以 Device Discovery 和 Secure Connection API 為基礎， Sessions API 提供強大的抽象化機制，可打造順暢的跨裝置體驗 這點十分重要工作階段代表可滿足下列條件的應用程式使用者體驗 。
Sessions API 也是以個人與共同為核心打造而成 工作階段轉移和工作階段共用用途代表的體驗 。下圖說明高階的工作階段：
建立及轉移工作階段
Sessions API 可區分來源裝置和接收裝置。來源裝置會建立工作階段，並搜尋 可處理工作階段的裝置。來源裝置的使用者 會從系統對話方塊提供的清單中選取裝置。使用者 選取接收裝置，系統會轉移及移除來源工作階段 來自原始裝置
如要轉移工作階段，請先使用下列方法建立工作階段： 參數：
- 應用程式工作階段標記，讓您用來區分 在應用程式中的多個工作階段之間來回切換
然後使用下列參數啟動轉移程序：
DeviceFilter，用於篩選可處理工作階段的裝置- 實作
OriginatingSessionStateCallback的回呼物件
在原始裝置上，使用下方範例建立工作階段：
private val HELLO_WORLD_TRANSFER_ACTION = "hello_world_transfer"
private lateinit var originatingSession: OriginatingSession
private lateinit var sessions: Sessions
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
sessions = Sessions.create(context = this)
}
suspend fun transferSession() {
val sessionId =
sessions.createSession(
ApplicationSessionTag("hello_world_transfer"),
)
originatingSession =
sessions.transferSession(
sessionId,
StartComponentRequest.Builder()
.setAction(HELLO_WORLD_TRANSFER_ACTION)
.setReason("Transfer reason here")
.build(),
emptyList(),
HelloWorldTransferSessionStateCallback()
)
}
private static final String HELLO_WORLD_TRANSFER_ACTION = "hello_world_transfer";
private OriginatingSession originatingSession;
private Sessions sessions;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sessions = Sessions.create(/* context= */ this);
}
public void transferSession() {
SessionId sessionId = sessions.createSession(new ApplicationSessionTag("hello_world_transfer"));
ListenableFuture<OriginatingSession> originatingSessionFuture =
sessions.transferSessionFuture(
sessionId,
new StartComponentRequest.Builder()
.setAction(HELLO_WORLD_TRANSFER_ACTION)
.setReason("Transfer reason here")
.build(),
Collections.emptyList(),
new HelloWorldTransferSessionStateCallback());
Futures.addCallback(
originatingSessionFuture,
new FutureCallback<>() {
@Override
public void onSuccess(OriginatingSession result) {
// Do nothing, handled in HelloWorldTransferSessionStateCallback
originatingSession = result;
}
@Override
public void onFailure(Throwable t) {
Log.d(TAG, "onFailure called for transferSessionFuture", t);
}
},
mainExecutor);
}
接著，請在原始裝置上定義工作階段回呼：
private inner class HelloWorldTransferSessionStateCallback : OriginatingSessionStateCallback {
override fun onConnected(sessionId: SessionId) {
val startupRemoteConnection = originatingSession.getStartupRemoteConnection()
lifecycleScope.launchWhenResumed {
startupRemoteConnection.send("hello, world".toByteArray(UTF_8))
startupRemoteConnection.registerReceiver(
object : SessionConnectionReceiver {
override fun onMessageReceived(participant: SessionParticipant, payload: ByteArray) {
val ok = payload.contentEquals("ok".toByteArray(UTF_8))
Log.d(TAG, "Session transfer initialized. ok=$ok")
}
}
)
}
}
override fun onSessionTransferred(sessionId: SessionId) {
Log.d(TAG, "Transfer done.")
