Kotlin Coroutine 基本的な使い方

,PUMJO$PSPVUJOF جຊతͳ࢖͍ํ

w Ϋϥεϝιουגࣜձࣾ w $9ࣄۀ෦ॴଐ w "1*։ൃɺ"84؀ڥߏஙɺӡ༻ w /&8 "OESPJE

ࠓ೔࿩͢͜ͱ w $PSPVUJOFͱ͸ w $PSPVUJOFͷ࢖͍Έͪ w جຊతͳ࢖͍ํ w ࣮ྫू

$PSPVUJOFͱ͸

$PSPVUJOFͱ͸ w ܰྔ5ISFBE w 5ISFBEͷΑ͏ʹѻ͑ͭ͋ͨΓʹඞཁͳϦ ιʔε͕5ISFBEΑΓ΋͍ܰ w ͨ͘͞ΜىಈͰ͖Δ

$PSPVUJOFͷ࢖͍ಓ 6 ϝΠϯ 6* εϨουͰߦ͏ͱ69ΛଛͶΔ  Մೳੑͷ͋Δॏ͍ͨॲཧΛผεϨουͰ࣮ߦ ͢Δ

ॏ͍ͨॲཧ 7 w *0ό΢ϯυͷॲཧ w ωοτϫʔΫΞΫηε w σΟεΫΞΫηε w $16ό΢ϯυͷॲཧ
w +40/ͷγϦΞϥΠζɺσγϦΞϥΠζ w Ϧετͷฒͼସ͑

جຊతͳ࢖͍ํ

جຊతͳ࢖͍ํ fun main(args: Array<String>) { println("Start") GlobalScope.launch { delay(1000) println("1")
} println("2") println("End") Thread.sleep(2000) } Start 2 End 1

$PSPVUJOFͱ͸ fun main(args: Array<String>) { println("Start") GlobalScope.launch { delay(1000) println("1")
} println("2") println("End") Thread.sleep(2000) } Start 2 End 1 $PSPVUJOFͰ࣮ߦ͞Ε ඇಉظʹॲཧ͞Ε͍ͯΔ

$PSPVUJOFͱ͸ fun main(args: Array<String>) { println("Start") GlobalScope.launch { delay(1000) println("1")
} println("2") println("End") Thread.sleep(2000) } Start 2 End 1 $PSPVUJOF #VJMEFS $PSPVUJOF 4DPQF

$PSPVUJOF4DPQF

4DPQF͸֊૚ߏ଄ʹͰ͖Δ 4DPQFʹෳ਺ͷ$PSPVUJOFΛ࣋ͯΔ

$PSPVUJOF4DPQF fun main(args: Array<String>) = runBlocking { println("Start") GlobalScope.launch {
delay(1000) println("1") } println("2") println("End") } Start 2 End

$PSPVUJOF4DPQF fun main(args: Array<String>) = runBlocking { println("Start") GlobalScope.launch {
delay(1000) println("1") } println("2") println("End") } Start 2 End (MPCBM4DPQF ʹͳΔͨΊSVO#MPDLJOHͷ είʔϓͰ͸ऴྃΛ·ͨͳ͍

$PSPVUJOF4DPQF fun main(args: Array<String>) = runBlocking { println("Start") launch {
delay(1000) println("1") } println("2") println("End") } Start 2 End 1

$PSPVUJOFͱ͸ fun main(args: Array<String>) = runBlocking { println("Start") launch {
delay(1000) println("1") } println("2") println("End") } Start 2 End 1 SVO#MPDLJOHͷείʔϓͷUIJT͸ $PSPVUJOF4DPQF SVO#MPDLJOHͷ4DPQFͷMBVODIϝιουͰ ࢠ$PSPVUJOF4DPQFΛ࡞੒

$PSPVUJOFͱ͸ fun main(args: Array<String>) = runBlocking { println("Start") launch {
delay(1000) println("1") } println("2") println("End") } Start 2 End 1

