Java8 Stream : Collect elements after a condition is met

Question

My POJO is as follows

class EventUser {   private id;   private userId;   private eventId; } 

I retrieve EventUser object as follows:

List<EventUser> eventUsers = eventUserRepository.findByUserId(userId); 

Say the 'eventUsers' is as follows:

[ {"id":"id200","userId":"001","eventId":"1010"}, {"id":"id101","userId":"001","eventId":"4212"}, {"id":"id402","userId":"001","eventId":"1221"}, {"id":"id301","userId":"001","eventId":"2423"}, {"id":"id701","userId":"001","eventId":"5423"}, {"id":"id601","userId":"001","eventId":"7423"} ] 

Using streaming, and without using any intermediate variable , how can I filter and collect events after a given EventUser.id: ex:

List<EventUser> filteredByOffSet = eventUsers.stream.SOMEFILTER_AND_COLLECT("id301"); 

the result should be :

[{"id":"id301","userId":"001","eventId":"2423"}, {"id":"id701","userId":"001","eventId":"5423"}, {"id":"id601","userId":"001","eventId":"7423"}] 

Answer 1

In Java 8 you need a stateful filter

public static <T> Predicate<T> from(Predicate<T> test) {     boolean[] found = { false };     // once found, always true     return t -> found[0] || (found[0] = test.test(t)); } 

NOTE: this only makes sense for single threaded streams.

List<EventUser> filteredByOffSet =       eventUsers.stream()                .filter(from(e -> "id301".equals(e.getId()))                .collect(Collectors.toList());