annotationProcessor "androidx.room:room-compiler:$room_version"
// optional - RxJava support for Room
implementation "androidx.room:room-rxjava2:$room_version"
// optional - Guava support for Room, including Optional and ListenableFuture
implementation "androidx.room:room-guava:$room_version"
// optional - Test helpers
testImplementation "androidx.room:room-testing:$room_version"
Related
I have a project with a Room database, which was working fine, and now for some reason I can't find out, it isn't anymore.
I am getting the following error when compiling:
C:\(...)\FlightDao.java:18: error: Not sure how to convert a Cursor to this method's return type (java.lang.Object).
public abstract java.lang.Object getFlightById(int id, #org.jetbrains.annotations.NotNull()
This is from a class that is generated from my Dao:
#Dao
interface FlightDao {
#Query("SELECT * FROM FlightData WHERE DELETEFLAG == 0 AND flightID = :id LIMIT 1")
suspend fun getFlightById(id: Int): FlightData?
}
Now, if I change the function to not suspend, return a Flow and get its first result, it doesnt give an error. But, according to documentation I should do it the way I did, as it is a one-shot operation.
My gradle file has these (entire file here):
apply plugin: 'kotlin-kapt'
(...)
implementation "androidx.room:room-runtime:$room_version"
kapt "androidx.room:room-compiler:$room_version"
implementation "androidx.room:room-ktx:$room_version"
and now I am at a loss for why this isn't working. Only things I find are about suspend not being compatible with LiveData, but I don't use LiveData. As far as I can tell, I did it exactly as in the documentation. Anybody has any ideas? (I did try clean and rebuild)
Kotlin version 1.7.0
Room version 2.4.2
I fixed this by switching from kapt to ksp (link)
Still not a clue why kapt didn't want to do it anymore, but meh, it works now :)
new gradle:
plugins {
id 'com.google.devtools.ksp' version '1.7.0-1.0.6'
}
(...)
dependencies {
implementation "androidx.room:room-runtime:$room_version"
ksp "androidx.room:room-compiler:$room_version"
implementation "androidx.room:room-ktx:$room_version"
(...)
}
try to delete ? in FlightData for null safety
second notice you must write query for condition with one equal sign not twice like programming
use this
#Query("SELECT * FROM FlightData WHERE DELETEFLAG = 0 AND flightID = :id LIMIT 1")
We have a plugin which defines additional properties and adds them as extension properties, like:
project.extra["copyright"] = "Copyright ..."
Then in the build scripts, I can access this like:
project.extra["copyright"]
I'd like to just write:
project.copyright
Some Gradle plugins seem to do something like this. I can access project.sourceSets or project.kotlin even though those certainly aren't in the Project interface.
Using an IDE, I can drill into those convenience methods, which then lands me in some autogenerated code, so I know it's being autogenerated somewhere, but I haven't been able to find any clues to how to get this to happen for our own plugin. The Gradle docs mention type-safe accessors which is ultimately what allowed me to phrase the question, but the docs don't say how to add new ones.
How do we get this treatment for our own plugin?
Creating DSL-like APIS is documented here: https://docs.gradle.org/current/userguide/implementing_gradle_plugins.html#modeling_dsl_like_apis.
It's pretty easy to do. Here's a quick guide, and some tips.
Define an extension.
import org.gradle.api.provider.Property
interface MyExtension {
val copyright: Property<String>
}
It looks pretty boring! What's important is that it's either be an abstract class, or an interface - this is so Gradle can create a new instance (see 'Managed types'), and this is where the Gradle magic begins.
Aside: I've used Property<String> instead of String, although both will work. I recommend using types compatible with Lazy Configuration.
Register the extension.
import org.gradle.api.*
abstract class MyPlugin : Plugin<Project> {
override fun apply(project: Project) {
val myExtension: MyExtension =
project.extensions.create("myPlugin", MyExtension::class.java)
}
}
This is the magic part. Simply by registering the extension against the project, Gradle will make the extension available and automatically generate Kotlin-DSL convenience methods.
