What are some examples of using the filter method in Java Streams API?

Can you give me some examples of using the filter method in Java Streams API?

Sure! The filter method in Java Streams API is used to filter elements based on a given predicate. For example, if you have a list of integers and you want to filter out the even numbers, you can do it like this:

List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);
List<Integer> evenNumbers = numbers.stream()
                                    .filter(n -> n % 2 == 0)
                                    .collect(Collectors.toList());

That's helpful! Can you show me another example with a custom object?

Of course! Let's say you have a list of Person objects and you want to filter out those who are older than 18. Here's how you can do it:

List<Person> people = Arrays.asList(new Person("Alice", 20), new Person("Bob", 17));
List<Person> adults = people.stream()
                            .filter(person -> person.getAge() > 18)
                            .collect(Collectors.toList());

What if I want to filter based on multiple conditions?

You can combine multiple conditions using logical operators. For example, to filter adults who are also named 'Alice':

List<Person> filtered = people.stream()
                               .filter(person -> person.getAge() > 18 && person.getName().equals("Alice"))
                               .collect(Collectors.toList());