JarCastingInfer hierarchy type parameters
Java/Kotlin utility to infer actual type for inherited type parameters
Infer generic types for inherited classes
If you have a class hierarchy where base class has type parameters, and you need to access actual type defined in inherited class you may pass it to constructor or defined an abstract method for that.
Without the library
abstract class Dao<E: Any> {
abstract val entityType: Class<E>
fun getTypeName() = entityType.name
}
class UserDao<User>: Dao<User>() {
override val entityType = User::class.java
}
class GroupDao<Group>: Dao<Group>() {
override val entityType = Group::class.java
}
With the library
But information about the type variable value for the class UserDao is actually available. You can get it using the method inferTypeParameter from the library.
abstract class Dao<E: Any> {
open val entityType: Class<E> = inferTypeParameterClass(Dao::class.java, "E", javaClass)
fun getTypeName() = entityType.name
}
class UserDao<User>: Dao<User>()
class GroupDao<Group>: Dao<Group>()
Check if a method overrides another method considering generics
open class Figure<A> {
open fun compare(that: A, p: String, i: Int) = false
}
class Rectangle<B> : Figure<B>() {
override fun compare(that: B, o: String, i: Int) = true
}
fun check() {
Rectangle<*>::compare.isOverriding(Figure<*>::compare) // true
}
Gradle and Maven
Gradle
repositories {
mavenCentral()
}
dependencies {
compile 'com.github.mazine:infer-hierarchy-type-parameter:$version'
}
Maven
<dependency>
<groupId>com.github.mazine</groupId>
<artifactId>infer-hierarchy-type-parameter</artifactId>
<version>$version</version>
</dependency>