Replace Null Values in Arraylist

Question

i'm trying to replace null values in my arrayList but I get exception

java.lang.NullPointerException

I have tried different way :

Data.replaceAll(s -> s.replaceAll(" null", "")); 

And :

for(int x = 0; x < Data.size(); x++)
          {
                if(Data.get(x).equals("null") == true)
                {
                    Data.set(x, "");
                }
          }

And :

for(int x = 0; x < Data.size(); x++)
          {
                if(Data.get(x).equals(null) == true)
                {
                    Data.set(x, "");
                }
          }

but an exception is throw java.lang.NullPointerException

Here is an exemple of my arrayList:

[0050568D6268, null, A001, A, T3, Principal, COL - Test, 4-Lock, Com. On Stage, Social, RDC, null, null, null, null, -1, null, -1, 0, -1, 99, 53]

I'm looking for any help thanks.

Answer 1

I think you want to use map() here:

// given list data
data = data.stream()
    .map(s -> Objects.isNull(s) ? "" : s)
    .collect(Collectors.toList());

This would return a list identical to the input, except with all null values replaced by empty string.