ข้อความสั้น

ผู้ใช้สามารถเผยแพร่และสมัครรับข้อความผ่าน API NearbyConnections ได้ ผู้ใช้ข้อความใกล้เคียงสามารถปรับการออกแบบปัจจุบันของตนเป็นการเชื่อมต่อใกล้เคียงผ่านตัวอย่างด้านล่างนี้ สำหรับการใช้งานโดยละเอียดเกี่ยวกับการเชื่อมต่อใกล้เคียง โปรดดูภาพรวมของ API การเชื่อมต่อใกล้เคียง

การเชื่อมต่อใกล้เคียงช่วยให้ไคลเอ็นต์ส่งข้อมูลภายใน 131 ไบต์ได้โดยไม่ต้องเชื่อมต่อกับอุปกรณ์ระยะไกล โปรดดูขั้นตอนด้านล่างเกี่ยวกับวิธีโอนข้อความภายใน 131 ไบต์

ผู้เผยแพร่โฆษณา

private void startPublishing() {
  // Using the default advertising option is enough since  connecting is not required.
  AdvertisingOptions advertisingOptions = new AdvertisingOptions.Builder().build();
  Nearby.getConnectionsClient(context)
      .startAdvertising(getMessagesInBytes(), SERVICE_ID, connectionLifecycleCallback, advertisingOptions)
      .addOnSuccessListener(
          (Void unused) -> {
            // We're advertising!
          })
      .addOnFailureListener(
          (Exception e) -> {
            // We were unable to start advertising.
          });
}

// To manage incoming connections from the subscriber.
// In this flow since we are not establishing connections between the two devices, we could
// ignore the implementation.
private final ConnectionLifecycleCallback connectionLifecycleCallback =
    new ConnectionLifecycleCallback() {
      @Override
      public void onConnectionInitiated(String endpointId, ConnectionInfo connectionInfo) {}

      @Override
      public void onConnectionResult(String endpointId, ConnectionResolution result) {}

      @Override
      public void onDisconnected(String endpointId) {}
    };

private void stopPublishing() {
  // Stop advertising when done.
  Nearby.getConnectionsClient(context).stopAdvertising();
  Nearby.getConnectionsClient(context).stopAllEndpoints();
}

ผู้สมัครใช้บริการ

private void startSubscription() {
  // Using the default discovery option is enough since connection is not required.
  DiscoveryOptions discoveryOptions = new DiscoveryOptions.Builder().build();
  Nearby.getConnectionsClient(context)
      // The SERVICE_ID value must uniquely identify your app.
      // As a best practice, use the package name of your app
      // (for example, com.google.example.myapp).
      .startDiscovery(SERVICE_ID, endpointDiscoveryCallback, discoveryOptions)
      .addOnSuccessListener(
          (Void unused) -> {
            // We're discovering!
          })
      .addOnFailureListener(
          (Exception e) -> {
            // We're unable to start discovering.
          });
}

private final EndpointDiscoveryCallback endpointDiscoveryCallback =
    new EndpointDiscoveryCallback() {
      @Override
      public void onEndpointFound(String endpointId, DiscoveredEndpointInfo info) {
        // A remote advertising endpoint is found.
        // To retrieve the published message data.
        byte[] message = info.getEndpointInfo();
      }

      @Override
      public void onEndpointLost(String endpointId) {
        // A previously discovered endpoint has gone away.
      }
    };

private void stopSubscription() {
  // Stop discovery when the subscription is done.
  Nearby.getConnectionsClient(context).stopDiscovery();
  Nearby.getConnectionsClient(context).stopAllEndpoints();
}

ข้อความขนาดยาว

สำหรับข้อความที่มีขนาดใหญ่กว่า 131 ไบต์ จะต้องทำการเชื่อมต่อระหว่างอุปกรณ์เพื่อโอนข้อความ โปรดดูขั้นตอนด้านล่างเกี่ยวกับวิธีโอนข้อมูลขนาดใหญ่โดยใช้การเชื่อมต่อใกล้เคียง

ผู้เผยแพร่โฆษณา

private void startPublishing() {
  // Using P2P strategy for 1:1 connection.
  AdvertisingOptions advertisingOptions =
      new AdvertisingOptions.Builder().setStrategy(Strategy.P2P_POINT_TO_POINT).build();
  Nearby.getConnectionsClient(context)
      .startAdvertising(
          getLocalUserName(), SERVICE_ID, connectionLifecycleCallback, advertisingOptions)
      .addOnSuccessListener(
          (Void unused) -> {
            // We're advertising!
          })
      .addOnFailureListener(
          (Exception e) -> {
            // We were unable to start advertising.
          });
}

private final ConnectionLifecycleCallback connectionLifecycleCallback =
    new ConnectionLifecycleCallback() {
      @Override
      public void onConnectionInitiated(String endpointId, ConnectionInfo connectionInfo) {
        // Automatically accept the connection on both sides.
        Nearby.getConnectionsClient(context).acceptConnection(endpointId, payloadCallback);
      }

