Develop Reference

Why my android app is giving "your app keeps stopping" while connecting to mqtt broker

I have written a code to connect my android app to mqtt server in android studio. I have added button "connect" after clicking it will show me connect message on screen. The moment I click the connect button, I get the message your android app keeps stopping. here is my code. I have uploaded necessary repositories and dependency and also permissions
public class MainActivity extends AppCompatActivity {
MqttAndroidClient client;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String clientId = MqttClient.generateClientId();
client =
new MqttAndroidClient(this.getApplicationContext(), "tcp://mqtt.eclipse.org:1883",
clientId);
}
public void test(View V){
try {
IMqttToken token = client.connect();
token.setActionCallback(new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
// We are connected
Toast.makeText(MainActivity.this,"connected",Toast.LENGTH_LONG).show();
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Toast.makeText(MainActivity.this,"disconnected",Toast.LENGTH_LONG).show();
}
});
} catch (MqttException e) {
e.printStackTrace();
}
}
}

Error Solved. There was problem in local broadcast manager file.

How to change Wifi P2P device name?

I am trying to detect and connect two Android mobiles using Wifi P2P method and I have been successful in it. But, I want a different name to be shown on the other device when it discovers mine.
Since, I am using Samsung J7 Prime 2(Android 9), changing Device name or Bluetooth name changes the Wifi P2p name, but the code for that didn't work. I tried the same code on Android 6.0.1 i.e. API 23 and it worked fine.
swtWifi.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
changeDevName("Tony Stark");
}
});
public void changeDevName(String devNewName) {
try {
Method method = manager.getClass().getMethod("setDeviceName", WifiP2pManager.Channel.class, String.class, WifiP2pManager.ActionListener.class);
method.invoke(manager, channel, devNewName, new WifiP2pManager.ActionListener() {
#Override
public void onSuccess() {
Toast.makeText(MainActivity.this, "Name successfully changed", Toast.LENGTH_LONG).show();
}
#Override
public void onFailure(int reason) {
Toast.makeText(MainActivity.this, "Request failed: " + reason, Toast.LENGTH_SHORT).show();
}
});
} catch (Exception e) {
e.printStackTrace();
}
}

