Returning Optional<Student> or Optional.empty() - java-8

Question

I'm playing a little bit with Optional to understand how it works. Let's say I have this class:
public class Student {
private int id;
private String name;
public Student(int id, String name) {
this.id = id;
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
and I want to return a Student by Id or Optional.empty if it doesn't find it. This is what I have so far:
public class Main {
static List<Student> students = new ArrayList<>();
public static void main(String[] args) {
students.add(new Student(1, "name1"));
students.add(new Student(2, "name2"));
students.add(new Student(3, "name3"));
System.out.println(getStudentById(1).get().getName());
}
public static Optional<Student> getStudentById(int id) {
return students
.stream()
.filter( s -> s.getId() == id)
.findFirst();
}
}
That works but I wanted to add this line:
.findFirst()
.orElse(Optional.empty());
and I got this:
Error:(23, 39) java: incompatible types: no instance(s) of type variable(s) T exist so that java.util.Optional conforms to com.company.Student
Also I'd like to know if that is the correct way to go over a list, I mean element by element or there is something better?

Answer 1

If you read javadocs of Stream#findFirst() you will find that you already have what you need:
Returns an Optional describing the first element of this stream, or an
empty Optional if the stream is empty. If the stream has no encounter
order, then any element may be returned.
So just do
return students
.stream()
.filter( s -> s.getId() == id)
.findFirst();