Hilt ‐ Scoping with with both @Singletion and @SingletonComponent annotations

Observation

• Here when both annotation is used you can observe that when the class is loaded and the Instance is injected the instance class is instantiated.
• And the address remains even after multiple clicks.
• When you rotate the device the Instance class is not re-instantiated and so the address still remains constant.

Output

// When activity is loaded for the first time 
HiltNetworkService class is built
// Click on the Button to call the injected reference in activity for the first time
Reference address:-> 72836706
// Click on the Button to call the injected reference in activity for the second time
Reference address:-> 72836706
// When you rotate the screen 
// Click on the Button to call the injected reference in activity for the third time
Reference address:-> 72836706

Implementations

SerializationService.kt

class SerializationService  @Inject constructor() {

    init { PrintUtils.printLog("HiltNetworkService class is built") }

    fun serializeData(data : String) {
        PrintUtils.printLog("Reference address:-> $data")
    }
}

Modules

HiltScopingApplicationModule.kt

@InstallIn(SingletonComponent::class)
@Module
object HiltScopingApplicationModule {

    @Singleton
    @Provides
    fun getSerializationService() : SerializationService {
        return SerializationService()
    }

}

Activity

MyActivity.kt

@AndroidEntryPoint
class MyActivity : AppCompatActivity() {

    private lateinit var binding: ActivityHiltScopingBinding

    @Inject lateinit var serializationService : SerializationService

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityHiltScopingBinding.inflate(layoutInflater)
        setContentView(binding.root)
        setOnClickListeners();
    }

    private fun setOnClickListeners() {
        binding.apply {
            singletonCompWithSingletonAnnotationId.setOnClickListener {
                val code = serializationService.hashCode().toString()
                serializationService.serializeData(code)
            }
        }
    }
}