Tunring my android to beacon and detecting

Is this right way of doing? AM using this samples https://altbeacon.github.io/android-beacon-library/samples.html
public class App extends Application
implements BootstrapNotifier, BeaconConsumer, RangeNotifier {
private final String TAG = "Application ";
protected static final Region beaconRegion = new Region("2f234454-cf6d-4a0f-adf2-f4911ba9ffa6", null, null, null);
protected BeaconManager beaconManager = null;
private RegionBootstrap regionBootstrap;
private BackgroundPowerSaver backgroundPowerSaver;
protected static String sLog = "";
#Override
public void onCreate() {
super.onCreate();
logIt(TAG, beaconRegion.getId1()+"onCreate - In"+beaconRegion.getUniqueId());
beaconManager = org.altbeacon.beacon.BeaconManager.getInstanceForApplication(this);
beaconManager.getBeaconParsers().clear();
beaconManager.getBeaconParsers().add(new BeaconParser().
setBeaconLayout("m:2-3=0215,i:4-19,i:20-21,i:22-23,p:24-24"));//iBeacon (tutti)
//--- wake up the app when a beacon is seen
regionBootstrap = new RegionBootstrap(this, beaconRegion);
//--- activate power saver
backgroundPowerSaver = new BackgroundPowerSaver(this);
beaconManager.bind(this);
logIt(TAG, "onCreate - Out");
}
private void logIt (String TAG, String msg) {
sLog += TAG + msg + "\n";
Log.w(TAG, msg);
}
//-------------------------//
//--- BootstrapNotifier ---//
//-------------------------//
#Override
public void didDetermineStateForRegion(int state, Region region) {
String msg = "didDetermineStateForRegion ";
switch(state) {
case MonitorNotifier.INSIDE:
msg +="(INSIDE)";
break;
case MonitorNotifier.OUTSIDE:
msg +="(OUTSIDE)";
break;
default:
msg +="(state=" +state +")";
break;
}
logIt(TAG, msg);
}
#Override
public void didEnterRegion(Region arg0) {
logIt(TAG, "didEnterRegion - In");
try {
beaconManager.startRangingBeaconsInRegion(beaconRegion);
logIt(TAG,"dER - startRangingBeaconsInRegion OK");
} catch (RemoteException e) {
logIt(TAG, "dER - startRangingBeaconsInRegion Err " +e);
}
logIt(TAG, "didEnterRegion - Out");
}
#Override
public void didExitRegion(Region region) {
logIt(TAG, "didExitRegion - In");
try {
beaconManager.stopRangingBeaconsInRegion(beaconRegion);
logIt(TAG,"dXR - stopRangingBeaconsInRegion OK");
} catch (RemoteException e) {
logIt(TAG, "dXR - stopRangingBeaconsInRegion Err " +e);
}
logIt(TAG, "didExitRegion - Out");
}
//----------------------//
//--- BeaconConsumer ---//
//----------------------//
#Override
public void onBeaconServiceConnect() {
logIt(TAG, "onBeaconServiceConnect - In");
beaconManager.setRangeNotifier(this);
logIt(TAG, "onBeaconServiceConnect - Out");
}
//---------------------//
//--- RangeNotifier ---//
//---------------------//
#Override
public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region region) {
logIt(TAG, "didRangeBeaconsInRegion - " +beacons.size() +" beacons");
Toast.makeText(getApplicationContext(), beaconRegion.getId1()+" beacon detected "+beacons.size(),
Toast.LENGTH_SHORT).show();
for(Beacon beac: beacons)
{
System.out.println(beac.getId1()+"id 1"+TAG);
if(beac.getId1().equals("2f234454-cf6d-4a0f-adf2-f4911ba9ffa6")/send notification
}
}
}
So Basically that class, which extends application am listening to beacons around. Below, is how am turning my phone into a beacon.I am doing this inside an activity on click of button. So there is two phones with app downloaded on both, once he clicks on one app the button I want the other phone to detect it since i have implemented in extends application class.
the turn ur android to beacon code.
Beacon beacon = new Beacon.Builder()
.setId1("2f234454-cf6d-4a0f-adf2-f4911ba9ffa6") // UUID for beacon
.setId2("1") // Major for beacon
.setId3("5") // Minor for beacon
.setManufacturer(0x004C) // Radius Networks.0x0118 Change this for other beacon layouts//0x004C for iPhone
.setTxPower(-56) // Power in dB
.setDataFields(Arrays.asList(new Long[]{0l})) // Remove this for beacon layouts without d: fields
.build();
BeaconParser beaconParser = new BeaconParser()
.setBeaconLayout("m:2-3=0215,i:4-19,i:20-21,i:22-23,p:24-24");
beaconTransmitter = new BeaconTransmitter(MenuActivity.this, beaconParser);
beaconTransmitter.startAdvertising(beacon, new AdvertiseCallback() {
#Override
public void onStartFailure(int errorCode) {
Log.e("tag", "Advertisement start failed with code: " + errorCode);
}
#Override
public void onStartSuccess(AdvertiseSettings settingsInEffect) {
Log.i("tag", "Advertisement start succeeded.");
Toast.makeText(MenuActivity.this, "advertisement start succeeded",
Toast.LENGTH_SHORT).show();
System.out.println("startedddddddddddd");
}
});
// beaconTransmitter.stopAdvertising();
}
catch(Exception o)
{
System.out.println("affda "+o.getMessage());
}
I am also havig an issue, that didenterregion and didRangeBeaconsInRegion are fired many times, so am sending many notification to the user multiple times. its not user friendly.

The didRangeBeaconsInRegion callback is supposed to get called many times -- that's how ranging works. It is called approximately once per second when the beacon is detected to tell you it is there and give you a distance estimate.
If you want to fire a notification only once for the first time you get a call to this method, then you can set a flag for this specific beacon.
Here is an example of some code you might use to do that:
// Add this to the top of your class
private HashMap<String,Boolean> mAlreadySentNotification = new HashMap<String,Boolean>();
...
// Add this to the inside of your didRangeBeaconsInRegion method
if (mAlreadySentNotification.get(beacon.toString())) {
mAlreadySentNotification.put(beacon.toString(), true);
// Send notification here.
}

Android: Broadcast Receiver does not receive BluetoothDevice.ACTION_ACL_CONNECTED on restarting the application

