Set<Integer> ageSet = new HashSet<>();
Map<Integer, People> map = new HashMap<>();
for(int age : ageSet{
People people = new People(age);
map.put(age, people);
}
I'm trying to create an instance and put it in Hashmap with its integer. If I would like to code this using parallelStream()(stream()), how could I do this?
I'm assuming your People class has a getAge() function.
Map<Integer, People> map = ageSet.stream()
.map(a -> new People(a))
.collect(Collectors.toMap(People::getAge, p -> p));
You can collect the stream by usng Collectors.toMap(keyMapper, valueMapper):
Map<Integer, Person> map = ageSet.stream()
.collect(Collectors.toMap(Function.identity(), Person::new));
Refer to this example using a student and id:
//set of ids
Set<Integer> idSet = new HashSet<>();
//populate some ids
for(int i=0; i<5; i++)
{
idSet.add(i);
}
//create map
Map<Integer, Student> studentMap = new HashMap<>();
//stream id list to map with students
idSet.stream().forEach(id -> studentMap.put(id, new Student(id)));
//print out
System.out.println(studentMap);
