问题
I would like to filter out my collection using multiple filters.
Let's assume I have a list of Strings and a function filter() to filter out empty Strings.
List<String> myList = .......
Typically, I would use streams like this:
myList.stream()
.filter(elem -> filterOut(elem))
.collect(Collectors.toList());
How to apply multiple filters from a collection (List or Set) using streams?
Set<Predicate> myFilters = .....
回答1:
myList.stream()
.filter(s -> myFilters.stream().allMatch(p -> p.test(s)))
.collect(Collectors.toList());
Or if you're a fan of Guava:
com.google.common.base.Predicate<String> combined = Predicates.and(Iterables.transform(myFilters, p -> p::test));
myList.stream()
.filter(combined::apply)
.collect(Collectors.toList());
回答2:
Predicate combinedPredicate = myFilters.stream().reduce(Predicate::or).orElse(t -> false);
来源：https://stackoverflow.com/questions/37549121/java-8-filter-collection-using-many-filters