如何从 ArrayList 中获取数据，该 ArrayList (Java) 中存储另一个数组？

Question

I have an ArrayList and this ArrayList have other array inside, I need to obtain the data inside this other array.

This is the structure of the ArrayList and the data inside, I need to get that data

This is the code that I use for get all the ArrayList but I need to get the other array that is store in the index(0) and when I can get this data I need to store it in an new Array

 if (msg.equals("warning")) {
    ArrayList<String> dataWarn = (ArrayList<String>) data;

    Log.i("api", dataWarn.toString());

Answer 1

To access the inner ArrayList:

ArrayList<String> innerList = data.get(0);

Then you can extract the data inside:

String value = innerList.get(0);

And add it to some otherList :

List<String> otherList = Arrays.asList(value);

Answer 2

You could do the following:

String[] newArray = new String[outerArray.size()];
for(int i = 0; i<outerArray.size();i++){
   newArray[i]=outerArray.get(0).get(0);
}