I want my app to auto-connect to already connected bluetooth device on restarting the app. Below is procedure I am performing:-
[Initially] Bluetooth device is 'ON': Then on starting the app.
[Behavior]--> Bluetooth device gets paired and connected successfully ( Intent 'ACTION_ACL_CONNECTED' is received)
Bluetooth device is 'ON': Closed the app, then started the app again.
[Behavior]--> Even though it is connected as displayed on Bluetooth setting, and Broadcast Receiver does not receive Intent 'ACTION_ACL_CONNECTED'.
Note:- On closing the app, it does not disconnect the bluetooth connection.
So, on successful connection app straightaway goes to the HomeScreen. Otherwise, the app goes to a screen having button that takes it to Bluetooth setting(onClickListener present in the code below)
I am new to android development, so I really don't know where am I going wrong. I looked up the solutions for similar issues and applied them, but to no effect.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_index);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED);
registerReceiver(mReceiver, filter);
IntentFilter filter1 = new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED);
this.registerReceiver(mReceiver, filter1);
m_app = (BtApp) getApplication();
imagebt = (ImageView) this.findViewById(R.id.imagebt);
imagebt.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
final Toast tag = Toast.makeText(getApplicationContext(), "Connect to device", Toast.LENGTH_LONG);
tag.show();
new CountDownTimer(1000, 1000)
{
public void onTick(long millisUntilFinished) {tag.show();}
public void onFinish() {
//tag.show();
}
}.start();
if(mBluetoothAdapter != null && mBluetoothAdapter.isEnabled()){
mBluetoothAdapter.startDiscovery();
}
Intent intentBluetooth = new Intent();
intentBluetooth.setAction(android.provider.Settings.ACTION_BLUETOOTH_SETTINGS);
startActivity(intentBluetooth);
}
});
}
private BroadcastReceiver mReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if ( BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
m_app.m_main.setupCommPort();
device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
m_app.m_device = device;
isconnected = true;
new Timer().schedule(new TimerTask() {
#Override
public void run() {
if ( m_app.m_main.m_BtService != null && m_app.m_main.m_BtService.getState() != BluetoothRFCommService.STATE_CONNECTED ) {
m_app.m_main.m_BtService.connect(device, false);
}
}
}, 3500);
} else if ( BluetoothDevice.ACTION_ACL_DISCONNECTED.equals(action) ) {
isconnected = false;
m_app.m_main.tabHost.setCurrentTab(0);
}
}
};
#Override
protected void onStop()
{
unregisterReceiver(mReceiver);
super.onStop();
}

You won't get BluetoothDevice.ACTION_ACL_CONNECTED event since the device is still connected. The event is fired only on changing of device state from disconnected to connected.
You have 2 options.
You can put your BroadcastReceiver with BluetoothDevice.ACTION_ACL_CONNECTED and BluetoothDevice.ACTION_ACL_DISCONNECTED filters into the Service and track the device connection state in the background. On your app startup you can ask the service to give you the current state of the device.
You can check if some of the Bluetooth profiles contains your device name in the list of connected devices.
For API 18+ you can use BluetoothManager#getConnectedDevices() for API below 18 you can use the following snippet (for each Bluetooth profile)
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
BluetoothProfile.ServiceListener mProfileListener = new BluetoothProfile.ServiceListener() {
public void onServiceConnected(int profile, BluetoothProfile proxy) {
for (BluetoothDevice device : proxy.getConnectedDevices()) {
if (device.getName().contains("DEVICE_NAME")) {
deviceConnected = true;
}
}
if (!deviceConnected) {
Toast.makeText(getActivity(), "DEVICE NOT CONNECTED", Toast.LENGTH_SHORT).show();
}
mBluetoothAdapter.closeProfileProxy(profile, proxy);
}
public void onServiceDisconnected(int profile) {
// TODO
}
};
mBluetoothAdapter.getProfileProxy(context, mProfileListener, BluetoothProfile.A2DP);

