Call a java class from a kotlin activity

Question

I am working on a project on Android Studio. I have the main activity inside a kotlin file (MainActivity.kt) and from it I am trying to call a static method(start_netClient()) from inside a java file (dists.java) via an Intent object by putting this listener for my bbutton inside the onCreate() of the MainActivity :

        bbutton.setOnClickListener(object: View.OnClickListener {
        override fun onClick(view: View): Unit {
            // Handler code here.
            val intent = Intent(this, Net_Activity::class.java)
            startActivity(intent)
        }
    })

The Net_Activity and its content:

class Net_Activity: AppCompatActivity() {

fun main(args: Array<String>) {
    dists.start_netClient()
}
}

What I get for this code during the build is this error on Intent on the MainActivity.kt:

Error:(65, 30) None of the following functions can be called with the arguments supplied:
public constructor Intent(p0: Context!, p1: Class<*>!) defined in android.content.Intent
public constructor Intent(p0: String!, p1: Uri!) defined in android.content.Intent

I am relatively new to the whole Android thing, but what is it that I am missing, and how is it possible to connect a java method and a kotlin class via the Intent? Is it best effort to use two Activities or is there a different approach?

Answer 1

It seems that when you use this, you're referencing the listener object (View.OnClickListener) rather than your activity. You should be able to fix this by using this@Net_Activity, which references your activity instead of the listener. The full line should look like so:

val intent = Intent(this@Net_Activity, Net_Activity::class.java)

When you declare an object in Kotlin (via the object keyword) you're defining an anonymous class, and then creating a single instance of this class. This allows you to override methods for things like listeners, but as you've discovered, it means you have to double check your uses of this.