Develop Reference

Android Espresso Testing: java.lang.NullPointerException: Can't toast on a thread that has not called Looper.prepare()

I am almost new to android testing and following the official docs and Udacity course for learning purposes.
Coming to the issue I want to check when the task is completed or incompleted to be displayed properly or not, for this I wrote a few tests. Here I got the exception that toast can not be displayed on a thread that has not called Looper.prepare.
When I comment out the toast msg live data updating line of code then all tests work fine and pass successfully. I am new to android testing and searched out a lot but did not get any info to solve this issue. Any help would be much appreciated. A little bit of explanation will be much more helpful if provided.
Below is my test class source code along with ViewModel, FakeRepository, and fragment source code.
Test Class.
#ExperimentalCoroutinesApi
#MediumTest
#RunWith(AndroidJUnit4::class)
class TaskDetailFragmentTest {
#get:Rule
var mainCoroutineRule = MainCoroutineRule()
#get:Rule
val rule = InstantTaskExecutorRule()
private lateinit var tasksRepository: FakeTasksRepository
#Before
fun setUp() {
tasksRepository = FakeTasksRepository()
ServiceLocator.taskRepositories = tasksRepository
}
#Test
fun addNewTask_addNewTaskToDatabase() = mainCoroutineRule.runBlockingTest {
val newTask = Task(id = "1", userId = 0, title = "Hello AndroidX World",false)
tasksRepository.addTasks(newTask)
val task = tasksRepository.getTask(newTask.id)
assertEquals(newTask.id,(task as Result.Success).data.id)
}
#Test
fun activeTaskDetails_DisplayedInUi() = mainCoroutineRule.runBlockingTest {
val newTask = Task(id = "2", userId = 0, title = "Hello AndroidX World",false)
tasksRepository.addTasks(newTask)
val bundle = TaskDetailFragmentArgs(newTask.id).toBundle()
launchFragmentInContainer<TaskDetailFragment>(bundle, R.style.Theme_ToDoWithTDD)
onView(withId(R.id.title_text)).check(matches(isDisplayed()))
onView(withId(R.id.title_text)).check(matches(withText("Hello AndroidX World")))
onView(withId(R.id.complete_checkbox)).check(matches(isDisplayed()))
onView(withId(R.id.complete_checkbox)).check(matches(isNotChecked()))
}
#Test
fun completedTaskDetails_DisplayedInUI() = mainCoroutineRule.runBlockingTest {
val newTask = Task(id = "2", userId = 0, title = "Hello AndroidX World",true)
tasksRepository.addTasks(newTask)
val bundle = TaskDetailFragmentArgs(newTask.id).toBundle()
launchFragmentInContainer <TaskDetailFragment>(bundle,R.style.Theme_ToDoWithTDD)
onView(withId(R.id.title_text)).check(matches(isDisplayed()))
onView(withId(R.id.title_text)).check(matches(withText("Hello AndroidX World")))
onView(withId(R.id.complete_checkbox)).check(matches(isDisplayed()))
onView(withId(R.id.complete_checkbox)).check(matches(isChecked()))
}
#After
fun tearDown() = mainCoroutineRule.runBlockingTest {
ServiceLocator.resetRepository()
}
}
FakeRepository class.
class FakeTasksRepository: TasksRepository {
var tasksServiceData: LinkedHashMap<String,Task> = LinkedHashMap()
private val observableTasks: MutableLiveData<Result<List<Task>>> = MutableLiveData()
private var shouldReturnError: Boolean = false
fun setReturnError(value: Boolean) {
shouldReturnError = value
}
override fun observeTasks(): LiveData<Result<List<Task>>> {
return observableTasks
}
override fun observeTask(taskId: String): LiveData<Result<Task>> {
runBlocking { fetchAllToDoTasks() }
return observableTasks.map { tasks ->
when(tasks) {
is Result.Loading -> Result.Loading
is Result.Error -> Result.Error(tasks.exception)
is Result.Success -> {
val task = tasks.data.firstOrNull() { it.id == taskId }
?: return#map Result.Error(Exception("Not found"))
Result.Success(task)
}
}
}
}
override suspend fun completeTask(id: String) {
tasksServiceData[id]?.completed = true
}
override suspend fun completeTask(task: Task) {
val compTask = task.copy(completed = true)
tasksServiceData[task.id] = compTask
fetchAllToDoTasks()
