I'm having a huge problem for days. In fact, in my activity, I call an NTP server which I do using an async-task and I do multiple database operations(I'm using Firebase Database), and whenever this activity opens, there's an ANR error. I read that for long tasks, we should use a worker thread so I put the database operations in a thread but even with that, I still get an ANR error. What else do you suggest ? (the NTP server returns the correct result and all the operations in database are done everytime, even though I get the ANR error.)
public class Start extends AppCompatActivity {
//declaring variables
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start);
new Thread(new Runnable() {
public void run(){
finishQuiz();
}
}).start();
final DatabaseReference myRef = FirebaseDatabase.getInstance().getReference();
myRef.addValueEventListener(new ValueEventListener() {
//in this part, I call getNetworkTime, and under specific conditions I set an intent AlarmManager
}
Here is the function finishQuiz() I call inside the thread :
public void finishQuiz() {
// DEFINING THE VARIABLES NEEDED
myRef.addListenerForSingleValueEvent( new ValueEventListener() {
String dateD, hourD, userID, nom, prenom;
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
Date d = new Date();
timee = d.getTime();
try {
timee = new Start.getNetworkTime().execute().get();
} catch (Exception e) {
timee = d.getTime();
}
String dateD = dataSnapshot.child("quiz").child("dateD").getValue(String.class);
String hourD = dataSnapshot.child("quiz").child("heureD").getValue(String.class);
if (!(dateD.equals("")) && !(hourD.equals(""))) {
long nbQ = dataSnapshot.child("quiz").child("questions").getChildrenCount();
int dureeQ = Integer.valueOf(dataSnapshot.child("quiz").child("duree").getValue().toString());
String[] D = dateD.split("-", 3);
String[] H = hourD.split(":", 3);
Calendar calDebut = Calendar.getInstance();
calDebut.set(Integer.valueOf(D[2]), Integer.valueOf(D[1]) - 1, Integer.valueOf(D[0]), Integer.valueOf(H[0]), Integer.valueOf(H[1]), Integer.valueOf(H[2]));
Date dateDebutQ = calDebut.getTime();
long timeQFinInMillis = dateDebutQ.getTime() + (nbQ + 1) * dureeQ * 1000;
if (timee > timeQFinInMillis) {
try {
final SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH:mm");
Calendar caldateQ = Calendar.getInstance();
String[] dateDT = dateD.split("-", 3);
String[] hourDT = hourD.split(":", 3);
caldateQ.set(Integer.valueOf(dateDT[2]), Integer.valueOf(dateDT[1]) - 1, Integer.valueOf(dateDT[0]), Integer.valueOf(hourDT[0]), Integer.valueOf(hourDT[1]), Integer.valueOf(hourDT[2]));
long c = caldateQ.getTimeInMillis();
List<Date> listPast = new ArrayList<>();
List<Date> listFuture = new ArrayList<>();
for (DataSnapshot ds : dataSnapshot.child("next quizs").getChildren()) {
String dateNext = ds.getKey();
try {
Date dateNx = formatter.parse(dateNext);
Date dateQQQ = caldateQ.getTime();
Date dateQQ = formatter.parse(formatter.format(dateQQQ));
long timeNx = dateNx.getTime();
if (timeNx < timee) {
listPast.add(dateNx);
}
else
{
listFuture.add(dateNx);
}
} catch (Exception e) {
}
}
for (int i = 0; i < listPast.size(); i++) {
myNextQuiz.child(formatter.format(listPast.get(i))).removeValue();
}
if (listFuture.size()==0) {
myQuiz.child("dateD").setValue("");
myQuiz.child("heureD").setValue("");
myQuiz.child("duree").setValue(10);
myQuiz.child("questions").setValue("This will be removed anyways");
} else
//I get ANR error in this case
{
Date minuD = listFuture.get(0);
for (int k = 1; k < listFuture.size(); k++) {
if ((listFuture.get(k).compareTo(minuD) < 0)) {
minuD = listFuture.get(k);
}
}
String date = formatter.format(minuD);
String[] DH = date.split(" ", 2);
myQuiz.child("dateD").setValue(DH[0]);
myQuiz.child("heureD").setValue(DH[1] + ":00");
String ddd = dataSnapshot.child("next quizs").child(date).child("duree").getValue().toString();
myQuiz.child("duree").setValue(ddd);
myQuiz.child("questions").removeValue();
int j = 1;
for (DataSnapshot ds : dataSnapshot.child("next quizs").child(date).child("questions").getChildren()) {
String quest = ds.child("question").getValue(String.class);
String sol = ds.child("sol").getValue(String.class);
String answA = ds.child("A").getValue(String.class);
String answB = ds.child("B").getValue(String.class);
String answC = ds.child("C").getValue(String.class);
String answD = ds.child("D").getValue(String.class);
myQuiz.child("questions").child("" + j).child("question").setValue(quest);
myQuiz.child("questions").child("" + j).child("sol").setValue(sol);
myQuiz.child("questions").child("" + j).child("A").setValue(answA);
myQuiz.child("questions").child("" + j).child("B").setValue(answB);
myQuiz.child("questions").child("" + j).child("C").setValue(answC);
myQuiz.child("questions").child("" + j).child("D").setValue(answD);
j++;
}
}
myPreQuiz.child(dateD + " " + hourD).child("dateD").setValue(dateD);
myPreQuiz.child(dateD + " " + hourD).child("heureD").setValue(hourD);
for (DataSnapshot ds : dataSnapshot.child("current quiz").child("number").getChildren()) {
userID = ds.getKey();
nom = dataSnapshot.child("utilisateurs").child(userID).child("Nom").getValue(String.class);
prenom = dataSnapshot.child("utilisateurs").child(userID).child("Prenom").getValue(String.class);
myPreQuiz.child(dateD + " " + hourD).child("gagnants").child(userID).setValue(nom + " " + prenom);
}
myCurrQuiz.child("currentQ").setValue("0");
myCurrQuiz.child("number").removeValue();
} catch (Exception e) {
//show Exception
} }}}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});}
And here's my async Task :
private class getNetworkTime extends AsyncTask<Void, Void, Long> {
@Override
protected Long doInBackground(Void... params) {
String TIME_SERVER = "2.android.pool.ntp.org";
try{
NTPUDPClient timeClient = new NTPUDPClient();
InetAddress inetAddress = InetAddress.getByName(TIME_SERVER);
TimeInfo timeInfo = timeClient.getTime(inetAddress);
long returnTime = timeInfo.getMessage().getTransmitTimeStamp().getTime(); //server time
return returnTime;
} catch (Exception e) {
Date d = new Date();
long l=d.getTime();
return l;
}
}
protected void onPostExecute(Long result) {
}
@Override
protected void onPreExecute() {
}
@Override
protected void onProgressUpdate(Void... values) {
}
}
If it is helpful, before I use the NTP server, my code used to work perfectly, and I tested without the AlarmManager part and it worked fine too, and also, in the function finishQuiz(), as I mentioned in a comment, only that particular case gives the ANR error(which happens to be the most common case for my app), I mean without entering that block, there's no ANR error.
