Hashmap with Streams in Java 8 Streams to collect value of Map

Question

Let consider a hashmap

Map id1 = new HashMap();

I inserted some values into both hashmap.

For

Answer 1

You can also do it like this

public Map> getpartitionMap(List studentsList) {

    List> allPredicates = getAllPredicates();
    Predicate compositePredicate =  allPredicates.stream()
                             .reduce(w -> true, Predicate::and)
     Map> studentsMap= studentsList
                .stream()
                .collect(Collectors.partitioningBy(compositePredicate));
    return studentsMap;
}

public List getValidStudentsList(Map> studentsMap) throws Exception {

    List validStudentsList =  studentsMap.entrySet()
             .stream()
             .filter(p -> p.getKey() == Boolean.TRUE)
             .flatMap(p -> p.getValue().stream())
             .collect(Collectors.toList());

    return validStudentsList;
}

public List getInValidStudentsList(Map> studentsMap) throws Exception {

    List invalidStudentsList = 
             partionedByPredicate.entrySet()
             .stream()
             .filter(p -> p.getKey() == Boolean.FALSE)
             .flatMap(p -> p.getValue().stream())
             .collect(Collectors.toList());

    return invalidStudentsList;

}

With flatMap you will get just List instead of List>.

Thanks