}
override suspend fun activateTask(id: String) {
tasksServiceData[id]?.completed = false
}
override suspend fun activateTask(task: Task) {
val activeTask = task.copy(completed = false)
tasksServiceData[task.id] = activeTask
fetchAllToDoTasks()
}
override suspend fun getTask(taskId: String): Result<Task> {
if (shouldReturnError) return Result.Error(Exception("Test Exception"))
tasksServiceData[taskId]?.let {
return Result.Success(it)
}
return Result.Error(Exception("Could not find task"))
}
override suspend fun getTasks(): Result<List<Task>> {
return Result.Success(tasksServiceData.values.toList())
}
override suspend fun saveTask(task: Task) {
tasksServiceData[task.id] = task
}
override suspend fun clearAllCompletedTasks() {
tasksServiceData = tasksServiceData.filterValues {
!it.completed
} as LinkedHashMap<String, Task>
}
override suspend fun deleteAllTasks() {
tasksServiceData.clear()
fetchAllToDoTasks()
}
override suspend fun deleteTask(taskId: String) {
tasksServiceData.remove(taskId)
fetchAllToDoTasks()
}
override suspend fun fetchAllToDoTasks(): Result<List<Task>> {
if(shouldReturnError) {
return Result.Error(Exception("Could not find task"))
}
val tasks = Result.Success(tasksServiceData.values.toList())
observableTasks.value = tasks
return tasks
}
override suspend fun updateLocalDataStore(list: List<Task>) {
TODO("Not yet implemented")
}
fun addTasks(vararg tasks: Task) {
tasks.forEach {
tasksServiceData[it.id] = it
}
runBlocking {
fetchAllToDoTasks()
}
}
}
Fragment class.
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
viewModel.loadTaskById(args.taskId)
setUpToast(this,viewModel.toastText)
viewModel.editTaskEvent.observe(viewLifecycleOwner, {
it?.let {
val action = TaskDetailFragmentDirections
.actionTaskDetailFragmentToAddEditFragment(
args.taskId,
resources.getString(R.string.edit_task)
)
findNavController().navigate(action)
}
})
binding.editTaskFab.setOnClickListener {
viewModel.editTask()
}
}
ViewModel class.
class TaskDetailViewModel(
private val tasksRepository: TasksRepository
) : ViewModel() {
private val TAG = "TaskDetailViewModel"
private val _taskId: MutableLiveData<String> = MutableLiveData()
private val _task = _taskId.switchMap {
tasksRepository.observeTask(it).map { res ->
Log.d("Test","res with value ${res.toString()}")
isolateTask(res)
}
}
val task: LiveData<Task?> = _task
private val _toastText = MutableLiveData<Int?>()
val toastText: LiveData<Int?> = _toastText
private val _dataLoading = MutableLiveData<Boolean>()
val dataLoading: LiveData<Boolean> = _dataLoading
private val _editTaskEvent = MutableLiveData<Unit?>(null)
val editTaskEvent: LiveData<Unit?> = _editTaskEvent
fun loadTaskById(taskId: String) {
if(dataLoading.value == true || _taskId.value == taskId) return
_taskId.value = taskId
Log.d("Test","loading task with id $taskId")
}
fun editTask(){
_editTaskEvent.value = Unit
}
fun setCompleted(completed: Boolean) = viewModelScope.launch {
val task = _task.value ?: return#launch
if(completed) {
tasksRepository.completeTask(task.id)
_toastText.value = R.string.task_marked_complete
}
else {
tasksRepository.activateTask(task.id)
_toastText.value = R.string.task_marked_active
}
}
private fun isolateTask(result: Result<Task?>): Task? {
return if(result is Result.Success) {
result.data
} else {
_toastText.value = R.string.loading_tasks_error
null
}
}
#Suppress("UNCHECKED_CAST")
class TasksDetailViewModelFactory(
private val tasksRepository: TasksRepository
): ViewModelProvider.NewInstanceFactory() {
override fun <T : ViewModel> create(modelClass: Class<T>): T {
return (TaskDetailViewModel(
tasksRepository
) as T)
}
}
}
In this method in ViewModel when I comment out the below line of code all tests passed.
_toastText.value = R.string.loading_tasks_error
private fun isolateTask(result: Result<Task?>): Task? {
return if(result is Result.Success) {
result.data
} else {
_toastText.value = R.string.loading_tasks_error // Comment out this line then all test passed.
null
}
}

