cannot find class symbol error in android studio - kotlin

Question

i am trying to reference a kotlin class in a fragment class in java and it results to error saying that it cannot find the symbol of the kotlin class.
fragment class
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootview = inflater.inflate(R.layout.fragment_flashcards, container, false);
go = (ImageButton) rootview.findViewById(R.id.goBtn);
//Instructions audio
instruct = (ImageButton) rootview.findViewById(R.id.soundBtn);
MediaPlayer.create(getActivity(), R.raw.instructions);
//Click go button to explore flashcards
go.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(getActivity(), Flashcards1.class));
}
});
return rootview;
}
}
this is where the error is
startActivity(new Intent(getActivity(), Flashcards1.class));
build.gradle app
plugins {
id 'com.android.application'
id 'com.google.gms.google-services'
}
android {
compileSdk 33
defaultConfig {
applicationId "com.example.salitongue_updated"
minSdk 27
targetSdk 33
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
buildFeatures {
viewBinding true
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
}
dependencies {
implementation 'androidx.appcompat:appcompat:1.5.0'
implementation 'com.google.android.material:material:1.6.1'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
implementation 'com.google.firebase:firebase-database:20.0.5'
implementation 'com.google.firebase:firebase-firestore:24.2.2'
implementation 'com.google.firebase:firebase-auth:21.0.7'
implementation 'androidx.navigation:navigation-fragment:2.5.1'
implementation 'androidx.navigation:navigation-ui:2.5.1'
implementation "androidx.fragment:fragment-ktx:1.6.0-alpha02"
//testImplementation 'junit:junit:4.13.2'
testImplementation 'junit:junit:4.+'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}
build.gradle
buildscript {
dependencies {
classpath 'com.google.gms:google-services:4.3.13'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.10"
}
}// Top-level build file where you can add configuration options common to all sub-projects/modules.
plugins {
id 'com.android.application' version '7.2.2' apply false
id 'com.android.library' version '7.2.2' apply false
}
task clean(type: Delete) {
delete rootProject.buildDir
}

Answer 1

I think your problem is that you don't have Kotlin set up for your app module. You have the plugin dependency added to your main build.gradle, but you're not applying the plugin in the app module build.gradle. You also don't have the kotlin-stdlib dependency added to that module. Have a look at the example setup here (you have to scroll down a bit to the code snippets).
I don't know a lot about Gradle and the ways to configure your build files, so it's possible you've got it set up a different way and it's fine - but you should be able to see Kotlin class files from Java without doing anything special:
Kotlin code can be easily called from Java. For example, instances of a Kotlin class can be seamlessly created and operated in Java methods.
So it seems like maybe it's just not set up, and that's why it's not working for you. If Kotlin's working in the IDE (like popping up in code completion) but not when you try to build it, that sounds like the IDE plugin is set up fine, but not the stuff in your project. I don't know for sure, but hopefully it'll help!