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Firebase dataSnapshot.getValue(Subclass.class) function never returns
How to store and view images on firebase?Query based on multiple where clauses in FirebaseFirebase: datasnapshot.getValue(className) not workingGet children using orderByChild-equalsTo in Firebase-AndroidAdding Social Media Share Logic From Firebase in AndroidFirebase dataSnapshot.getValue( .class) CrashFirebase datasnapshot.getValue() returns nullUpdated global variables does not reflect inside ValueEventListener's onCancelled methodHow to get the data saved in a USER_ID?Firebase offline sync => can I use condition to sync ? ANDROID
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty height:90px;width:728px;box-sizing:border-box;
I am trying to obtain value from Firebase for two different children of the "users" that are "sellers" and "customers". Also these children has children that IDs of the sellers or customers.
Seller and Customer are subclasses of the User class and I have implemented all setters and getters. Here is my code that cant obtain value from database:
public class DatabaseWrapper {
private final static DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
private final static DatabaseReference usersRef = ref.child("users");
private final static DatabaseReference productsRef = ref.child("products");
private static Object retrieverObject = null;
public static User getUser(String type, String id) throws InterruptedException
CountDownLatch done = new CountDownLatch(1);
usersRef.child(type).child(id).addValueEventListener(new ValueEventListener()
@Override
public void onDataChange(DataSnapshot dataSnapshot)
//Never returns getValue(Subclass.class)
if (type.equals("customers"))
retrieverObject = dataSnapshot.getValue(Customer.class);
else
retrieverObject = dataSnapshot.getValue(Seller.class);
done.countDown();
@Override
public void onCancelled(DatabaseError databaseError)
System.out.println("The read failed: " + databaseError.getCode());
);
done.await();
return (User)retrieverObject;
I deliberately make it sync code to see problem.
If I use getValue(User.class) instead of getValue(Customer.class) and getValue(Seller.class) it works but this usage obviously doesn't obtain fields that are in subclasses.
So the question is how can I retrieve subclass item from Firebase ?
java firebase firebase-realtime-database
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
add a comment |
I am trying to obtain value from Firebase for two different children of the "users" that are "sellers" and "customers". Also these children has children that IDs of the sellers or customers.
Seller and Customer are subclasses of the User class and I have implemented all setters and getters. Here is my code that cant obtain value from database:
public class DatabaseWrapper {
private final static DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
private final static DatabaseReference usersRef = ref.child("users");
private final static DatabaseReference productsRef = ref.child("products");
private static Object retrieverObject = null;
public static User getUser(String type, String id) throws InterruptedException
CountDownLatch done = new CountDownLatch(1);
usersRef.child(type).child(id).addValueEventListener(new ValueEventListener()
@Override
public void onDataChange(DataSnapshot dataSnapshot)
//Never returns getValue(Subclass.class)
if (type.equals("customers"))
retrieverObject = dataSnapshot.getValue(Customer.class);
else
retrieverObject = dataSnapshot.getValue(Seller.class);
done.countDown();
@Override
public void onCancelled(DatabaseError databaseError)
System.out.println("The read failed: " + databaseError.getCode());
);
done.await();
return (User)retrieverObject;
I deliberately make it sync code to see problem.
If I use getValue(User.class) instead of getValue(Customer.class) and getValue(Seller.class) it works but this usage obviously doesn't obtain fields that are in subclasses.
So the question is how can I retrieve subclass item from Firebase ?
java firebase firebase-realtime-database
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
add a comment |
I am trying to obtain value from Firebase for two different children of the "users" that are "sellers" and "customers". Also these children has children that IDs of the sellers or customers.
Seller and Customer are subclasses of the User class and I have implemented all setters and getters. Here is my code that cant obtain value from database:
public class DatabaseWrapper {
private final static DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
private final static DatabaseReference usersRef = ref.child("users");
private final static DatabaseReference productsRef = ref.child("products");
private static Object retrieverObject = null;
public static User getUser(String type, String id) throws InterruptedException
CountDownLatch done = new CountDownLatch(1);
usersRef.child(type).child(id).addValueEventListener(new ValueEventListener()
@Override
public void onDataChange(DataSnapshot dataSnapshot)
//Never returns getValue(Subclass.class)
if (type.equals("customers"))
retrieverObject = dataSnapshot.getValue(Customer.class);
else
retrieverObject = dataSnapshot.getValue(Seller.class);
done.countDown();
@Override
public void onCancelled(DatabaseError databaseError)
System.out.println("The read failed: " + databaseError.getCode());
);
done.await();
return (User)retrieverObject;
I deliberately make it sync code to see problem.
If I use getValue(User.class) instead of getValue(Customer.class) and getValue(Seller.class) it works but this usage obviously doesn't obtain fields that are in subclasses.
So the question is how can I retrieve subclass item from Firebase ?
java firebase firebase-realtime-database
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
I am trying to obtain value from Firebase for two different children of the "users" that are "sellers" and "customers". Also these children has children that IDs of the sellers or customers.
Seller and Customer are subclasses of the User class and I have implemented all setters and getters. Here is my code that cant obtain value from database:
public class DatabaseWrapper {
private final static DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
private final static DatabaseReference usersRef = ref.child("users");
private final static DatabaseReference productsRef = ref.child("products");
private static Object retrieverObject = null;
public static User getUser(String type, String id) throws InterruptedException
CountDownLatch done = new CountDownLatch(1);
usersRef.child(type).child(id).addValueEventListener(new ValueEventListener()
@Override
public void onDataChange(DataSnapshot dataSnapshot)
//Never returns getValue(Subclass.class)
if (type.equals("customers"))
retrieverObject = dataSnapshot.getValue(Customer.class);
else
retrieverObject = dataSnapshot.getValue(Seller.class);
done.countDown();
@Override
public void onCancelled(DatabaseError databaseError)
System.out.println("The read failed: " + databaseError.getCode());
);
done.await();
return (User)retrieverObject;
I deliberately make it sync code to see problem.
If I use getValue(User.class) instead of getValue(Customer.class) and getValue(Seller.class) it works but this usage obviously doesn't obtain fields that are in subclasses.
So the question is how can I retrieve subclass item from Firebase ?
java firebase firebase-realtime-database
java firebase firebase-realtime-database
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
edited Mar 23 at 14:26
Frank van Puffelen
251k31401428
251k31401428
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
asked Mar 23 at 8:17
Taha SevimTaha Sevim
33
33
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
[SOLVED]
Who has similar problem that is deserializing objects from Firebase, do not forget to write an empty constructor. I had only constructors with parameters, then I added empty parameter constructor to subclasses, it worked.
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
add a comment |
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[SOLVED]
Who has similar problem that is deserializing objects from Firebase, do not forget to write an empty constructor. I had only constructors with parameters, then I added empty parameter constructor to subclasses, it worked.
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
add a comment |
[SOLVED]
Who has similar problem that is deserializing objects from Firebase, do not forget to write an empty constructor. I had only constructors with parameters, then I added empty parameter constructor to subclasses, it worked.
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
add a comment |
[SOLVED]
Who has similar problem that is deserializing objects from Firebase, do not forget to write an empty constructor. I had only constructors with parameters, then I added empty parameter constructor to subclasses, it worked.
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
[SOLVED]
Who has similar problem that is deserializing objects from Firebase, do not forget to write an empty constructor. I had only constructors with parameters, then I added empty parameter constructor to subclasses, it worked.
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
answered Mar 23 at 10:03
Taha SevimTaha Sevim
33
33
add a comment |
add a comment |
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