what is hashmap in java stackoverflow code example
Example 1: java 8 hashmap example stackoverflow
Optional<List> o = id1.entrySet()
.stream()
.filter( e -> e.getKey() == 1)
.map(Map.Entry::getValue)
.findFirst();
Example 2: java 8 hashmap example stackoverflow
List<List> list = id1.entrySet()
.stream()
.filter(.. some predicate...)
.map(Map.Entry::getValue)
.collect(Collectors.toList());