"Incompatible types" error when using collect and map with java streams

Question

I have this class:

public class AirbnbListing {
...
private int price
...
public int getPrice() { return price; }

And I'm trying to use a java stream to collect the integer prices from an ArrayList of AirbnbListing objects:

ArrayList<AirbnbListing> properties = dataParser.getNeighbourhoodProperties(neighbourhood, 0, -1, 0, "All");
ArrayList<Integer> prices =
    properties.stream()
        .map(AirbnbListing::getPrice)
        .collect(Collectors.toList());

But I'm getting "Incompatiable types: inferenance variable R has incompatible bounds". Not sure what the issue is.

https://stackoverflow.com/questions/27522741/incompatible-types-inference-variable-t-has-incompatible-bounds — Stultuske, Mar 27 '19 at 06:58

score 0 · Answer 1 · answered Mar 27 '19 at 07:05

0

Create ArrayList By passing argument like.

ArrayList<Integer> prices =
    properties.stream()
        .map(AirbnbListing::getPrice)
        .collect(Collectors.toCollection(ArrayList::new));//<------- this

answered Mar 27 '19 at 07:05

Khalid Shah

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"Incompatible types" error when using collect and map with java streams

1 Answers1