What is the basic core difference between:
kotlin-kapt
annotationProcessor()
Also, what's the working behavior of these in Kotlin/Java?
I researched a lot about this topic but I'm a little bit confused. So, I need to learn more to clear my concepts.
kapt: Default annotation processor for Kotlin projects, useful to reference generated code at compile time in a kotlin project. In order to use it you should use the kotlin-kapt plugin. It also takes care of java classes
plugins {
kotlin("kapt") version "1.7.10"
}
and the related dependency:
dependencies {
kapt("groupId:artifactId:version")
}
annotationProcessor: gradle directive to specify your own annotationProcessor or a third party one. For example, in the old android projects was common to use Butterknife library that has its own annotation processor:
dependencies {
annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.3'
}
In general, an annotation processor is useful to generate code automatically from annotations (for butternife, for example #BindView) and this is true both for kapt and for a random third-party annotation processor.
Android studio gave the error:
Execution failed for task ':app:kaptDebugKotlin'.
> A failure occurred while executing org.jetbrains.kotlin.gradle.internal.KaptExecution
> java.lang.reflect.InvocationTargetException (no error message)
I want to add in my project Kotlin Coroutines and use it with Room database. But after added all libraries I got this error. This is all information from the compiler.
I have identified, This is because of the annotation #Database. If I removed this annotation, the error don't appear, but Room is not working too.
My gradle file:
apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'
//apply plugin: 'androidx.navigation.safeargs'
kotlin {
experimental {
coroutines 'enable'
}
}
android {
compileSdkVersion 29
defaultConfig {
applicationId "com.bestcred.coursetthree"
minSdkVersion 21
targetSdkVersion 29
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
//vectorDrawables.useSupportLibrary = true
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
// Enables data binding.
buildFeatures {
dataBinding true
}
}
dependencies {
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
// Support libraries
implementation "androidx.appcompat:appcompat:1.2.0"
implementation 'com.google.android.material:material:1.2.0'
implementation "androidx.fragment:fragment:1.2.5"
implementation "androidx.constraintlayout:constraintlayout:2.0.0"
// Android KTX
implementation 'androidx.core:core-ktx:1.3.1'
// Room and Lifecycle dependencies
implementation "androidx.room:room-runtime:$room_version"
implementation 'androidx.legacy:legacy-support-v4:1.0.0'
kapt "android.arch.persistence.room:compiler:$room_version"
// Kotlin Extensions and Coroutines support for Room
implementation "androidx.room:room-ktx:$room_version"
// Coroutines
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutine_version"
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutine_version"
}
kotlin_version = "1.4.0"
room_version = "2.2.5"
coroutine_version = '1.3.9'
I update Room version and add Kotlin Coroutines. What's problem?
Android Studio's UI was just hiding the error...
when the error occurred, it highlighted the item in the list view, and showed an unhelpful message in the terminal view.
to find the real error, select the root item in the list view so that Android Studio would display the whole build output in the terminal view, then scroll to find error.
I develop in Apple Silicon Macbook M1.
use room_version 2.2.4,
fails in 2.2.5
def room_version = "2.2.4"
implementation "androidx.room:room-runtime:$room_version"
kapt "androidx.room:room-compiler:$room_version"
implementation "androidx.room:room-ktx:$room_version"
testImplementation "androidx.room:room-testing:$room_version"
You need change:
kapt "android.arch.persistence.room:compiler:$room_version"
to
kapt "androidx.room:room-compiler:$room_version"
This exception occurs when you have done some mistake on Room database or Doa or entity class
for example I had done mistakes in the entity class
I had made the autogenerated field of Entity class val instead of var
I had put delete annotation on two functions with a different name but they were deleting the same data
so I would suggest to check the entity,dao or database class carefully if you imported the right dependency.
#Entity(tableName = "user_table")
data class User(
val firstName: String,
val lastName: String,
val age: Int
) {
#PrimaryKey(autoGenerate = true)
var id: Int = 0 //**do not made it val**
}
I'm currently having this error on m1 Mac with Room version 2.3.0.
I fixed it by changing it to 2.4.0-alpha04.
This has been reported to Google (issue tracker).