$PSPVUJOF %JTQBDIFST

$PSPVUJOF%JTQBDIFST 20 $PSPVUJOF͕Ͳͷ5ISFBEͰ࣮ߦ͞ΕΔ͔ ΛׂΓ౰ͯΔ࢓૊Έ

༻ҙ͞Ε͍ͯΔ%JTQBDIFST 21 εϨου ࠷దͳॲཧ .BJO ϝΠϯ UIΛมߋ͢Δؔ਺ɻLiveDataͷߋ৽ ౳ *0 IOʹ࠷దԽ
ωοτϫʔΫɺσΟεΫΞΫηεͳͲ %FGBVMU όοΫάϥ΢ϯυ  εϨουͷڞ༗ϓʔϧ CPUͷෛՙ͕େ͖͍ॲཧɻJSONղੳ ΍Ϧετͷฒͼସ͑౳

$PSPVUJOF%JTQBDIFST fun main(args: Array<String>) = runBlocking { withContext(Dispatchers.IO) { delay(1000)
println("IO: ${Thread.currentThread().id}") } println("Main: ${Thread.currentThread().id}") } IO: 11 Main: 1

$PSPVUJOF%JTQBDIFST fun main(args: Array<String>) = runBlocking { withContext(Dispatchers.IO) { println("IO:
${Thread.currentThread().id}") } println("Main: ${Thread.currentThread().id}") } IO: 11 Main: 1 $PSPVUJOF4DPQFͷUIJTMBVODI ϝιουͰࢠ$PSPVUJOF4DPQFΛ࡞੒ ͢Δ

4VTQFOE

TVTQFOE 25 தஅɺ࠶։Ͱ͖Δؔ਺ɻTVTQFOEؔ਺͸ DPSPVUJOFɺ΋͘͠͸ผͷTVTQFOEؔ਺ ͔Β͔͠ݺ΂ͳ͍

TVTQFOE suspend fun getData(): ApiResponse { return callApi() } fun
main(args: Array<String>) { getData() } Suspend function 'getData' should be called only from a coroutine or another suspend function

main(args: Array<String>) { getData() } Suspend function 'getData' should be called only from a coroutine or another suspend function ΤϥʔʹͳΔ

main(args: Array<String>) = runBlocking { getData() } DPSPVUJOFΛىಈͦ͠ͷதͰݺͿͱ Τϥʔ͕ൃੜ͠ͳ͍

࣮༻ྫ

7JFX.PEFMͰ࢖͏ fun callApi(name: String): UserResponseBody { val client = OkHttpClient()
val request = Request.Builder() .url("https://api.github.com/users/$name") .build() client.newCall(request).execute().use {response -> return Gson().fromJson(response.body?.string(), UserResponseBody::class.java) } } class MainViewModel : ViewModel() { val response = MutableLiveData<UserResponseBody>() val userName = MutableLiveData<String>() fun getUser() { viewModelScope.launch { response.value = callApi(userName.value ?: "") } } }

7JFX.PEFMͰ࢖͏ class MainViewModel : ViewModel() { val response = MutableLiveData<UserResponseBody>()
val userName = MutableLiveData<String>() fun getUser() { viewModelScope.launch { response.value = callApi(userName.value ?: "") } } } ϝΠϯεϨουͰΠϯλʔωοτΞΫηε ͢ΔͨΊΤϥʔʹͳΔ WJFX.PEFMͷϥΠϑαΠΫϧͰ؅ཧ͞ΕΔ WJFX.PEFM4DPQFͷ $PSPVUJOF#VJMEFSͰ$PSPVUJOFΛىಈ

