Java List Stream Filter
Collection
Java stream filters allow for a more succinct approach to filtering collections.
A naive approach would look something like:
List<String> collection = new ArrayList<String>();
collection.add("Ireland");
collection.add("Finland");
collection.add("France");
collection.add("Germany");
collection.add("Italy");
collection.add("Hungary");
// one could also remove, if original collection is not required to be immutable
List<String> countriesWithLand = new ArrayList<String>();
for (String c : collection) {
if (c.contains("land")) {
countriesWithLand.add(c);
}
}
A neater approach using collection streams and a filter expression:
List<String> collection = new ArrayList<String>();
collection.add("Ireland");
collection.add("Finland");
collection.add("France");
collection.add("Germany");
collection.add("Italy");
collection.add("Hungary");
List<String> countriesWithLand = collection
.stream()
.filter(c -> c.contains("land"))
.collect(Collectors.toList());