Kotlin EventBus triggered twice

I use this code for eventBus in kotlin, but it triggers twice. I don't know why this happens
object EventBus {
val bus: BroadcastChannel<Any> = BroadcastChannel<Any>(1)
private val parentJob = Job()
private val coroutineContext: CoroutineContext
get() = parentJob + Dispatchers.Default
private val scope = CoroutineScope(coroutineContext)
fun send(o: Any) {
scope.launch {
bus.send(o)
}
}
inline fun <reified T> asChannel(): ReceiveChannel<T> {
return bus.openSubscription().filter { it is T }.map { it as T }
}
}
and use it in this way
EventBus.send(NetEvent(false))
and listen t it as below (this code runs twice)
var subscription = EventBus.asChannel<NetEvent>()
var s = scope.launch {
subscription.consumeEach { event ->
Timber.i("NetEvent ${event.isConected}")
currentNet = event.isConected
}
}

I would prefer MutableSharedFlow:
class EventBus {
private val events = MutableSharedFlow<Any>()
suspend fun dispatch(event: Any) {
events.emit(event)
}
suspend fun on(coroutineScope: CoroutineScope, handler: suspend (Any) -> Unit) =
coroutineScope.launch(start = CoroutineStart.UNDISPATCHED) {
events.asSharedFlow().collect { event -> handler(event) }
}
}
class EventBusTest {
#Test
fun testEventBus() {
val events = ConcurrentLinkedDeque<String>()
runBlocking {
val eventBus = EventBus()
val job1 = eventBus.on(this) { events.add("1: $it") }
eventBus.dispatch("a")
val job2 = eventBus.on(this) { events.add("2: $it") }
eventBus.dispatch("b")
job1.cancelAndJoin()
eventBus.dispatch("c")
job2.cancelAndJoin()
}
assertEquals(listOf("1: a", "1: b", "2: b", "2: c"), events.toList())
}
}

How can I convert LiveData to 2 pieces of liveData?

I have configLiveData:LiveData<Response<ConfigFile>> where Response is
sealed class Response<out T> {
data class Success<out T>(val data: T) : Response<T>()
data class Failure<out T>(val message: String) : Response<T>()
}
now in ViewModel I want to transform configLiveData to two different
LiveDatas 1.LiveData<ConfigFile> and 2. LiveData<String> and as a result of transformation one of them will be empty.
but I want to get ride of LiveData<Response<ConfigFile>> and have instead of it LiveData<ConfigFile>
override suspend fun fetchConfigFile(): Response<ConfigFile> {
return suspendCoroutine { cont ->
EnigmaRiverContext.getHttpHandler().doHttp(AppConstants.getPath().append("config/appConfig.json").toURL(),
JsonHttpCall("GET"), object : JsonReaderResponseHandler() {
override fun onSuccess(jsonReader: JsonReader) {
try {
val successObject = ApiConfigFile(jsonReader)
cont.resume(Response.Success(successObject.toPresenterModel()))
} catch (e: IOException) {
cont.resume(Response.Failure(e.message))
} catch (e: Exception) {
cont.resume(Response.Failure(e.message ))
}
}
override fun onError(error: Error?) {
cont.resume(Response.Failure("error.message"))
}
})
}
}
It is how my Repository looks like
private fun fetchConfig() {
uiScope.launch {
when (val result = homeRepository.fetchConfigFile()) {
is Response.Success<ConfigFile> -> {
postValue(Response.Success(result.data))
}
is Response.Failure -> postValue(Response.Failure(result.message))
}
}
}
class ConfigFileLiveData #Inject constructor(val homeRepository: IHomeRepository) : LiveData<Response<ConfigFile>>() {
private val liveDataJob = Job()
private val uiScope = CoroutineScope(Dispatchers.Main + liveDataJob)
override fun onActive() {
fetchConfig()
}
private fun fetchConfig() {
viewModelScope.launch {
when (val result = homeRepository.fetchConfigFile()) {
is Response.Success<ConfigFile> -> {
postValue(Response.Success(result.data))
}
is Response.Failure -> postValue(Response.Failure(result.message))
}
}
}
}
I have `ConfigFileLiveData` which is singleton and I want to use this liveData in other viewModels as I need to fetch config once and use it in different ViewModels
class ConfigFileLiveData #Inject constructor(val homeRepository: IHomeRepository) : LiveData<Response<ConfigFile>>() {
override fun onActive() {
fetchConfig()
}
private fun fetchConfig() {
viewModelScope.launch {
when (val result = homeRepository.fetchConfigFile()) {
is Response.Success<ConfigFile> -> {
postValue(Response.Success(result.data))
}
is Response.Failure -> postValue(Response.Failure(result.message))
}
}
}
}

