Tin nhắn ngắn

Người dùng có thể phát hành và đăng ký thông báo thông qua API NearbyConnections của Android. Người dùng Nearby Messages có thể điều chỉnh thiết kế hiện tại cho phù hợp với Nearby Connections thông qua các mẫu bên dưới. Để biết thêm thông tin chi tiết về cách sử dụng tính năng Kết nối lân cận, vui lòng tham khảo bài viết Tổng quan về Nearby Connections API.

Tính năng Kết nối lân cận cho phép ứng dụng gửi dữ liệu trong vòng 131 byte mà không cần thiết lập kết nối với thiết bị từ xa. Vui lòng tham khảo quy trình bên dưới để biết cách chuyển tin nhắn trong phạm vi 131 byte.

Nhà xuất bản

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();
}

Người đăng ký

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();
}

Tin nhắn dài

Đối với các tin nhắn lớn hơn 131 byte, bạn cần thiết lập kết nối giữa các thiết bị để chuyển tin nhắn. Vui lòng tham khảo quy trình bên dưới để biết cách chuyển dữ liệu lớn bằng tính năng Kết nối lân cận.

Nhà xuất bản

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();
}

Người đăng ký

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();
}