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针对 Android Wear 应用程序的 Bluemix IoT 实时仪表板

前提条件

Android 方面：

安装 Android Studio：https://developer.android.com/sdk/index.html
一个 Android 移动设备
一个 Android 手表

IBM Bluemix 方面：

一个 IBMBluemix 帐户

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创建一个新的 Android Wear 项目

首先，创建一个新的 Android 项目 (File->New->New Project)。

在向导中，键入“HeartRate”作为应用程序名称并选择您的项目所在的位置。

单击“Next”，选择“Phone and Tablet”和“Wear”，然后根据您的设备选择最低限度的 SDK。

单击“Next”，为移动应用程序选择“Blank Activity”。

单击“Next”，在 Activity Name 字段中键入“HeartRateMobileActivity”。

单击“Next”，为 Wear 应用程序选择“Blank Wear Activity”。

单击“Next”，在 Activity Name 字段中键入“HeartRateWearActivity”。

单击“Finish”。

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开发基本的可穿戴设备应用程序

权限

确保“mobile”和“wear”清单文件具有“BODY_SENSOR”权限：

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.ibm.hcs.heartrate" >  <uses-permission android:name="android.permission.BODY_SENSORS" /> …

更新可穿戴设备活动

在“wear”string.xml 文件中添加一个标签：

<string name="heartRateText">Heart Rate : N/A</string>

打开 Wear 的布局“round_activity_heart_rate_wear.xml”，然后使用“heartRateTextView”更改“id”字段，并使用 “@string/heartRateText”更改“text”字段。

打开“HeartRateWearActivity”字段并更改“onCreate”函数。

@Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_heart_rate_wear);  final WatchViewStub stub = (WatchViewStub) findViewById(R.id.watch_view_stub);  stub.setOnLayoutInflatedListener(new WatchViewStub.OnLayoutInflatedListener() {  @Override  public void onLayoutInflated(WatchViewStub stub) {  mTextView = (TextView) stub.findViewById(R.id.heartRateTextView);  }  }); }

创建一个新服务

创建一个名为“HeartRateWearService”的服务，验证清单文件：

<service android:name=".HeartRateWearService">

使用以下代码替换生成的文件：

点击查看代码清单

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public class HeartRateWearService extends Service implements SensorEventListener{  private SensorManager sensorManager;  private Sensor heartRateSensor;  private ScheduledExecutorService heartRateScheduler;  public HeartRateWearService() {  }   @Override  public void onCreate() {  super.onCreate();  getHeartRateValues();  }   private void getHeartRateValues() {  sensorManager = ((SensorManager) getSystemService(SENSOR_SERVICE));  heartRateSensor = sensorManager.getDefaultSensor(Sensor.TYPE_HEART_RATE);  if (heartRateSensor != null) {  heartRateScheduler = Executors.newScheduledThreadPool(1);  heartRateScheduler.scheduleAtFixedRate(  new Runnable() {  @Override  public void run() {  sensorManager.registerListener(HeartRateWearService.this, heartRateSensor, SensorManager.SENSOR_DELAY_NORMAL);  try {  Thread.sleep(10000);  } catch (InterruptedException e) {  }  sensorManager.unregisterListener(HeartRateWearService.this,heartRateSensor);  }  }, 3, 15, TimeUnit.SECONDS);  }  }   @Override  public IBinder onBind(Intent intent) {  return null;  }   @Override  public void onDestroy() {  if (sensorManager != null)  sensorManager.unregisterListener(this);  heartRateScheduler.shutdown();   super.onDestroy();  }   @Override  public void onSensorChanged(SensorEvent event) {  // sends an Intent to the Activity   Intent intent = new Intent();  intent.setAction("heartRateAction");  intent.putExtra("HeartRate", event.values[0]);  sendBroadcast(intent);  }    @Override  public void onAccuracyChanged(Sensor sensor, int accuracy) {  }

显示进行活动时的心率

打开“HeartRateWearActivity”文件，添加此属性：

private HeartRateBroadcastReceiver heartRateBroadcastReceiver;

添加此内部类：

private class HeartRateBroadcastReceiver extends BroadcastReceiver {  @Override  public void onReceive(Context arg0, Intent arg1) {  // ahr  Log.v(this.getClass().getName(), "Value Recieved");  if (arg1.getAction().equals("heartRateAction")) {  float hr = arg1.getFloatExtra("HeartRate", 0);  if (HeartRateWearActivity.this.mTextView != null) {  HeartRateWearActivity.this.mTextView.setText("Heart Rate : " + hr);  }  }  }  }