In Viewmodel Define two LiveData variable.
private var configLiveData = MutableLiveData<ConfigFile>()
private var stringLiveData = MutableLiveData<String>()
Modify this method
private fun fetchConfig() {
uiScope.launch {
when (val result = homeRepository.fetchConfigFile()) {
is Response.Success<ConfigFile> -> {
configLiveData.value = Response.Success(result.data)
}
is Response.Failure -> {
stringLiveData.value = Response.Failure(result.message)
}
}
}
}

Android ViewState using RxJava or kotlin coroutines

I'm trying to learn how to use RxJava in Android, but have run into a dead end. I have the following DataSource:
object DataSource {
enum class FetchStyle {
FETCH_SUCCESS,
FETCH_EMPTY,
FETCH_ERROR
}
var relay: BehaviorRelay<FetchStyle> = BehaviorRelay.createDefault(FetchStyle.FETCH_ERROR)
fun fetchData(): Observable<DataModel> {
return relay
.map { f -> loadData(f) }
}
private fun loadData(f: FetchStyle): DataModel {
Thread.sleep(5000)
return when (f) {
FetchStyle.FETCH_SUCCESS -> DataModel("Data Loaded")
FetchStyle.FETCH_EMPTY -> DataModel(null)
FetchStyle.FETCH_ERROR -> throw IllegalStateException("Error Fetching")
}
}
}
I want to trigger an update downstream, whenever I change the value of relay, but this doesn't happen. It works when the Activity is initialized, but not when I'm updating the value. Here's my ViewModel, from where I update the value:
class MainViewModel : ViewModel() {
val fetcher: Observable<UiStateModel> = DataSource.fetchData().replay(1).autoConnect()
.map { result -> UiStateModel.from(result) }
.onErrorReturn { exception -> UiStateModel.Error(exception) }
.startWith(UiStateModel.Loading())
.subscribeOn(Schedulers.io())
.observeOn(Schedulers.io())
fun loadSuccess() {
DataSource.relay.accept(DataSource.FetchStyle.FETCH_SUCCESS)
}
fun loadEmpty() {
DataSource.relay.accept(DataSource.FetchStyle.FETCH_EMPTY)
}
fun loadError() {
DataSource.relay.accept(DataSource.FetchStyle.FETCH_ERROR)
}
}
This is the code from the Activity that does the subsciption:
model.fetcher
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe({
uiState -> mainPresenter.loadView(uiState)
})

