Downloading list from Firebase using 'gdx-fireapp' returns list of objects with empty fields

I'm trying to deal with Firebase in a LibGdx app using gdx-fireapp library.

I followed the given examples from here.
I have problems with "dowloading a list" sample:

I created the POJO "user" class and wrote successfully a user in database...so database contains a list of 1 user with all fields filled in (verified in database console).

Now when I try to download the list of users with the exact given code, I get a list with 1 user (OK), which all fieds are NULL

Here is the "user" POJO class

public class UserPOJO
public String username;
public String email;
public UserPOJO()
public UserPOJO(String username, String email)
this.username = username;
this.email = email;




And here is the code to retrieve the list of users :

public static void readUsersJava ()
GdxFIRDatabase.instance().inReference("users")
.filter(FilterType.LIMIT_FIRST, 5)
.readValue(List.class, new DataCallback<List<UserPOJO>>()
@MapConversion(UserPOJO.class)
@Override
public void onData(List<UserPOJO> list)
Gdx.app.log("Firebase Java", "read users OK");

@Override
public void onError(Exception e)
Gdx.app.log("Firebase Java", "read users KO");

);



As I know the user's Id, I can try to read if from database with

GdxFIRDatabase.instance().inReference("users/Xc4x0IOm...")
.readValue(UserPOJO.class, new DataCallback<UserPOJO>() ...


but doing this, i get "java.lang.ClassCastException: java.util.HashMap cannot be cast to UserPOJO".

This is probably why fields are empty : can't cast... But I can't find how to get rid of this error

Can somebody help me please ?

1 Answer
1

OK I found this :
the query answer is a Hashmap<String, Hashmap<String, String>>

Hashmap<String, Hashmap<String, String>>

so I had to :

so the code looks like this : (no change on 'user' class)

public static void readUsersJava ()
setUsersMapConverter()
GdxFIRDatabase.instance().inReference("users")
.orderBy(OrderByMode.ORDER_BY_KEY, null)
.filter(FilterType.LIMIT_FIRST, 5)
.readValue(List.class, new DataCallback<List<UserPOJO>>()
...
);



and

fun setUsersMapConverter()
GdxFIRDatabase.instance().setMapConverter(object : FirebaseMapConverter
override fun <T : Any?> convert(map: MutableMap<String, Any>, wantedType: Class<T>): T
val element = (map.get(map.keys.first())) as HashMap<String, String>
return UserPOJO(element.get("displayName"), element.get("email")) as T

// Should be inversion of convert (needed only by GWT platform)
override fun unConvert(`object`: Any): Map<String, Any>?
return null

)



Hope that can help.

Let me know if you find a better solution.

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