我是Android新手，我正在尝试使用Estimote Beacons构建一个Android应用程序。我想从Web服务获取动态通知。为此，我在Android应用程序类中添加了网络调用，以便它可以在后台连续调用。我面临的问题有时是网络呼叫触发，有时则不会。从Application类进行网络调用是否是礼仪性的事情。我该怎么做呢？下面我附上了Application类代码。
public class AppController extends Application {
public static final String TAG = AppController.class.getSimpleName();
private boolean beaconNotificationsEnabled = false;
SharedPreferences sharedPreferences;
Editor editor;
private RequestQueue mRequestQueue;
String uuid_beacon;
String displayNotification;
private BeaconManager beaconManager;
private static AppController mInstance;
String authLoginValue;
String displayMinorNO;
String uuid;
String majorno;
String minorno;
String notify;
String urlforimage;
@Override
public void onCreate() {
super.onCreate();
sharedPreferences = getApplicationContext().getSharedPreferences("Reg", 0);
editor = sharedPreferences.edit();
mInstance = this;
authLoginValue = sharedPreferences.getString("AuthTokenLogin", "");
System.out.println("LOGIN FROM APP CONTROLLER:"+authLoginValue);
beaconManager = new BeaconManager(getApplicationContext());
beaconManager.setMonitoringListener(new BeaconManager.MonitoringListener() {
@Override
public void onEnteredRegion(Region region, List<Beacon> list) {
System.out.println("ENETERD");
for (Beacon beacon : list) {
uuid = beacon.getProximityUUID().toString();
majorno = String.valueOf(beacon.getMajor());
minorno = String.valueOf(beacon.getMinor());
sendUUID(uuid, authLoginValue, majorno, minorno);
}
displayNotification = sharedPreferences.getString("Notification", "");
showNotification(displayNotification, "Click here to continue");
}
@Override
public void onExitedRegion(Region region) {
// could add an "exit" notification too if you want (-:
showNotification(
"THANKS FOR VISITING",
"Come back again"
);
}
});
beaconManager.connect(new BeaconManager.ServiceReadyCallback() {
@Override
public void onServiceReady() {
beaconManager.startMonitoring(new Region("monitored region",
UUID.fromString("B9407F30-F5F8-466E-AFF9-25556B57FE6D"), null, null));
}
});
}
public static synchronized AppController getInstance() {
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
public <T> void addToRequestQueue(Request<T> req, String tag) {
req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
getRequestQueue().add(req);
}
public <T> void addToRequestQueue(Request<T> req) {
req.setTag(TAG);
getRequestQueue().add(req);
}
public void cancelPendingRequests(Object tag) {
if (mRequestQueue != null) {
mRequestQueue.cancelAll(tag);
}
}
public void showNotification(String title, String message) {
Intent notifyIntent = new Intent(this, MainActivity.class);
notifyIntent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent pendingIntent = PendingIntent.getActivities(this, 0,
new Intent[]{notifyIntent}, PendingIntent.FLAG_UPDATE_CURRENT);
Notification notification = new Notification.Builder(this)
.setSmallIcon(R.drawable.logo_7edge)
.setContentTitle(title)
.setContentText(message)
.setAutoCancel(true)
.setContentIntent(pendingIntent)
.build();
notification.defaults |= Notification.DEFAULT_SOUND;
NotificationManager notificationManager =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(1, notification);
}
public void sendUUID(final String uuid, final String authTokenLoginValue,final String majorno, final String minorno) {
// Tag used to cancel the request
String tag_string_req = "req_register";
StringRequest strReq = new StringRequest(Request.Method.POST,
AppConfig.URL_UUID, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.d(TAG, "Notification Response: " + response.toString());
try {
JSONObject jObj = new JSONObject(response);
String notifyresponse = jObj.getString("notification");
JSONObject objecttonotify = new JSONObject(notifyresponse);
notify = objecttonotify.getString("notification");
urlforimage = objecttonotify.getString("url");
System.out.println("URL:"+urlforimage);
editor.putString("Notification", notify);
editor.putString("image_url", urlforimage);
editor.commit();
Log.d(TAG, "Notification1" + notify);
String msg =jObj.get("status").toString();
if(msg.equals("ok"))
{
String SuccessMsg = jObj.getString("message");
//Toast.makeText(getApplicationContext(), SuccessMsg, Toast.LENGTH_LONG).show();
}
else if(msg.equals("error")) {
String errorMsg = jObj.getString("message");
Toast.makeText(getApplicationContext(), errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Notification Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("uuid", uuid);
params.put("authtoken", authTokenLoginValue);
params.put("major_no", majorno);
params.put("minor_no", minorno);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
答案 0 :(得分：0)
如果您的代码在您指示的情况下间歇性地进行了网络呼叫，那么在我看来，根据您的Web /服务器参数，代码正在运行。因此我假设连接[通过Volley]的尝试是合理的。
但是，您没有注明[根据您发布的代码判断]您已检查设备是否启用了BT，启用了网络和Internet可用性。为了判断您的代码是否始终如一地工作，以确保首先确保移动设备已启用BT，启用网络并可访问Internet。以下代码段对我有用......当然包括所有必要的用户权限：
启用蓝牙：
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (!mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.enable();
网络和互联网：
public static NetworkInfo getNetworkInfo(Context context){
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
return cm.getActiveNetworkInfo();
}
//Check if there is any connectivity
public static boolean isConnected(Context context){
NetworkInfo info = Utilities.getNetworkInfo(context);
return (info != null && info.isConnected());
}
// Check if there is any connectivity to a Wifi network
public static boolean isConnectedWifi(Context context){
NetworkInfo info = Utilities.getNetworkInfo(context);
return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI);
}
// Check if there is any connectivity to a mobile network
public static boolean isConnectedMobile(Context context){
NetworkInfo info = Utilities.getNetworkInfo(context);
return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_MOBILE);
}
// TEST FOR INTERNET ACCESS / WEBSITE AVAILABLE
public static boolean isInternetOn() {
String command = "ping -c1 -w3 google.com";
// TODO progress bar while checking for internet.
try {
return (Runtime.getRuntime().exec(command).waitFor() == 0);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return false;
} //EO Internet ping
希望它有所帮助。