}
override fun onTransferFailure(sessionId: SessionId, exception: SessionException) {
// Handle error
}
}
private class HelloWorldTransferSessionStateCallback implements OriginatingSessionStateCallback {
@Override
public void onConnected(SessionId sessionId) {
SessionRemoteConnection startupRemoteConnection =
originatingSession.getStartupRemoteConnection();
Futures.addCallback(
startupRemoteConnection.sendFuture("hello, world".getBytes()),
new FutureCallback<>() {
@Override
public void onSuccess(Void result) {
Log.d(TAG, "Successfully sent initialization message");
}
@Override
public void onFailure(Throwable t) {
Log.d(TAG, "Failed to send initialization message", t);
}
},
mainExecutor);
}
@Override
public void onSessionTransferred(SessionId sessionId) {
Log.d(TAG, "Transfer done.");
}
@Override
public void onTransferFailure(SessionId sessionId, SessionException exception) {
// Handle error
}
}
開始工作階段轉移後，接收端裝置會收到回呼
在 onNewIntent(intent: Intent) 方法中定義。意圖資料包含所有項目
轉移工作階段所需的資訊。
如要在接收裝置上完成轉移作業，請按照下列步驟操作：
private lateinit var sessions: Sessions
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
sessions = Sessions.create(context = this)
}
override fun onNewIntent(intent: Intent) {
super.onNewIntent(intent)
lifecycleScope.launchWhenResumed {
val receivingSession =
sessions.getReceivingSession(intent, HelloWorldReceivingSessionStateCallback())
// Get info from receiving device and init.
val startupRemoteConnection = receivingSession.getStartupRemoteConnection()
startupRemoteConnection.registerReceiver(
object : SessionConnectionReceiver {
override fun onMessageReceived(participant: SessionParticipant, payload: ByteArray) {
lifecycleScope.launchWhenResumed {
val transferInfo = String(payload)
startupRemoteConnection.send("ok".toByteArray(UTF_8))
// Complete transfer.
Log.d(TAG, "Transfer info: " + transferInfo)
receivingSession.onComplete()
}
}
}
)
}
}
private inner class HelloWorldReceivingSessionStateCallback : ReceivingSessionStateCallback {
override fun onTransferFailure(sessionId: SessionId, exception: SessionException) {
// Handle error
}
}
private Sessions sessions;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sessions = Sessions.create(/* context= */ this);
}
@Override
public void onNewIntent(Intent intent) {
super.onNewIntent(intent);
ListenableFuture<ReceivingSession> receivingSessionFuture =
sessions.getReceivingSessionFuture(intent, new HelloWorldReceivingSessionStateCallback());
ListenableFuture<Void> registerReceiverFuture =
Futures.transform(
receivingSessionFuture,
receivingSession -> {
SessionRemoteConnection startupRemoteConnection =
receivingSession.getStartupRemoteConnection();
SessionConnectionReceiver receiver =
(participant, payload) -> {
Log.d(
TAG,
"Successfully received initialization message of size: " + payload.length);
applicationInitialization(receivingSession, payload);
};
startupRemoteConnection.registerReceiver(receiver);
return null;
},
mainExecutor);
Futures.addCallback(
registerReceiverFuture,
new FutureCallback<Void>() {
@Override
public void onSuccess(Void unused) {
Log.d(TAG, "Connection receiver registerd successfully");
}
@Override
public void onFailure(Throwable t) {
Log.w(TAG, "Failed to register connection receiver", t);
}
},
mainExecutor);
}
private void applicationInitialization(ReceivingSession receivingSession, byte[] initMessage) {
ListenableFuture<SessionId> disconnectFuture =
Futures.transform(
receivingSession.onCompleteFuture(),
sessionId -> {
Log.d(TAG, "Succeeded to complete receive transfer for: " + sessionId);
return sessionId;
},
mainExecutor);
Futures.addCallback(
disconnectFuture,
new FutureCallback<SessionId>() {
@Override
public void onSuccess(SessionId result) {
Log.d(TAG, "Succeeded to remove the old session: " + result);
}
@Override
public void onFailure(Throwable t) {
Log.d(TAG, "Failed to remove the old session, which is now orphaned", t);
}
},
mainExecutor);
}
private static class HelloWorldReceivingSessionStateCallback
implements ReceivingSessionStateCallback {
@Override
public void onTransferFailure(SessionId sessionId, SessionException exception) {
// Handle error
}
}
接收裝置後，即可繼續提供使用者體驗。
共用工作階段
分享課程即可邀請附近的其他人加入群組 操作起來，例如：
- 直接與朋友的車分享地圖位置。
- 與您騎單車的對象分享週日單車路線。
- 即使手機不在身邊，也能收集團體美食訂單的物品。
- 票選下一部電視節目，讓大家一起觀看。
當使用者選擇與其他裝置共用工作階段時，來源 裝置搜尋並顯示可加入工作階段的裝置，以及 使用者選取接收裝置。應用程式會提示使用者 接收裝置，以便從來源裝置加入工作階段。接收 裝置就會獲得次要工作階段，與裝置上的工作階段互動 。應用程式也可以將其他參與者新增至 。
共用工作階段的程序與轉移工作階段類似
而是呼叫 shareSession，而不是呼叫 transferSession。另一個
差異在於工作階段狀態回呼方法。
// Originating side.
