Q:

Android Studio how to get the name's user logged from the Firebase database? 

I have this code, how can i only get the name value which is logged?I only need to get the name's user logged, thx! 
 DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
    DatabaseReference usuariosRef = rootRef.child("Usuarios");
    ValueEventListener eventListener = new ValueEventListener() {
        @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for(DataSnapshot ds : dataSnapshot.getChildren()) {
            String name = ds.child("name").getValue(String.class);
            Log.d("TAG", name);
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {}
};
usuariosRef.addListenerForSingleValueEvent(eventListener);

this gets all names and i only want to get the name's user logged. 

A:

To display all the users within your database, please use the following code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference usuariosRef = rootRef.child("Usuarios");
ValueEventListener eventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for(DataSnapshot ds : dataSnapshot.getChildren()) {
            String name = ds.child("name").getValue(String.class);
            Log.d("TAG", name);
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {}
};
usuariosRef.addListenerForSingleValueEvent(eventListener);

The output will be all the names of your logged in users:
Eric
Julian Ramos
//and so on

To get the details only of a single user, please use the following code:
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = rootRef.child("Usuarios").child(uid);
ValueEventListener eventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        String name = dataSnapshotds.child("name").getValue(String.class);
        Log.d("TAG", name);
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {}
};
uidRef.addListenerForSingleValueEvent(eventListener);

So you can now display all your users from your database, or only the logged-in user.