如何从 Executor 的执行中返回值 - Kotlin

Question

How can I return value from execute of Executor :

fun MyFunc(): Int {
private val executor: Executor =
    Executors.newSingleThreadExecutor()
  executor.execute { appRepository.tblCoursesIsEmptyAppRepo() }
}

I used from postValue but it get me old value always.

Answer 1

Use kotlin Coroutines it's very rich and concise than Executor and you can get a value of livedata by postValue() method.

To use coroutine add gradle files:

def coroutines_version = "1.3.3"
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"

and use below code:

    val handler = CoroutineExceptionHandler { _, exception ->
        exception.printStackTrace()
    }

    CoroutineScope(Dispatchers.IO).launch(handler) {
        resultLiveData.postValue(appRepository.tblCoursesIsEmptyAppRepo())
    }

Answer 2

I used from bellow source code and it good work:

    val callable = Callable { appRepository.tblCoursesIsEmptyAppRepo() }

    val future = Executors.newSingleThreadExecutor().submit(callable)

    Log.i(TAG, future.get())