Today I faced this error. In my case, I have both java 11 and java 16 installed in my laptop, and java 16 was the default. But the gradle in my project uses java 11 to build it. So when I invoked
$ gradle build
from my terminal, it would use java 16 and so the build failed. I know, the proper solution is to make my code compatible with java 16, but for now, I am explicitly telling gradle to use java 11 using the following command:
$ gradle build -Dorg.gradle.java.home=/usr/lib/jvm/java-11-openjdk-amd64 # warning: use te path to your java 11
Since it is a large command, I saved it in a script file and so simply running the script solves the problem for me.
Try to add this in your app/build.gradle file and run the program again. It helped me to find the real cause of the issue.
kapt {
correctErrorTypes true
}
I might be late but only following solution worked for me.
Open gradle.properties file in Android studio.
Add following lines:
kapt.use.worker.api=false
kapt.incremental.apt=false
Clean & Re-build the application.
Done
I had faced the same issue. The problem was because I was using coroutine suspend functions in the Room DAO and had not implemented the necessary implementations. The following worked for me, try replacing the existing Room dependencies with:
def room_version = "2.2.5" //Use latest version
"androidx.room:room-runtime:$room_version"
"androidx.room:room-compiler:$room_version"
"androidx.room:room-ktx:$room_version"
If the above does not work, go to Analyze->Inspect Code and check for code-breaking warnings or errors(Specifically in Room)
I had to update Room to latest 2.2.5 and it has resolved the issue.
This issue occurred on package renaming
I've dragged and dropped all files from one package to other.
Objectbox it created the cursor files and entity files (auto-generated files)
Had to delete them and re-built.
It ate up 1 hour straight -_-
Make sure Gradle JDK is set to the correct version (it was set to JDK 8 even though I've been using JDK 11 for quite some time now).
Open Preferences -> Builds Tools -> Gradle -> Set Gradle JDK.
Image of Gradle JDK in Android Studio
You have to use gradlew assemble --stacktrace in terminal to get more detailed error log.
If you're on Mac, then run this instead ./gradlew assemble --stacktrace
Make sure to include all entities inside the Database annotation.
I updated the Room version from 2.2.5 to 2.3.0 or to current version in the build.gradle script file. The build was successful.
Update the gradle JDK to java 11.
There's an error that is in your files, but the editor cannot show you because the file is closed and hasn't been analysed.
This mostly occurs when you amend some data classes/POJOs and your app has several layers that depend on each other.
As the dependency goes up, some functions cannot infer data types and returns this kind of an error.
Command+Click on the modified data classes and see where
they are being used, you may possibly find the error there.
Open your files one by one, you don't have to hang on
there and wait for the editor to finish analysing(If your editor
takes some time to), as the editor analyses, the errors will be
displayed and you can fix them and have a successful build.
There's the option of Code -> Analyse code on android studio but sometimes it doesn't work as expected, you may try this - just incase.
For Apple M1 processor :
Kindly update the room version to the latest one.
implementation "androidx.room:room-runtime:2.4.3"
implementation "androidx.room:room-rxjava2:2.4.3"
kapt "androidx.room:room-compiler:2.4.3"
In my case I gave the argument type of insertAll() and delete() function as Entity ofyour database, the Error Solved
#Dao
interface NotesDao {
#Insert
fun insertAll(INotesEntity: NotesEntity) // argument type should be entity of your database
#Delete
fun delete(DNotesEntity: NotesEntity) // argument type should be entity of your database
}
While it's rather strange, I had onDestory defined two times in one file and caused this error when trying to run the app, once i deleted one of them everything worked normally.
When I faced this issue, it was about data-binding in an XML file.
I deleted a code using backticks `` and changed it into string interpolation.
suspend not being compatible with LiveData, So delete suspend from your DAO function that returns LiveData
The only thing that worked for me -
In gradle.properties replace the following line -
org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
by
org.gradle.jvmargs=--illegal-access=permit
I added a new Retrofit interface to my project containing a couple of Endpoints annotated with the #GET and #HEADERS annotations, after Injecting said interface to a repository class using the #Inject annotation in the constructor of said class, Android Studio throws this error:
NonExistentClass cannot be converted to Annotation
After taking a look at the generated Java code, it replaces the #GET and #HEADERS annotations with this:
#error.NonExistentClass()
I've already tried the following:
Using annotatioProcessor instead of kapt
Setting jetifier.enabled to false in gradle.properties
Setting generateStubs to true in my build.gradle file
Setting correctErrorTypes to true in my build.gradle file
Im using:
Android Studio 3.3
Kotlin 1.3.11
Dagger 2.21
Retrofit 2.3.0
Kotlin
Kapt
could it be some dagger scope issue? or Retrofit / dagger not fully compatible with the new versions of the Kapt plugin?
