liushuai’s note

import java.util.ArrayList;
import java.util.List;

public class  {
    
    private List<Person> list = new ArrayList<>();

    public List<Person> findByName(String name) {
        return find(new Criteria() {
            
            public boolean matches(Person person) {
                return name.equals(person.getName());
            }
        });
    }

    public List<Person> findByGender(String gender) {
       return find(new Criteria() {
           
           public boolean matches(Person person) {
               return gender.equals(person.getGender());
           }
       });
    }

    public List<Person> find(Criteria criteria){
        List<Person> people = new ArrayList<>();
        for (Person p : list){
            if(criteria.matches(p)){
                people.add(p);
            }
        }
        return people;
    }

}

interface Criteria{
    boolean matches(Person person);
}