添加以下方法：

@Override protected void onStart() {  // initialize the broadcast recieiver  heartRateBroadcastReceiver = new HeartRateBroadcastReceiver();  IntentFilter intentFilter = new IntentFilter();  intentFilter.addAction("heartRateAction");  registerReceiver(heartRateBroadcastReceiver, intentFilter);   // start HeartRateWearService  startService(new Intent(this, HeartRateWearService.class));  super.onStart(); }  @Override protected void onStop() {  unregisterReceiver(heartRateBroadcastReceiver);  stopService(new Intent(this, HeartRateWearService.class));  super.onStop(); }

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将心率发送给移动应用程序

更新 Wear 应用程序以发送心率

打开“HeartRateWearService”，添加属性：

private GoogleApiClient googleApiClient; private ExecutorService executorService;

在“onCreate”函数中初始化 executorService：

@Override public void onCreate() {  …  …  executorService = Executors.newCachedThreadPool(); }

添加以下函数：

点击查看代码清单

关闭 [x]

private boolean isConnected() {  if (googleApiClient == null)  googleApiClient = new GoogleApiClient.Builder(this.getApplication().getApplicationContext()).addApi(Wearable.API).build();   if (googleApiClient.isConnected()) {  return true;  }   ConnectionResult result = googleApiClient.blockingConnect(15000, TimeUnit.MILLISECONDS);  return result.isSuccess(); }  private void sendToMobile(final SensorEvent event) {  executorService.submit(new Runnable() {  @Override  public void run() {    PutDataMapRequest dataMap = PutDataMapRequest.create("/sensor/heartRate");  dataMap.getDataMap().putLong("timestamp", event.timestamp);  dataMap.getDataMap().putFloat("value", event.values[0]);  PutDataRequest putDataRequest = dataMap.asPutDataRequest();  if (isConnected()) {  Wearable.DataApi.putDataItem(googleApiClient, putDataRequest).setResultCallback(new ResultCallback<DataApi.DataItemResult>() {  @Override  public void onResult(DataApi.DataItemResult dataItemResult) {  Log.v(this.getClass().getName(), "Sending heartRate: " + dataItemResult.getStatus().isSuccess());  }  });  }  }  });  }

在“onSensorChanged”函数中添加此指令：

@Override public void onSensorChanged(SensorEvent event) {  …  …  sendToMobile(event); }

更新移动活动

在“mobile”string.xml 文件中添加一个标签：

<string name="heartRateText">Heart Rate : N/A</string>

打开移动布局“activity_heart_rate_mobile.xml”，然后使用“heartRateTextView”更改“id”字段，并使用 “@string/heartRateText”更改“text”字段。

创建一个新的移动服务

在移动模块中创建一个新服务“HeartRateMobileWearableListenerService”。

更新移动清单：

<service android:name=".HeartRateMobileWearableListenerService" >  <intent-filter>  <action android:name="com.google.android.gms.wearable.BIND_LISTENER"/>  </intent-filter>  </service>

更改“HeartRateMobileWearableListenerService”代码：

public class HeartRateMobileWearableListenerService extends WearableListenerService {  @Override  public void onDataChanged(DataEventBuffer dataEvents) {  Log.d(this.getClass().getName(), "onDataChanged()");  for (DataEvent dataEvent : dataEvents) {  if (dataEvent.getType() == DataEvent.TYPE_CHANGED) {  DataItem dataItem = dataEvent.getDataItem();  Uri uri = dataItem.getUri();  String path = uri.getPath();  if (path.equals("/sensor/heartRate")) {  DataMap map = DataMapItem.fromDataItem(dataItem).getDataMap();  long timestamp = map.getLong("timestamp");  float value = map.getFloat("value");  Intent intent = new Intent();  intent.setAction("heartRateAction");  intent.putExtra("HeartRate", value);  sendBroadcast(intent);  }  }  }  } }

显示进行移动活动时的心率

打开“HeartRateMobileActivity”，添加此属性：

private HeartRateBroadcastReceiver heartRateBroadcastReceiver;

添加此内部类：

点击查看代码清单

关闭 [x]

private class HeartRateBroadcastReceiver extends BroadcastReceiver {  @Override  public void onReceive(Context arg0, Intent arg1) {  // ahr  Log.v(this.getClass().getName(), "Value Recieved");  if (arg1.getAction().equals("heartRateAction")) {  float hr = arg1.getFloatExtra("HeartRate", 0);  ((TextView)HeartRateMobileActivity.this.findViewById(R.id.heartRateTextView)).setText("Heart Rate : " + hr);  }  } }

添加“onStart”函数：

@Override protected void onStart() {  super.onStart();  // ahr  heartRateBroadcastReceiver = new HeartRateBroadcastReceiver();  IntentFilter intentFilter = new IntentFilter();  intentFilter.addAction("heartRateAction");  registerReceiver(heartRateBroadcastReceiver, intentFilter); }

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向 IoT Fundation 发布心率

在 IoT Fundation 服务中创建一个设备

连接到您的 IBM Bluemix 帐户
在 Catalog 选项卡中，选择“Internet of Things Fundation Starter”
在 Name 字段中输入“HeartRate”并单击“Create”按钮