Luckily this question led me to figure out my issue. While moving around classes from an app module into a library, I was referencing an annotation class which only existed in a debug folder. So debug builds were fine, but calls to gradlew install failed when generating release files.
The error for me was very explicit although it took me a long time to realize - the generated file had literally replaced the missing annotation with #error.NonExistentClass()
Moving the file into the main src set meant both debug and release builds could see the class. What took me a while to figure out was that I assumed this was a Dagger issue being masked by kapt, but really it was just a regular old Dagger issue. My advice is to look at your Dagger setup carefully.
For me, I had recently removed dagger from a project and forgot to remove the #Singleton and #Inject annotations from relevant classes.
For me, its painfully removing all the #Singleton and #OpenForTesting on my Module classes. And removing two DAO classes and Repository whose backing model classes is no longer annotated with #Entity.
For me was in here:
apply plugin: 'kotlin-android-extensions'
In my case I was using this ""com.fasterxml.jackson.core:jackson-databind:2.7.3" library, but later I removed this dependency from gradle, but didn't remove the code that I was using of this library, so removed code and annotations related to this library solved my problem.
Just had a similar problem: I was trying to use picocli's #Command annotation and was getting the same error. It turned out to be an issue with my imports. I was importing this and other annotations via a wildcard import: import picocli.CommandLine.*. When i replaced it with separate imports for each annotation (among which was import picocli.CommandLine.Command), kapt began working correctly.
I assume kapt simply doesn't understand wildcard imports.
For me the problem was caused by migration to view binding from kotlin-android-extensions and Android Studio couldn't find #Parcelize annotation. To add annotations back add this to build.gradle:
apply plugin: 'kotlin-parcelize'
I was experimenting with my project's build.gradle. Currently my project consist of several modules, each of these module have common dependencies, such as android support or network library. I'm Experimenting with gradle dependencies.
I've declared a group of dependencies named lib_mandatory() in file lib-group.gradle, but when I tried to include it in my app's build.gradle the gradle sync failed.
Error:Could not find method lib_mandatory() for arguments [] on object of type org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.
How can I fix this? or any hints about what this error means?
Update:
Here's the lib-group.gradle
def dependencyGroup(Closure closure) {
closure.delegate = dependencies
return closure
}
def lib_mandatory = dependencyGroup{
implementation libraries.rxjava
implementation libraries.rxandroid
}
and here's the app's build.gradle
apply from: '../lib-group.gradle'
dependencies {
lib_mandatory()
}
The approach that is used in that article is a bit different, the article used the function inside the lib-group.gradle and only applied (apply from ...) the lib-group.gradle in the app's build.gradle.
In your approach, you're trying to use the function in the app's build.gradle.
If you want your functions to be accessed from other files, you should use ext instead of def. You might want to read this:
Gradle def vs ext
I am converting my Android application from Java to Kotlin. It is working fine, except when I try to convert a file that is using Android Data Binding Library.
In that case, Android Studio complains at compile time about unresolved reference:
Error:(10, 44) Unresolved reference: AdapterHistoriesListBinding
Where AdapterHistoriesListBinding is the name of a file that should be generated by the Data Binding Library. It was working correctly in Java, so I guess it is an issue with Kotlin.
I am using Android Studio 2.0.0-beta6, Android Gradle Plugin 2.0.0-beta6 and Kotlin 1.0.
Is there something to do to make the Data Binding Library work with Kotlin?
Few steps to setup databinding in your Kotlin project.
Tell kapt to use databinding compiler in module dependencies:
dependencies {
kapt 'com.android.databinding:compiler:2.0.0-beta6'
}
As Shintaro Katafuchi mentioned, you should tell kapt to generate stubs.
kapt {
generateStubs = true
}
Have you tried adding following setting in your build.gradle?
kapt {
generateStubs = true
}