ΤϥʔʹͳΒͳ͍Α͏ʹ͢Δ suspend fun callApi(name: String): UserResponseBody = withContext(Dispatchers.IO){ val client
= OkHttpClient() val request = Request.Builder() .url("https://api.github.com/users/$name") .build() client.newCall(request).execute().use {response -> Gson().fromJson(response.body?.string(), UserResponseBody::class.java) } } TVTQFOEؔ਺ʹ͢Δ %JTQBDIFST*0Ͱىಈ͢ΔΑ͏ʹࢦఆ

class MainViewModel : ViewModel() { val response = MutableLiveData<UserResponseBody>() val
userName = MutableLiveData<String>("sutetotanuki") val error = MutableLiveData<String>() fun getGithubUser() { viewModelScope.launch { try { response.value = callApi(userName.value ?: "") } catch (e: Throwable) { error.value = e.message } } } } Τϥʔॲཧ TVTQFOEؔ਺ͷΤϥʔ΋ USZDBUDIͰर͑Δ

ίʔϧόοΫؔ਺ $BMMCBDLΛ$PSPVUJOFͰͲ͏࣮૷͢Δͷ͔ Λ4USJQFͷ&QIFNFSBM,FZΛྫʹ঺հ ͠·͢

ίʔϧόοΫؔ਺ override suspend fun initSession() = suspendCoroutine<Unit> { con ->
CustomerSession.initCustomerSession( context, object : EphemeralKeyProvider { override fun createEphemeralKey( apiVersion: String, keyUpdateListener: EphemeralKeyUpdateListener ) { val ephemeralKeyBody = runBlocking { api.issueEphemeralKey(EphemeralKeyRequest(apiVersion)) } keyUpdateListener.onKeyUpdate(ephemeralKeyBody.string()) con.resume(Unit) } } ) }

4USJQFͷ &QIFNFSBM,FZ1SPWJEFS import androidx.annotation.Size interface EphemeralKeyProvider { fun createEphemeralKey( @Size(min
= 4) apiVersion: String, keyUpdateListener: EphemeralKeyUpdateListener ) }

4USJQFͷ &QIFNFSBM,FZ1SPWJEFS import androidx.annotation.Size interface EphemeralKeyProvider { fun createEphemeralKey( @Size(min
= 4) apiVersion: String, keyUpdateListener: EphemeralKeyUpdateListener ) } BQJ7FSTJPOΛ&QIFNFSBM,FZΛੜ੒͢ ΔαʔόʔαΠυͷ"1*ʹΘͨ͢ LFZ6QEBUF-JTUFOFSʹ"1*͕ੜ੒ͨ͠ &QIFNFSBM,FZΛ౉͢

ίʔϧόοΫؔ਺ suspend fun initSession() = suspendCoroutine<Unit> { con -> CustomerSession.initCustomerSession(
context, object : EphemeralKeyProvider { override fun createEphemeralKey( apiVersion: String, keyUpdateListener: EphemeralKeyUpdateListener ) { val ephemeralKeyBody = runBlocking { api.issueEphemeralKey(EphemeralKeyRequest(apiVersion)) } keyUpdateListener.onKeyUpdate(ephemeralKeyBody.string()) con.resume(Unit) } } ) } BQJ͕TVTQFOEؔ਺Ͱ࣮૷͞Ε͍ͯΔͷͰ SVO#MPDLJOHͰݺͼͩ͠ "1*ͷϨεϙϯεΛ-JTUFOFSʹઃఆ

ίʔϧόοΫؔ਺ suspend fun initSession() = suspendCoroutine<Unit> { con -> CustomerSession.initCustomerSession(
context, object : EphemeralKeyProvider { override fun createEphemeralKey( apiVersion: String, keyUpdateListener: EphemeralKeyUpdateListener ) { val ephemeralKeyBody = runBlocking { api.issueEphemeralKey(EphemeralKeyRequest(apiVersion)) } keyUpdateListener.onKeyUpdate(ephemeralKeyBody.string()) con.resume(Unit) } } ) } -JTUFOFSʹ஋Λ౉ͤͨͷͰ SFTVNF ෮ؼ ͢Δ

͝ਗ਼ௌ ͋Γ͕ͱ͏͍͟͝·ͨ͠

Kotlin Coroutine 基本的な使い方

Kotlin Coroutine 基本的な使い方

More Decks by sutetotanuki

Other Decks in Programming

Featured

Transcript