比较器：此语言级别不支持方法引用吗？

Question

I wrote the following line of code for a Java 8 project:

Comparator<Person> oldestPerson= Comparator.comparing(Person::getOldestBirthday);

It is a simple comparator, however I am trying to use this code In a project that only uses Java 7 , therefore giving this error:

"Method references are not supported at this language level"

I understand im getting the error as im not using Java 8. Is there a simple way to re-write the logic without having to use a method reference?

Answer 1

Comparator<Person> comparator = new Comparator<Person>() {
    @Override
    public int compare(Person p1, Person p2) {
        return p1.getOldestBirthday().compareTo(p2.getOldestBirthday());
    }
};

This is probably the simplest way to do it in Java 7