API koneksi aman

Setelah menemukan perangkat jarak jauh, fungsi handleIntent dipanggil, dan saatnya untuk mulai meneruskan data di antara klien. Bagian ini membahas empat langkah penting untuk mempertahankan koneksi yang aman:

• Membuka koneksi
• Menerima koneksi
• Mengirim dan menerima data
• Memutus koneksi

Membuka koneksi

Untuk membuka koneksi guna menerima data dari perangkat jarak jauh, gunakan objek peserta yang diterima sebelumnya dan tentukan CHANNEL_NAME:

participant
  .openConnection(CHANNEL_HELLO)
  .onFailure { /* handle failure */}
  .getOrNull()
  ?.let { connection ->
    connection.send("Hello, world".toByteArray(UTF_8)).onFailure { /* handle failure */}
  }

public void openConnection(Participant participant) {
  Futures.addCallback(
      participant.openConnectionFuture(CHANNEL_HELLO),
      new FutureCallback<RemoteConnection>() {
        @Override
        public void onSuccess(RemoteConnection remoteConnection) {
          // use remoteConnection object to pass data, e.g.:
          sendDataToRemoteConnection(remoteConnection);
        }

        @Override
        public void onFailure(Throwable t) {
          // handle error opening a remote connection
        }
      },
      mainExecutor);
}

private void sendDataToRemoteConnection(RemoteConnection remoteConnection) {
  Futures.addCallback(
      remoteConnection.sendFuture("Hello, world".getBytes()),
      new FutureCallback<Void>() {
        @Override
        public void onSuccess(Void result) {
          // data sent successfully
        }

        @Override
        public void onFailure(Throwable t) {
          // handle error
        }
      },
      mainExecutor);
}

Menerima, mengirim/menerima, dan menutup koneksi

Koneksi aman mengharuskan perangkat penerima untuk menerima koneksi masuk sebelum menerima data. Untuk menerima koneksi jarak jauh, gunakan snippet:

suspend fun acceptIncomingConnection(participant: Participant) {
  val connection = participant.acceptConnection(CHANNEL_HELLO).getOrThrow()
  connection.registerReceiver(
    object : ConnectionReceiver {
      override fun onMessageReceived(remoteConnection: RemoteConnection, payload: ByteArray) {
        displayMessage(payload.toString(UTF_8))
      }

      override fun onConnectionClosed(
        remoteConnection: RemoteConnection,
        error: Throwable?,
        reason: String?
      ) {
        // handle connection closure
      }
    }
  )
}

public void acceptIncomingConnection(Participant participant) {
  // Registers call back to accept incoming remote connection
  Futures.addCallback(
      participant.acceptConnectionFuture(CHANNEL_HELLO),
      new FutureCallback<>() {
        @Override
        public void onSuccess(RemoteConnection result) {
          receiveData(result);
        }

        @Override
        public void onFailure(Throwable t) {
          // handle connection error
        }
      },
      mainExecutor);
}

private void receiveData(RemoteConnection remoteConnection) {
  remoteConnection.registerReceiver(
      new ConnectionReceiver() {
        @Override
        public void onMessageReceived(RemoteConnection remoteConnection, byte[] payload) {
          displayMessage(new String(payload, UTF_8));
        }

        @Override
        public void onConnectionClosed(
            RemoteConnection remoteConnection,
            @Nullable Throwable error,
            @Nullable String reason) {
          // handle connection closure
        }
      });
}