Apply the plugin
// build.gradle.kts
plugins {
id("my-plugin")
}
myPlugin {
copyright.set("blah blah 2022")
}
Just like that, Gradle will generate Kotlin DSL accessors. Here's one of them:
// Accessorsajp3oxzka99ro52ctxwv0petb.kt
/**
* Configures the [myPlugin][MyExtension] extension.
*/
fun org.gradle.api.Project.`myPlugin`(configure: Action<MyExtension>): Unit =
(this as org.gradle.api.plugins.ExtensionAware).extensions.configure("myPlugin", configure)
Use the extension values
Going back to the Plugin definition, lets say you want to register your own task:
// a demo task
abstract class MyTask : DefaultTask() {
#get:Input
abstract val copyright: Property<String>
#TaskAction
fun run() {
println("Copyright is ${copyright.get()}")
}
}
(Note that this task, like the extension, is a 'managed type').
Now the custom task can be registered, and a default value for copyright set.
abstract class MyPlugin : Plugin<Project> {
override fun apply(project: Project) {
val myExtension: MyExtension = project.extensions.create("myPlugin", MyExtension::class.java)
project.tasks.register("myCustomTask", MyTask::class.java) {
copyright.set(myExtension.copyright)
}
}
}
It's good that both MyExtension and MyTask use Property<String> - the actual value will be evaluated lazily, and only if required.
Now if I run ./gradlew :myCustomTask, I see:
> Task :myCustomTask
Copyright is blah blah 2022
Further reading
What if you want to have multiple copyrights? Then you can create a configuration container
What if MyExtension has lots of properties and you want to provide them all to MyTask? Then you can use #Nested inputs
The extension properties can have default values.
How do you setup the Arrow dependencies for #optics annotation to actually work? No companion objects are generated for the data classes annotated with #optics.
If I'm not mistaken, this is an annotation processor, so it should be imported using kapt, however the documentation uses it as compile.
For arrow 0.10.0
apply plugin: 'kotlin-kapt'
def arrow_version = "0.10.1-SNAPSHOT"
dependencies {
implementation "io.arrow-kt:arrow-optics:$arrow_version"
implementation "io.arrow-kt:arrow-syntax:$arrow_version"
kapt "io.arrow-kt:arrow-meta:$arrow_version" // <-- this is the kapt plugin
}
then:
#optics data class Street(val number: Int, val name: String) {
companion object {} // <-- this is required
}
Everything is explained in the documentation, I don't know how I missed it
https://arrow-kt.io/docs/
I use the lib jackson-module-kotlin to parse string of json into object.
My issue is when I parse a string into an enum , and when I launch with intellij, I have this stack trace:
Caused by: kotlin.reflect.jvm.internal.KotlinReflectionInternalError:
Reflection on built-in Kotlin types is not yet fully supported. No
metadata found for public final val name: kotlin.String defined in
kotlin.Enum[DeserializedPropertyDescriptor#212b316a]
I don't have this issue when I launch with maven.
I use kotlin 1.1.51, with intellij kotlin plugin 1.2.0-release-IJ2017.3-1, I target a JVM 1.8, and i use jackson-module-kotlin version 2.8.7
what should I do?
enum class CType { DEAL, FILE }
data class Code(val code: String, val type: CType)
fun testDeserialization() {
val mapper = jacksonObjectMapper()
// following line throws an exception:
mapper.readValue("""{"code":"A","type":"DEAL"}""", Code::class.java)
}
The only way I got it working is by adding additional #JvmStatic annotation. I had mapper.registerModule(new KotlinModule()); and all, nothing worked but this:
package nc.features.algo.model
import com.fasterxml.jackson.annotation.JsonCreator
import com.fasterxml.jackson.annotation.JsonValue
enum class LHStatus (
#get:JsonValue val code: Int
) {
LH_POS_OVU_WAITING(1),
LH_NEG_OVU_WAITING(2),
;
companion object {
#JsonCreator
#JvmStatic
fun deser(code: Int?): LHStatus? {
if (code == null) return null
for (i in values()) {
if (i.code == code) return i
}
return null
}
}
}
You have to do a few things.