Libgdx and Google In-App-Purchase result

I followed these instructions to integrate both Libgdx and native android code using ActionResolver interface. I have no problem calling the Android method from the Libgdx part of my code. But I am hitting a dead end when I am trying to intergrate Google IAP with Libgdx. According to TrivialDrive example, it uses mPurchaseFinishedListener (outside of calling method).
My question is: how do I pass this IAP resultcode back to Libgdx since the listener is outside the calling method? Currently, purchase process went through, but the libgdx part of my code is not being "informed" of the purchase status/result.
This is my code:
Any help is much appreciated.
ActionResolver:
public interface IActionResolver {
public int requestIabPurchase(int product);
}
MainActivity:
public class MainActivity extends AndroidApplication implements IActionResolver {
// Debug tag, for logging
static final String TAG = "greatgame";
// Does the user have the premium upgrade?
boolean mIsUpgraded = false;
// SKUs for our products: the cat, all, or pow
static final String SKU_UPGRADE = "android.test.purchased";
// (arbitrary) request code for the purchase flow
static final int RC_REQUEST = 10001;
// The helper object
IabHelper mHelper;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
AndroidApplicationConfiguration cfg = new AndroidApplicationConfiguration();
cfg.useGL20 = false;
initialize(new Catland(this), cfg);
}
void iAbStartup() {
String base64EncodedPublicKey = "some key";
// Create the helper, passing it our context and the public key to verify signatures with
Log.d(TAG, "Creating IAB helper.");
mHelper = new IabHelper(this, base64EncodedPublicKey);
// enable debug logging (for a production application, you should set this to false).
mHelper.enableDebugLogging(true);
// Start setup. This is asynchronous and the specified listener
// will be called once setup completes.
Log.d(TAG, "Starting setup.");
mHelper.startSetup(new IabHelper.OnIabSetupFinishedListener() {
public void onIabSetupFinished(IabResult result) {
Log.d(TAG, "Setup finished.");
if (!result.isSuccess()) {
// Oh noes, there was a problem.
Log.d(TAG, "Problem setting up in-app billing: " + result);
return;
}
// Have we been disposed of in the meantime? If so, quit.
if (mHelper == null) {
return;
}
// IAB is fully set up. Now, let's get an inventory of stuff we own.
Log.d(TAG, "Setup successful. Querying inventory.");
mHelper.queryInventoryAsync(mGotInventoryListener);
}
});
}
// Listener that's called when we finish querying the items and subscriptions we own
IabHelper.QueryInventoryFinishedListener mGotInventoryListener = new IabHelper.QueryInventoryFinishedListener() {
public void onQueryInventoryFinished(IabResult result, Inventory inventory) {
Log.d(TAG, "Query inventory finished.");
// Have we been disposed of in the meantime? If so, quit.
if (mHelper == null) {
return;
}
// Is it a failure?
if (result.isFailure()) {
Log.d(TAG, "Failed to query inventory: " + result);
return;
}
Log.d(TAG, "Query inventory was successful.");
// Do we have the SKU_UPGRADE upgrade?
Purchase thisUpgrade = inventory.getPurchase(SKU_UPGRADE);
mIsUpgraded = (thisUpgrade != null && verifyDeveloperPayload(thisUpgrade));
Log.d(TAG, "User is " + (mIsUpgraded ? "Upgraded" : "Free"));
Log.d(TAG, "Initial inventory query finished; enabling main UI.");
runPurchaseFlow(submitProduct);
}
};
// Run real purchase flow
public void runPurchaseFlow(int product) {
Log.d(TAG, "runPurchaseFlow");
/* TODO: for security, generate your payload here for verification. See the comments on
* verifyDeveloperPayload() for more info. Since this is a SAMPLE, we just use
* an empty string, but on a production app you should carefully generate this. */
String payload = "";
if (product == 1)
mHelper.launchPurchaseFlow(this, SKU_UPGRADE, RC_REQUEST, mPurchaseFinishedListener, payload);
}
// Callback for when a purchase is finished
IabHelper.OnIabPurchaseFinishedListener mPurchaseFinishedListener = new IabHelper.OnIabPurchaseFinishedListener() {
public void onIabPurchaseFinished(IabResult result, Purchase purchase) {
Log.d(TAG, "Purchase finished: " + result + ", purchase: " + purchase);
// if we were disposed of in the meantime, quit.
if (mHelper == null) return;
if (result.isFailure()) {
Log.d(TAG, "Error purchasing: " + result);
return;
}
if (!verifyDeveloperPayload(purchase)) {
Log.d(TAG, "Error purchasing. Authenticity verification failed.");
return;
}
Log.d(TAG, "Purchase successful.");
if (purchase.getSku().equals(SKU_CAT)) {
// bought the upgrade!
Log.d(TAG, "Purchase Upgrade. Congratulating user.");
mIsUpgraded = true;
// how do i pass this result to the libgdx?
}
}
};
/** Verifies the developer payload of a purchase. */
boolean verifyDeveloperPayload(Purchase p) {
String payload = p.getDeveloperPayload();
return true;
}
#Override
public int requestIabPurchase(int product) {
iAbStartup();
return 0; // how do i get the result from mPurchaseFinishedListener?
}
}
PurchaseScreen
result = greatgame.actionResolver.requestIabPurchase(1);

You won't be able to return the result from requestIabPurchase() - the only methods of doing so would block for a long time. The best way, in my opinion, would be to create a listener interface of your own that your LibGdx project implements, and pass that into your request interface. For example:
In your libGdx project somewhere:
interface PurchaseCallback {
public int setPurchaseResult(int result);
}
ActionResolver:
public interface IActionResolver {
public int requestIabPurchase(int product, PurchaseCallback callback);
}
In PurchaseScreen, implement PurchaseCallback:
#override
public int setPurchaseResult(int result) {
// Yay! I have a result from a purchase! Maybe you want a boolean instead of an int? I don't know. Maybe an int (for the product code) and a boolean.
}
...and pass whatever is implementing PurchaseCallback (I'm assuming your PurchaseScreen does itself):
result = greatgame.actionResolver.requestIabPurchase(1, this);
Finally, hook it all up in MainActivity:
PurchaseCallback mCallback = null;
mPurchaseFinishedListener = ... etc. etc.
.
.
.
if (mCallback != null) {
mCallback.setPurchaseResult(0);
}
.
.
.
#Override
public int requestIabPurchase(int product, PurchaseCallback callback) {
mCallback = callback; // save this for later
iAbStartup();
return 0;
}
Note that you should call PurchaseCallback.setPurchaseResult() everywhere that mPurchaseFinishedListener has return, not only at the line // how do i pass this result to the libgdx? - otherwise, you will never know if a purchase failed or is just taking a really long time.