如何用HMS Nearby Service给自己的App添加近距离数据传输功能

<!-- Required for Nearby Discovery and Nearby Transfer --> 
<uses-permission android:name="android.permission.BLUETOOTH" /> 
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />  
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />  
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> 
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> 
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 
<!-- Required for FILE payloads --> 
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Policy policy = Policy.POLICY_STAR; 
BroadcastOption broadcastOption = new BroadcastOption.Builder().setPolicy (policy).build();

private void doStartBroadcasting() {
  Policy policy = Policy.POLICY_STAR;
  BroadcastOption broadcastOption = new BroadcastOption.Builder().setPolicy(policy).build();
  Nearby.getDiscoveryEngine(getApplicationContext())
      .startBroadcasting(name, serviceId, connectCallback, broadcastOption)
      .addOnSuccessListener(
          new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void aVoid) {
              /* We are broadcasting. */
            }
          })
      .addOnFailureListener(
          new OnFailureListener() {
            @Override
            public void onFailure(Exception e) {
              /* Fail to start broadcasting. */
            }
          });
}

private void doStartScan() {
  Policy policy = Policy.POLICY_STAR;
  ScanOption scanOption = new ScanOption.Builder().setPolicy(policy).build();
  Nearby.getDiscoveryEngine(getApplicationContext())
      .startScan(serviceId, scanEndpointCallback, scanOption)
      .addOnSuccessListener(
          new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void aVoid) {
              /* Start scan success. */
            }
          })
      .addOnFailureListener(
          new OnFailureListener() {
            @Override
            public void onFailure(Exception e) {
              /* Fail to start scan. */
            }
          }); 
}

private ScanEndpointCallback scanEndpointCallback =
      new ScanEndpointCallback() {
        @Override
        public void onFound(String endpointId, ScanEndpointInfo discoveryEndpointInfo) {
          mEndpointId = endpointId;
          mDiscoveryEngine.requestConnect(myNameStr, mEndpointId, mConnCb);
        }
        @Override
        public void onLost(String endpointId) {
          Log.d(TAG, "Nearby Connection Demo app: Lost endpoint: " + endpointId);
        }
      };

private void doStartConnect(String name, String endpointId) throws RemoteException {
  Nearby.getDiscoveryEngine(getApplicationContext())
      .requestConnect(name, endpointId, connectCallback)
      .addOnSuccessListener(
          new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void aVoid) {
              /* Request success. */
            }
          })
      .addOnFailureListener(
          new OnFailureListener() {
            @Override
            public void onFailure(Exception e) {
              /* Fail to request connect. */
            }
          });
}

private final ConnectCallback connectCallback =
    new ConnectCallback() {
      @Override
      public void onEstablish(String endpointId, ConnectInfo connectInfo) {
        /* Accept the connection request without notifying user. */
        Nearby.getDiscoveryEngine(getApplicationContext())
.acceptConnect(endpointId, dataCallback);
      }
      @Override
      public void onResult(String endpointId, ConnectResult result) { 
        switch (result.getStatus().getStatusCode()) {
          case StatusCode.STATUS_SUCCESS:
            /* The connection was established successfully, we can exchange data. */ 
            break; 
          case StatusCode.STATUS_CONNECT_REJECTED: 
            /* The Connection was rejected. */
            break;  
          default:
            /* other unknown status code. */ 
        }  
      }
      @Override  
      public void onDisconnected(String endpointId) {
        /* The connection was disconneted. */
      } 
    };

@Override 
public void onEstablish(String endpointId, ConnectInfo connectInfo) { 
  AlertDialog.Builder builder = new AlertDialog.Builder(getApplicationContext());  
  builder.setTitle(connectInfo.getEndpointName() + " request connection") 
      .setMessage("Please confirm the match code is: " + connectInfo.getAuthCode()) 
      .setPositiveButton(
          "Accept",  
          (DialogInterface dialog, int which) -> 
              /* Accept the connection. */
              Nearby.getDiscoveryEngine(getApplicationContext()) 
                  .acceptConnect(endpointId, dataCallback))
      .setNegativeButton(
          "Reject",
          (DialogInterface dialog, int which) ->
              /* Reject the connection. */
              Nearby.getDiscoveryEngine(getApplicationContext())
                  .rejectConnect(endpointId))
      .setIcon(android.R.drawable.ic_dialog_alert);
  AlertDialog alert = builder.create();
  alert.show(); 
}

Data bytesData = Data.fromBytes(new byte[] {0xA, 0xA, 0xA, 0xA, 0xA});  
Nearby.getTransferEngine(getApplicationContext()).sendData(toEndpointId, bytesData);

static class BytesDataReceiver extends DataCallback { 
  @Override
  public void onReceived(String endpointId, Data data) {
    /* BYTES data is sent as a single block, so we can get complete data. */
    if (data.getType() == Data.Type.BYTES) {
      byte[] receivedBytes = data.asBytes();
    }
  }
  @Override
  public void onTransferUpdate(String endpointId, TransferStateUpdate update) {
    /* We will receive TRANSFER_STATE_SUCCESS update after onReceived() called. */
  }
}

File fileToSend = new File(getApplicationContext().getFilesDir(), "fileSample.txt");
try { 
  Data fileData = Data.fromFile(fileToSend);
  Nearby.getTransferEngine(getApplicationContext())
.sendData(endpointList, fileData);
} catch (FileNotFoundException e) { 
  /* Exception handle. */
}

ParcelFileDescriptor pfd = getContentResolver().openFileDescriptor(uri, "r");
Data fileData = Data.fromFile(pfd);

/* We can get the received file in the Download folder. */  
File payloadFile = fileData.asFile().asJavaFile();
)

URL url = new URL("https://developers.huawei.com"); 
Data streamData = Data.fromStream(url.openStream()); 
Nearby.getTransferEngine(getApplicationContext()).sendData(toEndpointId, streamData);

static class StreamDataReceiver extends DataCallback { 
  private final HashMap<Long, Data> incomingData = new HashMap<>();
  @Override
  public void onTransferUpdate(String endpointId, TransferStateUpdate update) {
    if (update.getStatus() == TransferStateUpdate.Status.TRANSFER_STATE_SUCCESS) {
      Data data = incomingData.get(update.getDataId());
      InputStream inputStream = data.asStream().asInputStream();
      /* Further processing... */
    }
  }
  @Override
  public void onReceived(String endpointId, Data data) {
    incomingData.put(data.getId(), data);
  } 
}