private val HELLO_WORLD_SHARE_ACTION = "hello_world_share"
private var activePrimarySession: PrimarySession? = null
private lateinit var sessions: Sessions
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
sessions = Sessions.create(context = this)
}
suspend fun shareSession() {
val sessionId = sessions.createSession(ApplicationSessionTag("hello_world_share"))
activePrimarySession =
sessions.shareSession(
sessionId,
StartComponentRequest.Builder()
.setAction(HELLO_WORLD_SHARE_ACTION)
.setReason("Share reason here")
.build(),
emptyList(),
HelloWorldShareSessionStateCallback(),
)
}
private inner class HelloWorldShareSessionStateCallback : PrimarySessionStateCallback {
override fun onShareInitiated(sessionId: SessionId, numPotentialParticipants: Int) {
// Custom logic here for when n devices can potentially join.
// e.g. if there were 0, cancel/error if desired,
// if non-0 maybe spin until numPotentialParticipants join etc.
}
override fun onParticipantJoined(sessionId: SessionId, participant: SessionParticipant) {
// Custom join logic here
lifecycleScope.launchWhenResumed {
// Example logic: send only to the participant who just joined.
val connection =
checkNotNull(activePrimarySession).getSecondaryRemoteConnectionForParticipant(participant)
connection.send("Initing hello, world.".toByteArray(UTF_8))
connection.registerReceiver(
object : SessionConnectionReceiver {
override fun onMessageReceived(participant: SessionParticipant, payload: ByteArray) {
val ok = payload.contentEquals("ok".toByteArray(UTF_8))
Log.d(TAG, "Session share initialized. ok=$ok")
// Example logic: broadcast to all participants, including the one
// that just joined.
lifecycleScope.launchWhenResumed {
checkNotNull(activePrimarySession)
.broadcastToSecondaries("hello, all.".toByteArray(UTF_8))
}
}
}
)
}
}
override fun onParticipantDeparted(sessionId: SessionId, participant: SessionParticipant) {
// Custom leave logic here.
}
override fun onPrimarySessionCleanup(sessionId: SessionId) {
// Custom cleanup logic here.
activePrimarySession = null
}
override fun onShareFailureWithParticipant(
sessionId: SessionId,
exception: SessionException,
participant: SessionParticipant
) {
// Handle error
}
}
// Originating side
private static final String HELLO_WORLD_SHARE_ACTION = "hello_world_share";
@Nullable private PrimarySession activePrimarySession = null;
private Sessions sessions;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sessions = Sessions.create(/* context= */ this);
}
private void shareSession() {
SessionId sessionId = sessions.createSession(new ApplicationSessionTag("hello_world_share"));
ListenableFuture<PrimarySession> shareSessionFuture =
sessions.shareSessionFuture(
sessionId,
new StartComponentRequest.Builder()
.setAction(HELLO_WORLD_SHARE_ACTION)
.setReason("Share reason here")
.build(),
Collections.emptyList(),
new HelloWorldShareSessionStateCallback());
Futures.addCallback(
shareSessionFuture,
new FutureCallback<PrimarySession>() {
@Override
public void onSuccess(PrimarySession primarySession) {
activePrimarySession = primarySession;
}
@Override
public void onFailure(Throwable t) {
Log.d(TAG, "Failed to share session", t);
}
},
mainExecutor);
}
private class HelloWorldShareSessionStateCallback implements PrimarySessionStateCallback {
@Override
public void onShareInitiated(SessionId sessionId, int numPotentialParticipants) {
// Custom logic here for when n devices can potentially join.
