LocalDateTimeRange.java

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;


public class LocalDateTimeRange<T> {

	
	List<LocalDateTime> localDateTimes;
	
	private List<RangeWrap<T>> rangeWrapList;
	
	public LocalDateTimeRange() {
		localDateTimes = new ArrayList<>();
		rangeWrapList = new ArrayList<>();
	}
	
	
	
	public void add(LocalDateTime startedAt, LocalDateTime endedAt, T wrapObj) {
		rangeWrapList.add(new RangeWrap<T>(startedAt, endedAt, wrapObj));
		
		
		localDateTimes.add(startedAt.plusSeconds(0));
		localDateTimes.add(startedAt.minusSeconds(1));
		localDateTimes.add(endedAt.plusSeconds(0));
		localDateTimes.add(endedAt.plusSeconds(1));
	}
	
	public Predicate<LocalDateTime> distinctByKey( Function<LocalDateTime, String> keyExtractor) {
		Map<Object, Boolean> map = new ConcurrentHashMap<>();
		return t -> map.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
	}
	
	
	
	public void show() {
		
		 List<LocalDateTime> timeList = localDateTimes.stream()
		.filter(distinctByKey((Function<LocalDateTime, String>)(time) ->  time.toString()))
		.sorted()
		.collect(Collectors.toList());
		;
		
		
		
		timeList.stream()
		.forEach(System.out::println);
		
		System.out.println("---");
		

		
		
		List<LocalDateTime> candidateList = timeList.stream()
		.filter( dateTime -> {
			return rangeWrapList.stream().filter( rw -> {
				
				if(dateTime.compareTo(rw.startedAt) >= 0 && dateTime.compareTo(rw.endedAt) <= 0) {
					return true;
				}
				return false;
			})
			.findFirst()
			.isPresent();
		})
		.collect(Collectors.toList());
		
		
		List<RangeWrapResult> list = new ArrayList<>();
		for (int i = 0; i < candidateList.size(); i += 2) {
			
			RangeWrapResult rr = new RangeWrapResult(candidateList.get(i), candidateList.get(i+1),  new ArrayList<>());			
			list.add(rr);
		}
		
		
		
		list.stream()
		.forEach( r -> {
			
			
			
			List<T> wrapList = rangeWrapList.stream().filter( rw -> {
				
				if(r.startedAt.compareTo(rw.startedAt) >= 0 && r.startedAt.compareTo(rw.endedAt) <= 0) {
					return true;
				}
				
				if(r.endedAt.compareTo(rw.startedAt) >= 0 && r.endedAt.compareTo(rw.endedAt) <= 0) {
					return true;
				}
				
				return false;
			})
			.map(rw -> rw.wrapObj)
			.collect(Collectors.toList());
			
			r.wrapObjList = wrapList;
			
			System.out.println(r.startedAt  + " ~ " + r.endedAt + "  " + r.wrapObjList);
			
		});
		
		
		
	}
	
	

	class RangeWrap<T> {
		
		private LocalDateTime startedAt;
		private LocalDateTime endedAt;
		private T wrapObj;
		
		public RangeWrap(LocalDateTime startedAt, LocalDateTime endedAt, T wrapObj) {
			this.startedAt = startedAt;
			this.endedAt = endedAt;
			this.wrapObj = wrapObj;
		}
		
	}
	
	
	class RangeWrapResult {
		
		private LocalDateTime startedAt;
		private LocalDateTime endedAt;
		private List<T> wrapObjList;
		
		public RangeWrapResult(LocalDateTime startedAt, LocalDateTime endedAt, List<T> wrapObjList) {
			this.startedAt = startedAt;
			this.endedAt = endedAt;
			this.wrapObjList = wrapObjList;
		}
		
	}
	
	
	
	public static void main(String... args) {
	
		
		LocalDateTime now = LocalDateTime.now();
		
		
		
		
		
		LocalDateTime as = LocalDateTime.parse("2019-03-01 15:00:00", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
		System.out.println(as);
		LocalDateTime ae = LocalDateTime.parse("2019-03-02 14:59:59", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
		System.out.println(ae);
		
		LocalDateTime bs = LocalDateTime.parse("2019-03-02 15:00:00", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
		System.out.println(bs);
		LocalDateTime be = LocalDateTime.parse("2019-03-07 14:59:59", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
		System.out.println(be);
		
		LocalDateTime cs = LocalDateTime.parse("2019-03-05 15:00:00", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
		System.out.println(cs);
		LocalDateTime ce = LocalDateTime.parse("2019-03-07 14:59:59", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
		System.out.println(ce);
		
		LocalDateTimeRange<String> a = new LocalDateTimeRange<>();
		
		a.add(as, ae, "1");
		a.add(bs, be, "2");
		a.add(cs, ce, "3");
		System.out.println();
		System.out.println();
		a.show();
		
		
		
	}
	
	
	
}