在 Catalog 选项卡中，选择“Internet of Things”
单击“Create”按钮
启动 Internet of Things Foundation 仪表板
选择“Devices”选项卡，然后选择“Add Device”
在 Device Type 字段中键入“Wear”，并在 Device ID 字段中键入“myWatch”，然后单击“Continue”

保存设备凭证（Organization ID、Device type and ID 和 Authentication Token）

在您的移动模块中导入 mqtt 库

在 HeartRatemobilelibs org.eclipse.paho.android.service.jar 和 org.eclipse.paho.client.mqttv3.jar 文件中填写相应的内容
关闭并重新打开项目

更新移动清单

添加 mqtt 服务：

<service android:name="org.eclipse.paho.android.service.MqttService" />

添加 WAKE_LOCK 权限：

<uses-permission android:name="android.permission.WAKE_LOCK" />

创建 MQTTHandler

创建新的 MqttHandler 类，复制以下代码并更改组织和设备令牌：

public class MqttHandler implements MqttCallback {    private static MqttHandler instance;  private MqttAndroidClient mqttClient;  Context context;    private static String ORG = "YOUR_IOT_ORGANISATION";  private static String DEVICE_TYPE = "Wear";  private static String DEVICE_ID = "myWatch";  private static String TOKEN = "YOUR_DEVICE_TOKEN";  private static String TOPIC = "iot-2/evt/hr/fmt/json";    private MqttHandler(Context context) {  this.context = context;  }      public static MqttHandler getInstance(Context context) {  if (instance == null) {  instance = new MqttHandler(context);  }  return instance;  }      @Override  public void connectionLost(Throwable throwable) {  }    @Override  public void messageArrived(String topic, MqttMessage mqttMessage) throws Exception {  }    @Override  public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {  }    public void connect(IMqttActionListener listener) {  if (!isConnected()) {  String iotPort = "1883";  String iotHost = ORG+".messaging.internetofthings.ibmcloud.com";  String iotClientId = "d:"+ORG+":"+DEVICE_TYPE+":"+DEVICE_ID;    String connectionUri = "tcp://" + iotHost + ":" + iotPort;    if (mqttClient != null) {  mqttClient.unregisterResources();  mqttClient = null;  }    mqttClient = new MqttAndroidClient(context, connectionUri, iotClientId);  mqttClient.setCallback(this);    MqttConnectOptions options = new MqttConnectOptions();  options.setCleanSession(true);  options.setUserName("use-token-auth");  options.setPassword(TOKEN.toCharArray());    try {  mqttClient.connect(options, context, listener);  } catch (MqttException e) {    }  }  }    public void disconnect(IMqttActionListener listener) {  if (isConnected()) {  try {  mqttClient.disconnect(context, listener);  mqttClient = null;  } catch (MqttException e) {  e.printStackTrace();  }  }  }    public void publish(long timestamp, float heartRateValue) {  if (isConnected()) {  String msg = "{'timestamp':"+timestamp+",'heartRate':"+heartRateValue+"}";  MqttMessage mqttMsg = new MqttMessage(msg.getBytes());  mqttMsg.setRetained(false);  mqttMsg.setQos(0);  try {  mqttClient.publish(TOPIC, mqttMsg);  } catch (Exception e) {    }  }  }    private boolean isConnected() {  if (mqttClient != null) {  return mqttClient.isConnected();  }  return false;  }  }

连接到 IoT foundation

打开 HeartRateMobileActivity，添加此属性：

private boolean connected = false;

在 onStart 函数的末尾处添加此代码：

MqttHandler.getInstance(this).connect(new IMqttActionListener() {  @Override  public void onSuccess(IMqttToken iMqttToken) {  connected = true;  }   @Override  public void onFailure(IMqttToken iMqttToken, Throwable throwable) {  } });

在 onStop 函数的开头处添加此代码：

MqttHandler.getInstance(this).disconnect(new IMqttActionListener() {  @Override  public void onSuccess(IMqttToken iMqttToken) {  connected = false;  }   @Override  public void onFailure(IMqttToken iMqttToken, Throwable throwable) {  } });

向 IoT Fundation 发送心率

使用下列代码更新 onReceive 函数：

点击查看代码清单

关闭 [x]

public void onReceive(Context arg0, Intent arg1) {  // ahr  Log.v(this.getClass().getName(), "Value Recieved");  if (arg1.getAction().equals("heartRateAction")) {  float hr = arg1.getFloatExtra("HeartRate", 0);  long ts = arg1.getLongExtra("timestamp", 0);  ((TextView)HeartRateMobileActivity.this.findViewById(R.id.heartRateTextView)).setText("Heart Rate : " + hr);   if (connected)  MqttHandler.getInstance(HeartRateMobileActivity.this).publish(ts, hr);   } }

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