// e.g. if there were 0, cancel/error if desired,
// if non-0 maybe spin until numPotentialParticipants join etc.
}
@Override
public void onParticipantJoined(SessionId sessionId, SessionParticipant participant) {
PrimarySession joinedSession = activePrimarySession;
if (joinedSession == null) {
return;
}
SessionRemoteConnection connection =
joinedSession.getSecondaryRemoteConnectionForParticipant(participant);
Futures.addCallback(
connection.sendFuture("Initiating hello, world.".getBytes()),
new FutureCallback<Void>() {
@Override
public void onSuccess(Void result) {
// Send successful.
}
@Override
public void onFailure(Throwable t) {
// Failed to send.
}
},
mainExecutor);
connection.registerReceiver(
new SessionConnectionReceiver() {
@Override
public void onMessageReceived(SessionParticipant participant, byte[] payload) {
boolean ok = new String(payload, UTF_8).equals("ok");
Log.d(TAG, "Session share initialized. ok=" + ok);
// Example logic: broadcast to all participants, including the one
// that just joined.
Futures.addCallback(
joinedSession.broadcastToSecondariesFuture("hello, all.".getBytes()),
new FutureCallback<Void>() {
@Override
public void onSuccess(Void result) {
// Broadcast successful.
}
@Override
public void onFailure(Throwable t) {
// Failed to broadcast hello world.
}
},
mainExecutor);
}
});
}
@Override
public void onParticipantDeparted(SessionId sessionId, SessionParticipant participant) {
// Custom leave logic here.
}
@Override
public void onPrimarySessionCleanup(SessionId sessionId) {
// Custom cleanup logic here.
activePrimarySession = null;
}
@Override
public void onShareFailureWithParticipant(
SessionId sessionId, SessionException exception, SessionParticipant participant) {
// Custom error handling logic here.
}
}
在接收端：
// Receiving side.
override fun onNewIntent(intent: Intent) {
super.onNewIntent(intent)
lifecycleScope.launchWhenResumed {
val secondarySession =
sessions.getSecondarySession(intent, HelloWorldSecondaryShareSessionStateCallback())
val remoteConnection = secondarySession.getDefaultRemoteConnection()
remoteConnection.registerReceiver(
object : SessionConnectionReceiver {
override fun onMessageReceived(participant: SessionParticipant, payload: ByteArray) {
Log.d(TAG, "Payload received: ${String(payload)}")
}
}
)
}
}
private inner class HelloWorldSecondaryShareSessionStateCallback : SecondarySessionStateCallback {
override fun onSecondarySessionCleanup(sessionId: SessionId) {
// Custom cleanup logic here.
}
}
// Receiving side.
@Override
public void onNewIntent(Intent intent) {
super.onNewIntent(intent);
sessions = Sessions.create(this);
ListenableFuture<SecondarySession> secondarySessionFuture =
sessions.getSecondarySessionFuture(
intent, new HelloWorldSecondaryShareSessionStateCallback());
Futures.addCallback(
secondarySessionFuture,
new FutureCallback<SecondarySession>() {
@Override
public void onSuccess(SecondarySession secondarySession) {
SessionRemoteConnection remoteConnection =
secondarySession.getDefaultRemoteConnection();
remoteConnection.registerReceiver(
new SessionConnectionReceiver() {
@Override
public void onMessageReceived(SessionParticipant participant, byte[] payload) {
Log.d(TAG, "Payload received: " + new String(payload, UTF_8));
}
});
}
@Override
public void onFailure(Throwable t) {
// Handle error.
}
},
mainExecutor);
}
private static class HelloWorldSecondaryShareSessionStateCallback
implements SecondarySessionStateCallback {
@Override
public void onSecondarySessionCleanup(SessionId sessionId) {
// Custom cleanup logic here.
}
}