在Android Wear中使用现有数据库

我找到了一个快速的解决方案，可以将整个数据库从手机传输到Smartwatch。

首先，我创建一个帮助程序类，该类将数据库内容转换为json-string，可以使用Wearable.DataApi将其发送到smartwatch ：

DatabaseToJSON.java：

public class DatabaseToJSON {
DatabaseHandler dbhandler;

public DatabaseToJSON(Context context) {
    dbhandler = new DatabaseHandler(context);
}

public JSONObject getJSON() throws JSONException{
    Item[] item = null;
    JSONObject pl = new JSONObject();
    item = dbhandler.getItems();
    dbhandler.close();
    JSONArray jsonArray = new JSONArray();  
    for(int i=0;i<item.length;i++){
        JSONObject val = new JSONObject();
        try {
            val.put("id", item[i].getID());
            val.put("name", item[i].getName());
            ...
            jsonArray.put(val);
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        pl.put(String.valueOf(j), jsonArray);
    }

     if(jsonArray.length()<1){
       pl.put(String.valueOf(j),new JSONArray());
     }

    }

    JSONObject result = new JSONObject();
    result.put("data",pl);
    return result;      
} }

DemoActivity.java（电话）：

public class DemoActivity extends Activity implements  GoogleApiClient.ConnectionCallbacks,  GoogleApiClient.OnConnectionFailedListener {

/** Android Wear **/
GoogleApiClient googleClient;

@Override
public void onStart(){
    super.onStart();
    googleClient.connect();
}


@Override
public void onStop(){
    if (null != googleClient && googleClient.isConnected()) {
        googleClient.disconnect();
    }
    super.onStop();
}

 @Override
 protected void onCreate(Bundle savedInstanceState) {  
     super.onCreate(savedInstanceState);  
     googleClient = new GoogleApiClient.Builder(this)
             .addApi(Wearable.API)
             .addConnectionCallbacks(this)
             .addOnConnectionFailedListener(this)
             .build();

     ...
}

@Override
public void onConnected(Bundle bundle) {

    DatabaseToJSON dbJson = new DatabaseToJSON(DemoActivity.this);
    try {
        JSONObject json = dbJson.getJSON();
        new SendToDataLayerThread("/path", json.toString()).start();
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

class SendToDataLayerThread extends Thread {
    String path;
    String message;

    SendToDataLayerThread(String p, String msg) {
        path = p;
        message = msg;
    }

    public void run() {
        NodeApi.GetConnectedNodesResult nodes = Wearable.NodeApi.getConnectedNodes(googleClient).await();
        for (Node node : nodes.getNodes()) {
            MessageApi.SendMessageResult result = Wearable.MessageApi.sendMessage(googleClient, node.getId(), path, message.getBytes()).await();
            if (result.getStatus().isSuccess()) {
                Log.v("myTag", "Message: {" + message + "} sent to: " + node.getDisplayName());
            }
            else {
                Log.v("myTag", "ERROR: failed to send Message");
            }
        }
    }
}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {

}

}

DataLayerListenerService.java（wear）

public class DataLayerListenerService extends WearableListenerService {

@Override
public void onMessageReceived(MessageEvent messageEvent) {

if (messageEvent.getPath().equals("/path")) {
    final String message = new String(messageEvent.getData());


    // do what you want with the json-string
    SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    SharedPreferences.Editor edit = pref.edit();
    edit.putString("demo_json",message).apply();

}
else {
    super.onMessageReceived(messageEvent);
}
}

添加到AndroidManifest.xml（wear）

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

收到穿戴上的json-string后，您可以将它们保存在穿戴上的数据库中，或对其进行其他操作...

我认为这是在手持设备和穿戴设备之间传输此类数据的最简单方法。