activej-Inject, When the return value of a method has a generic

[zhangtianxiao]

activej-Inject, When the return value of a method has a generic

[eduard-vasinskyi]

Hi, @zhangtianxiao

There are three approaches to constructing a key of a generic type:

fun main() {
   val injector = Injector.of(MyBeansDescription())


   val type = Types.parameterizedType(Function::class.java, String::class.java, Integer::class.java)
   val instance1 = injector.getInstance(Key.ofType<Function<String, Int>>(type, "i1"))
   println(instance1.apply(""))


   val instance2 = injector.getInstance(object : Key<Function<String, Int>>("i1") {})
   println(instance2.apply(""))


   val instance3 = injector.getInstance(key<Function<String, Int>>("i1"))
   println(instance3.apply(""))
}


inline fun <reified T> key(qualifier: String) = object : Key<T>(qualifier) {}

First, you can construct a type manually via the Types API and then use the Key#ofType method to construct a Key.

Another approach is to pass a type in diamond brackets when creating an instance of an anonymous Key class.

The shortest option is to add a special key(String) function that would construct a key with a specified qualifier using diamond brackets to infer the type.