Two-stream nested loop

// anyMatch():判断stream流中是否有符合匹配规则的元素，有返回true，没有返回false
List<Long> list1= new ArrayList<>();
List<Long> list2= new ArrayList<>();
list1 = list1.stream().filter(m1 -> 
			list2.stream().anyMatch(m2 ->
				m1 == m2)).collect(Collectors.toList());