Ended up using kotlin coroutines instead, as I was unable to re-subscribe to ConnectableObservable and start a new fetch.
Here's the code for anyone interested.
The presenter:
class MainPresenter(val view: MainView) {
private lateinit var subscription: SubscriptionReceiveChannel<UiStateModel>
fun loadSuccess(model: MainViewModel) {
model.loadStyle(DataSource.FetchStyle.FETCH_SUCCESS)
}
fun loadError(model: MainViewModel) {
model.loadStyle(DataSource.FetchStyle.FETCH_ERROR)
}
fun loadEmpty(model: MainViewModel) {
model.loadStyle(DataSource.FetchStyle.FETCH_EMPTY)
}
suspend fun subscribe(model: MainViewModel) {
subscription = model.connect()
subscription.subscribe { loadView(it) }
}
private fun loadView(uiState: UiStateModel) {
when(uiState) {
is Loading -> view.isLoading()
is Error -> view.isError(uiState.exception.localizedMessage)
is Success -> when {
uiState.result != null -> view.isSuccess(uiState.result)
else -> view.isEmpty()
}
}
}
fun unSubscribe() {
subscription.close()
}
}
inline suspend fun <E> SubscriptionReceiveChannel<E>.subscribe(action: (E) -> Unit) = consumeEach { action(it) }
The view:
...
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
launch(UI) {
mainPresenter.subscribe(model)
}
btn_load_success.setOnClickListener {
mainPresenter.loadSuccess(model)
}
btn_load_error.setOnClickListener {
mainPresenter.loadError(model)
}
btn_load_empty.setOnClickListener {
mainPresenter.loadEmpty(model)
}
}
override fun onDestroy() {
super.onDestroy()
Log.d("View", "onDestroy()")
mainPresenter.unSubscribe()
}
...
The model:
class MainViewModel : ViewModel() {
val TAG = this.javaClass.simpleName
private val stateChangeChannel = ConflatedBroadcastChannel<UiStateModel>()
init {
/** When the model is initialized we immediately start fetching data */
fetchData()
}
override fun onCleared() {
super.onCleared()
Log.d(TAG, "onCleared() called")
stateChangeChannel.close()
}
fun connect(): SubscriptionReceiveChannel<UiStateModel> {
return stateChangeChannel.openSubscription()
}
fun fetchData() = async {
stateChangeChannel.send(UiStateModel.Loading())
try {
val state = DataSource.loadData().await()
stateChangeChannel.send(UiStateModel.from(state))
} catch (e: Exception) {
Log.e("MainModel", "Exception happened when sending new state to channel: ${e.cause}")
}
}
internal fun loadStyle(style: DataSource.FetchStyle) {
DataSource.style = style
fetchData()
}
}
And here's a link to the project on github.