      @Override
      public void onConnectionResult(String endpointId, ConnectionResolution result) {
        switch (result.getStatus().getStatusCode()) {
          case ConnectionsStatusCodes.STATUS_OK:
            // We're connected! Can now start sending and receiving data.
            Payload bytesPayload = Payload.fromBytes(DATA_TO_BE_SENT);
            Nearby.getConnectionsClient(context).sendPayload(endpointId, bytesPayload);
            break;
          case ConnectionsStatusCodes.STATUS_CONNECTION_REJECTED:
            // The connection was rejected by one or both sides.
            break;
          case ConnectionsStatusCodes.STATUS_ERROR:
            // The connection broke before it was able to be accepted.
            break;
          default:
            // Unknown status code
        }
      }

      @Override
      public void onDisconnected(String endpointId) {
        // We've been disconnected from this endpoint. No more data can be
        // sent or received.
      }
    };

private void stopPublishing() {
  // Stop advertising when done.
  Nearby.getConnectionsClient(context).stopAdvertising();
  Nearby.getConnectionsClient(context).stopAllEndpoints();
}

ผู้สมัครใช้บริการ

private void startSubscription() {
  DiscoveryOptions discoveryOptions =
      new DiscoveryOptions.Builder().setStrategy(Strategy.P2P_POINT_TO_POINT).build();
  Nearby.getConnectionsClient(context)
      .startDiscovery(SERVICE_ID, endpointDiscoveryCallback, discoveryOptions)
      .addOnSuccessListener(
          (Void unused) -> {
            // We're discovering!
          })
      .addOnFailureListener(
          (Exception e) -> {
            // We're unable to start discovering.
          });
}

private final EndpointDiscoveryCallback endpointDiscoveryCallback =
    new EndpointDiscoveryCallback() {
      @Override
      public void onEndpointFound(String endpointId, DiscoveredEndpointInfo info) {
        // An endpoint was found. We request a connection to it.
        Nearby.getConnectionsClient(context)
            .requestConnection(getLocalUserName(), endpointId, connectionLifecycleCallback)
            .addOnSuccessListener(
                (Void unused) -> {
                  // We successfully requested a connection. Now both sides
                  // must accept before the connection is established.
                })
            .addOnFailureListener(
                (Exception e) -> {
                  // Nearby Connections failed to request the connection.
                });
      }

      @Override
      public void onEndpointLost(String endpointId) {
        // A previously discovered endpoint has gone away.
      }
    };

private final ConnectionLifecycleCallback connectionLifecycleCallback =
    new ConnectionLifecycleCallback() {
      @Override
      public void onConnectionInitiated(String endpointId, ConnectionInfo connectionInfo) {
        // Automatically accept the connection on both sides.
        Nearby.getConnectionsClient(context).acceptConnection(endpointId, payloadCallback);
      }

      @Override
      public void onConnectionResult(String endpointId, ConnectionResolution result) {
        switch (result.getStatus().getStatusCode()) {
          case ConnectionsStatusCodes.STATUS_OK:
            // We're connected! Can now start sending and receiving data.
            break;
          case ConnectionsStatusCodes.STATUS_CONNECTION_REJECTED:
            // The connection was rejected by one or both sides.
            break;
          case ConnectionsStatusCodes.STATUS_ERROR:
            // The connection broke before it was able to be accepted.
            break;
          default:
            // Unknown status code
        }
      }

      @Override
      public void onDisconnected(String endpointId) {
        // We've been disconnected from this endpoint. No more data can be
        // sent or received.
      }
    };

static class ReceiveBytesPayloadListener extends PayloadCallback {
  @Override
  public void onPayloadReceived(String endpointId, Payload payload) {
    // This always gets the full data of the payload. Is null if it's not a BYTES payload.
    if (payload.getType() == Payload.Type.BYTES) {
      byte[] receivedBytes = payload.asBytes();
    }
  }

  @Override
  public void onPayloadTransferUpdate(String endpointId, PayloadTransferUpdate update) {
    // Bytes payloads are sent as a single chunk, so you'll receive a SUCCESS update immediately
    // after the call to onPayloadReceived().
  }
}

private void stopSubscription() {
  // Stop discovery when the subscription is done.
  Nearby.getConnectionsClient(context).stopDiscovery();
  Nearby.getConnectionsClient(context).stopAllEndpoints();
}