Hi, how can I access a generic type T for a class ...

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[juliocbcotta]

Hi, how can I access a generic type T for a class ?

abstract class TestCase<T : Activity>() {
    val classz = (javaClass
            .genericSuperclass as ParameterizedType).getActualTypeArguments()[0] as Class<T>
    @Rule
    @JvmField
    val rule = IntentsTestRule(classz, false, false)
	}

This seems to work to open FooTestCase: TestCase<ActivityA>, but not to BarTestCase: FooTestCase...

[Andreas Sinz]

what exactly doesn't work?

[diesieben07]

You need to walk up the superclass tree until you find the TestCase class and then grab the genericSuperclass for that.

[juliocbcotta]

java.lang.ClassCastException: java.lang.Class cannot be cast to java.lang.reflect.ParameterizedType

[diesieben07]

Because the superclass of BarTestCase is FooTestCase, which is not parameterized

[juliocbcotta]

Is there a generic way to get that T value?

[diesieben07]

You have to loop until you find the class you need.

[diesieben07]

You could use Guava's TypeToken for an existing implementation.

[juliocbcotta]

ok, I thought maybe Kotlin could have something to make it easier. Thanks