Android NsdManager not able to discover services

I'm running into a problem with Androids NsdManager when following their tutorial Using Network Service Discovery.
I have a few zeroconf/bonjour hardware devices on my network. From my mac I can discover all of them as expected from my terminal with the following
dns-sd -Z _my-mesh._tcp.
From my Android app's first run I can flawlessly discover these services using NsdManager. However if I restart the application and try again none of the services are found. onDiscoveryStarted gets called successfully but then nothing else after. While waiting I can confirm from my mac that the services are still successfully there.
I can then turn on my Zeroconf app (on Android) and it will show the services like my mac. When I return to my app I see it immediately receive all the callbacks I expected previously. So I believe something is wrong with my approach, however I'm not sure what. Below is the code I use to discover and resolve services. The view is a giant textview (in a scroll view) I keep writing text to for debugging easier.
import android.annotation.SuppressLint
import android.content.Context
import android.net.nsd.NsdManager
import android.net.nsd.NsdServiceInfo
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.TextView
class MainActivity : AppCompatActivity(),
NsdManager.DiscoveryListener {
private var nsdManager: NsdManager? = null
private var text: TextView? = null
private var isResolving = false
private val services = ArrayList<ServiceWrapper>()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
this.text = findViewById(R.id.text)
this.nsdManager = application.getSystemService(Context.NSD_SERVICE) as NsdManager
}
override fun onResume() {
super.onResume()
this.nsdManager?.discoverServices("_my-mesh._tcp.", NsdManager.PROTOCOL_DNS_SD, this)
write("Resume Discovering Services")
}
override fun onPause() {
super.onPause()
this.nsdManager?.stopServiceDiscovery(this)
write("Pause Discovering Services")
}
override fun onServiceFound(serviceInfo: NsdServiceInfo?) {
write("onServiceFound(serviceInfo = $serviceInfo))")
if (serviceInfo == null) {
return
}
add(serviceInfo)
}
override fun onStopDiscoveryFailed(serviceType: String?, errorCode: Int) {
write("onStopDiscoveryFailed(serviceType = $serviceType, errorCode = $errorCode)")
}
override fun onStartDiscoveryFailed(serviceType: String?, errorCode: Int) {
write("onStartDiscoveryFailed(serviceType = $serviceType, errorCode = $errorCode)")
}
override fun onDiscoveryStarted(serviceType: String?) {
write("onDiscoveryStarted(serviceType = $serviceType)")
}
override fun onDiscoveryStopped(serviceType: String?) {
write("onDiscoveryStopped(serviceType = $serviceType)")
}
override fun onServiceLost(serviceInfo: NsdServiceInfo?) {
write("onServiceLost(serviceInfo = $serviceInfo)")
}
private fun createResolveListener(): NsdManager.ResolveListener {
return object : NsdManager.ResolveListener {
override fun onResolveFailed(serviceInfo: NsdServiceInfo?, errorCode: Int) {
write("onResolveFailed(serviceInfo = $serviceInfo, errorCode = $errorCode)")
isResolving = false
resolveNext()
}
override fun onServiceResolved(serviceInfo: NsdServiceInfo?) {
write("onServiceResolved(serviceInfo = $serviceInfo)")
if (serviceInfo == null) {
return
}
for (servicewrapper in services) {
if (servicewrapper.serviceInfo.serviceName == serviceInfo.serviceName) {
servicewrapper.resolve(serviceInfo)
}
}
isResolving = false
resolveNext()
}
}
}
#SuppressLint("SetTextI18n")
private fun write(text: String?) {
this.text?.let {
it.post({
it.text = it.text.toString() + "\n" + text + "\n"
})
}
}
fun add(serviceInfo: NsdServiceInfo) {
for (servicewrapper in services) {
if (servicewrapper.serviceInfo.serviceName == serviceInfo.serviceName) {
return
}
}
services.add(ServiceWrapper(serviceInfo))
resolveNext()
}
#Synchronized
fun resolveNext() {
if (isResolving) {
return
}
isResolving = true
for (servicewrapper in services) {
if (servicewrapper.isResolved) {
continue
}
write("resolving")
this.nsdManager?.resolveService(servicewrapper.serviceInfo, createResolveListener())
return
}
isResolving = false
}
inner class ServiceWrapper(var serviceInfo: NsdServiceInfo) {
var isResolved = false
fun resolve(serviceInfo: NsdServiceInfo) {
isResolved = true
this.serviceInfo = serviceInfo
}
}
}

