get an array from a map of arrays (in firestore)

Question

I'm making an android app for learning to read and write in spanish. I am trying to get a map of arrays from firestore. There, I have a document with a field called "levels" that contains the map. Like this:

levels: { 1: "papa", "mama", 2: "mapa", 3: "cama","casa" }

see firebase data structure here

I'm getting the map this way:

HashMap <String, String[]> levelsMap = new HashMap<String, String[]>();
levelsMap = (HashMap<String, String[]>) documentSnapshot.get("levels");

So far, when debugging, the map has been correctly gotten and put in the levelsMap variable.

The debugger shows it like this:

see debugger screenshot here

levelsMap={HashMap@13651} size:3

"1" -> {ArrayList@13656}  size = 2
  key = "1"
  value = {ArrayList@13656}  size = 2
    0 = "papa"
    1 = "mama"

"2" -> {ArrayList@13673}  size = 1
 key = "2"
 value = {ArrayList@13673}  size = 1
  0 = "mapa"

"3" -> {ArrayList@13675}  size = 1
 key = "3"
 value = {ArrayList@13675}  size = 1
  0 = "cama"

Then, when I try to get an array out from the levelsMap, as the debugger says it's an arrayList I try to get it with the following line

List<String> levels = levelsMap.get("1");

but android studio points an error. It says that the variable "levels" expects a List but it is getting an Array. So then I try the following (as android studio suggests)

String[] level1 = levelsMap.get("1");

This time android studio points no error, but the app crashes at that line. the error in the console says:

java.lang.ClassCastException: java.util.ArrayList cannot be cast to java.lang.String[]

So, neither of those lines seem to work. Then, how can I get the level array?

Answer 1

List<Map<String, Object>> levels = (List<Map<String, Object>>) doccumentSnapshot.get("levels");
List<String> name = Arrays.asList(levels.get("1"));

Answer 2

Finally: I solved it with these lines:

levelsMap = new HashMap<String, List<String>>();
levelsMap = (HashMap<String, List<String>>) documentSnapshot.get("levels");

then, to get a whole level array:

List<String> level1 = levelsmap.get("1");

result: level1 = {0:papa, 1:mama}

then, to get a single word:

String word = levelsmap.get("1").get(0);

result: word = papa