CODEWITHSUNDEEP
javajava-8java-stream
Logarith
Logarith

Reputation: 710

Java8 Nested Streams write back with setter

I´m trying to loop over two lists, filter the nested list and write the result back into the main object with java8 features.

locations.forEach(location -> location.getSubList().stream()
            .filter(this::correctTestDataValue)
            .collect(Collectors.toList()));

So by now the sublist inside location doesnt change, which is obvious because stream and collect do create a new list, which is not written back into the location object. So my question is, if there is a way to call the setSubList(...) method of the location object and writing the new list into it.

Thx

Upvotes: 2

Views: 1473

Answers (1)

assylias
assylias

Reputation: 328608

I would use a for loop:

for (Location location : locations) {
  List<?> newList = location.getSubList().stream()
                                         .filter(this::correctTestDataValue)
                                         .collect(Collectors.toList());
  location.setSubList(newList);
}

Or if you can remove in place:

for (Location location : locations) {
  location.getSubList().removeIf(x -> !correctTestDataValue(x));
}

Which can work as a stream:

locations.stream()
    .map(Location::getSublist)
    .forEach(list -> list.removeIf(x -> !correctTestDataValue(x)));

Upvotes: 5

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