Better late than never. Did not realize other people were having this issue too until now.
What we discovered was some routers were blocking or not correctly forwarding the packets back and forth. Our solution to this was using wire shark to detect what other popular apps were doing to get around the issue. Androids NsdManager has limited customizability so it required manually transmitting the packet over a MulticastSocket.
interface NsdDiscovery {
suspend fun startDiscovery()
suspend fun stopDiscovery()
fun setListener(listener: Listener?)
fun isDiscovering(): Boolean
interface Listener {
fun onServiceFound(ip:String, local:String)
fun onServiceLost(event: ServiceEvent)
}
}
#Singleton
class ManualNsdDiscovery #Inject constructor()
: NsdDiscovery {
//region Fields
private val isDiscovering = AtomicBoolean(false)
private var socketManager: SocketManager? = null
private var listener: WeakReference<NsdDiscovery.Listener> = WeakReference<NsdDiscovery.Listener>(null)
//endregion
//region NsdDiscovery
override suspend fun startDiscovery() = withContext(Dispatchers.IO) {
if (isDiscovering()) return#withContext
this#ManualNsdDiscovery.isDiscovering.set(true)
val socketManager = SocketManager()
socketManager.start()
this#ManualNsdDiscovery.socketManager = socketManager
}
override suspend fun stopDiscovery() = withContext(Dispatchers.IO) {
if (!isDiscovering()) return#withContext
this#ManualNsdDiscovery.socketManager?.stop()
this#ManualNsdDiscovery.socketManager = null
this#ManualNsdDiscovery.isDiscovering.set(false)
}
override fun setListener(listener: NsdDiscovery.Listener?) {
this.listener = WeakReference<NsdDiscovery.Listener>(listener)
}
#Synchronized
override fun isDiscovering(): Boolean {
return this.isDiscovering.get()
}
//endregion
private inner class SocketManager {
//region Fields
private val group = InetAddress.getByName("224.0.0.251")
?: throw IllegalStateException("Can't setup group")
private val incomingNsd = IncomingNsd()
private val outgoingNsd = OutgoingNsd()
//endregion
//region Constructors
//endregion
//region Methods
suspend fun start() {
this.incomingNsd.startListening()
this.outgoingNsd.send()
}
fun stop() {
this.incomingNsd.stopListening()
}
//endregion
private inner class OutgoingNsd {
//region Fields
private val socketMutex = Mutex()
private var socket = MulticastSocket(5353)
suspend fun setUpSocket() {
this.socketMutex.withLock {
try {
this.socket = MulticastSocket(5353)
this.socket.reuseAddress = true
this.socket.joinGroup(group)
} catch (e: SocketException) {
return
}
}
}
suspend fun tearDownSocket() {
this.socketMutex.withLock {
this#OutgoingNsd.socket.close()
}
}
//ugly code but here is the packet
private val bytes = byteArrayOf(171.toByte(), 205.toByte(), 1.toByte(), 32.toByte(),
0.toByte(), 1.toByte(), 0.toByte(), 0.toByte(),
0.toByte(), 0.toByte(), 0.toByte(), 0.toByte(),
9.toByte(), 95.toByte(), 101.toByte(), 118.toByte(),
97.toByte(), 45.toByte(), 109.toByte(), 101.toByte(),
115.toByte(), 104.toByte(), 4.toByte(), 95.toByte(),
116.toByte(), 99.toByte(), 112.toByte(), 5.toByte(),
108.toByte(), 111.toByte(), 99.toByte(), 97.toByte(),
108.toByte(), 0.toByte(), 0.toByte(), 12.toByte(),
0.toByte(), 1.toByte())
private val outPacket = DatagramPacket(bytes,
bytes.size,
this#SocketManager.group,
5353)
//endregion
//region Methods
#Synchronized
suspend fun send() {
withContext(Dispatchers.Default) {
setUpSocket()
try {
this#OutgoingNsd.socket.send(this#OutgoingNsd.outPacket)
delay(1500L)
tearDownSocket()
} catch (e: Exception) {
}
}
}
//endregion
}
private inner class IncomingNsd {
//region Fields
private val isRunning = AtomicBoolean(false)
private var socket = MulticastSocket(5353)
//endregion
//region Any
fun setUpSocket() {
try {
this.socket = MulticastSocket(5353)
this.socket.reuseAddress = true
this.socket.joinGroup(group)
} catch (e: SocketException) {
} catch (e: BindException) {
}
}
fun run() {
GlobalScope.launch(Dispatchers.Default) {
setUpSocket()
try {
while (this#IncomingNsd.isRunning.get()) {
val bytes = ByteArray(4096)
val inPacket = DatagramPacket(bytes, bytes.size)
this#IncomingNsd.socket.receive(inPacket)
val incoming = DNSIncoming(inPacket)
for (answer in incoming.allAnswers) {
if (answer.key.contains("_my_mesh._tcp")) {
this#ManualNsdDiscovery.listener.get()?.onServiceFound(answer.recordSource.hostAddress, answer.name)
return#launch
}
}
}
this#IncomingNsd.socket.close()
} catch (e: Exception) {
}
}
}
//endregion
//region Methods
#Synchronized
fun startListening() {
if (this.isRunning.get()) {
return
}
this.isRunning.set(true)
run()
}
#Synchronized
fun stopListening() {
if (!this.isRunning.get()) {
return
}
this.isRunning.set(false)
}
//endregion
}
}
}