List collection ----- use Stream to remove duplicate entries

Java8 removed using Stream Interface between duplicate set

 

java.util.stream

Public Interface Stream<T>

extends BaseStream<T,Stream<T>>

 

        Student s1 = new Student(1,20,"Bob");
        Student s2 = new Student(2,20,"Jim");
        Student s3 = new Student(3,20,"Tom");
        Student s4 = new Student(4,20,"Jack");

        List<Student> listC = new ArrayList<>();
        listC.add(s1);
        listC.add(s2);
        listC.add(s3);
        List<Student> listD = new ArrayList<>();
        listC.add(s1);
        listC.add(s2);
        listC.add(s4);    

① Set to use the content of the collection is not repeated de-emphasis

 Set<Student> set = new HashSet<>(listC);
        set.addAll(listD);
        List<Student> list = new ArrayList<Student>(set);
        System.out.println(list);

② to re-use the Stream interfaces

 List<Student> studentList = Stream.of(listC,listD).flatMap(Collection::stream).distinct().collect(Collectors.toList());
        System.out.println(studentList);

 

static <T> Stream<T> of(T... values)

Sequential ordering elements are returned to their specified flow value.

<R> Stream<R> flatMap(Function<? super T,? extends Stream<? extends R>> mapper)

Returns the content stream by mapping by the mapping function provided to each element generated by replacing each element of the results of the flow stream.