UsesReflectionToConstruct

The annotated code uses reflection to indirectly invoke a constructor of a class/interface, or its subclasses / interface implementers.

This annotation indicates to optimizers or shrinkers that the target constructor should be kept if the annotated code is reachable in the final application build.

@UsesReflectionToConstruct() is a convenience for @UsesReflectionToAccessMethod(methodName = "<init>")

import androidx.annotation.keep.UsesReflectionToConstruct

@UsesReflectionToConstruct(
    className = "com.example.PaymentProcessorImpl",
    parameterTypes = [], // default constructor, no parameters
)
fun constructMyType() {
    // impl class isn't always present, instantiate with reflection to attempt to discover
    Class.forName("com.example.PaymentProcessorImpl").getDeclaredConstructor().newInstance()
        as PaymentProcessor
}
 
import androidx.annotation.keep.UsesReflectionToConstruct

@UsesReflectionToConstruct(
    className = "com.example.PaymentProcessorImpl",
    parameterTypes = [TransactionAccess::class, Long::class],
)
fun constructMyType(transactionAccess: TransactionAccess, timeout: Long) {
    // impl class isn't always present, instantiate with reflection to attempt to discover
    Class.forName("com.example.PaymentProcessorImpl")
        .getDeclaredConstructor(TransactionAccess::class.java, Long::class.java)
        .newInstance() as PaymentProcessor
}
See also
UsesReflectionToAccessMethod
UsesReflectionToAccessField

Summary

Public constructors
UsesReflectionToConstruct(
    classConstant: KClass<*>,
    className: String,
    parameterTypes: Array<KClass<*>>,
    parameterTypeNames: Array<String>
)
Cmn

Public properties
KClass<*>

Class to be instantiated.
Cmn
String

Class to be instantiated.
Cmn
Array<String>

Defines which constructor to keep by specifying the parameter list types.
Cmn
Array<KClass<*>>

Defines which constructor to keep by specifying the parameter list types.
Cmn

Public constructors

UsesReflectionToConstruct

Cmn 
UsesReflectionToConstruct(
    classConstant: KClass<*> = Unspecified::class,
    className: String = "",
    parameterTypes: Array<KClass<*>> = [Unspecified::class],
    parameterTypeNames: Array<String> = [""]
)

Public properties

classConstant

Cmn 
val classConstant: KClass<*>

Class to be instantiated.

Mutually exclusive with className.

className

Cmn 
val className: String

Class to be instantiated.

Mutually exclusive with classConstant.

parameterTypeNames

Cmn 
val parameterTypeNames: Array<String>

Defines which constructor to keep by specifying the parameter list types.

If neither parameterTypes nor parameterTypeNames is specified then constructors with all parameter lists are kept.

Mutually exclusive with parameterTypes.

parameterTypes

Cmn 
val parameterTypes: Array<KClass<*>>

Defines which constructor to keep by specifying the parameter list types.

If neither parameterTypes nor parameterTypeNames is specified then constructors with all parameter lists are kept.

Mutually exclusive with parameterTypeNames.