Update Jackson dependencies to the latest version (right now, 2.9.4).
Update Kotlin version to a version equal or greater than 1.3.0.
Be sure to add the following dependencies to your build.gradle:
implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
implementation "com.fasterxml.jackson.module:jackson-module-kotlin:$jackson_version"
... then you call registerKotlinModule() on your Jackson ObjectMapper and the code of your enum should be just like this:
enum class CType(#get:JsonValue val value: String) {
DEAL("deal"),
FILE("file");
companion object {
#JsonCreator
fun fromString(value: String): CType? {
for (type in CType.values()) {
if (type.name.equals(value, true)) {
return gender
}
}
return null
}
}
}
Intellij is most likely using the kotlin compiler version 1.2.0 (from the plugin) and it doesn't seem to support reflection properly.
I suggest you do one of the following:
Upgrade your kotlin version in maven and the intellij kotlin plugin to newer versions (e.g. 1.2.30). If you do that, you also have to update jackson-module-kotlin to >= 1.9, since there is an incompatibility with kotlin 1.2 (see here).
Set the kotlin compiler version to 1.1 in Intellij Idea settings.
It is generally a good idea to use the same version of kotlin in Intellij Idea and maven/gradle.
You need to use the Kotlin module for Jackson that is compatible with Kotlin 1.2.x, this includes minimally these three versions of the module:
2.9.4.1 (works with any 2.9.x of Jackson, but best to use most recent)
2.8.11.1 (for Jackson 2.8.x)
2.7.9.1 (for Jackson 2.7.x)
Otherwise, you will run into a problem with library mismatches.
The jackson-module-kotlin homepage lists these as the current versions, but they are likely to change and you can check the various Maven repository search engines to see which library versions are available and which dependencies they have on Kotlin to find matching versions.
Also note you can import the extensions for the ObjectMapper class and use reified types, so instead of:
val something = mapper.readValue("""{"code":"A","type":"DEAL"}""", Code::class.java)
you would have:
val something: Code = mapper.readValue("""{"code":"A","type":"DEAL"}""")
or alternatively:
val something = mapper.readValue<Code>("""{"code":"A","type":"DEAL"}""")
It is usually bad to use the erased type (i.e. Whatever::class.java) since this does not work for anything with generic type parameters, and using reified types also works nicely when deserializing into collections.
I am using #parcelize for gson
Here is my class
#Parcelize
data class CommunityModel(#SerializedName("post") val post: PostModel,
#SerializedName("is_liked") val isLiked: Boolean,
#SerializedName("post_like") val postLike: QuestionModel,
#SerializedName("polling_options") val pollingOptions: List<PollingModel>,
#SerializedName("post_polled") val postPolled: Boolean) : Parcelable
I got error Unable to invoke no-args constructor for class. Register an InstanceCreator with Gson for this type may fix this problem..
But this error only presents on older android versions (below 5.0)
I tried implementing default constructor :
constructor: this(PostModel(), true, QuestionModel(), emptyList(), true)
But it gave me java.lang.VerifyError instead
I am using retrofit2 with rxjava2 and gson converter Version 2.3
My kotlin version is 1.1.51
Is it known bug? Or did I do something wrong?
No-arg compiler plugin
The no-arg compiler plugin generates an additional zero-argument constructor for classes with a specific annotation.
The generated constructor is synthetic so it can’t be directly called from Java or Kotlin, but it can be called using reflection.
This allows the Java Persistence API (JPA) to instantiate the data class although it doesn't have the zero-parameter constructor from Kotlin or Java point of view (see the description of kotlin-jpa plugin below).
Using in Gradle
The usage is pretty similar to all-open.
Add the plugin and specify the list of annotations that must lead to generating a no-arg constructor for the annotated classes.
buildscript {
dependencies {
classpath "org.jetbrains.kotlin:kotlin-noarg:$kotlin_version"
}
}
apply plugin: "kotlin-noarg"
Source https://kotlinlang.org/docs/reference/compiler-plugins.html