Hilt ‐ Interface Injection

Contents
Observations
Output
Code

Observation

• If you observe the Religion class type has the object of Buddhism Religion instantiated by the hilt.
• Now when you inject the Religion into the activity, You get the Buddhism reference.

Output

Religion instance -> 226246109
BuddhismReligion -> Printed

Code

Contents
Implementation
Modules
Activity

Implementation

Religion.kt

interface Religion {
    fun getReligionName() : String
}

JainismReligion.kt

class JainismReligion @Inject constructor() : Religion {
    override fun getReligionName(): String {
        return "JainismReligion -> Printed"
    }
}

Hinduism.kt

class Hinduism {
    init {
        PrintUtils.printLog("Hinduism constructor is invoked !")
    }
}

BuddhismReligion.kt

class BuddhismReligion @Inject constructor() : Religion {
    override fun getReligionName(): String {
        return "BuddhismReligion -> Printed"
    }
}

Modules

ReligionModule.kt

@InstallIn(ActivityComponent::class)
@Module
object ReligionModule {
    @Provides
    fun providesHinduism() : Hinduism { return Hinduism() }
    @Provides
    fun providesReligion() : Religion { return BuddhismReligion() }
}

Activity

MyActivity.kt

@AndroidEntryPoint
class MyActivity : AppCompatActivity() {

    private lateinit var binding: ActivityHiltInterfaceInjectionBinding

    @Inject lateinit var religion : Religion

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

    private fun setOnClickListeners() {
        binding.apply {
            initiateId.setOnClickListener {
                PrintUtils.printLog("Religion instance -> "+religion.hashCode().toString())
                PrintUtils.printLog(religion.getReligionName())
            }
        }
    }
}