CODEWITHSUNDEEP
javaandroidfirebasefirebase-realtime-database
Felay
Felay

Reputation: 221

Search data in Firebase | android

I have app and I am using Firebase Realtime database. I need get all data from Search and using this code:

      myRef = FirebaseDatabase.getInstance().getReference();
  Query query = myRef.orderByChild("Search");
  query.addValueEventListener(new ValueEventListener() {
      @Override
      public void onDataChange(DataSnapshot dataSnapshot) {
          GenericTypeIndicator<ArrayList<String>> t = new GenericTypeIndicator<ArrayList<String>>(){};
          test2 = dataSnapshot.getValue(t);

I need to get it all in ArrayList, but now i am getting below exception

com.google.firebase.database.DatabaseException: Expected a List while deserializing, but got a class java.util.HashMap

Database structure:

view structure

How can I fix this? I need to get all data from Search in ArrayList. If you need I can post all code from activity and logs.

Json:

{
  "Search" : [ "Eggs", "Milk", "Apples", "Carrot", "Sugar", "Potato" ]
}

Upvotes: 2

Views: 904

Answers (1)

Alex Mamo
Alex Mamo

Reputation: 138824

Assuming that the object node is a direct child of your Firebase database root, to solve this, please use the following code:

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference searchRef = rootRef.child("object").child("Search");
ValueEventListener valueEventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        List<String> list = new ArrayList<>();
        for(DataSnapshot ds : dataSnapshot.getChildren()) {
            String value = ds.getValue(String.class);
            list.add(value);
        }
        Log.d("TAG", list.toString());
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {}
};
searchRef.addListenerForSingleValueEvent(valueEventListener);

The output will be:

Eggs
Milk
Apples
Carrot
Sugar
Potato

Upvotes: 3

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