java8 --- Predicate meaning of the code

 

 // To remove this function DiyInterface interfaces, generic functions can be used as an alternative interface Predicate: https://blog.csdn.net/u011848397/article/details/89074794 
    public  class The people2 {
         Private List <the Person> persons = new new the ArrayList <> ();
         public List <the Person> getMaleList (the Predicate <the Person> the predicateA) { // common function interface 
            List <the Person> = RES new new the ArrayList <> (); 
            persons.forEach (Person -> {
                 IF (the predicateA. Test (Person)) { // abstract method called the Predicate Test 
                    res.add (Person); 
                } 
            }); 
            return res;
        }
    }

    //还原：
    interface DiyInterface {
         boolean test(Person person);
    }
    public class People {
        private List<Person> persons= new ArrayList<Person>();
        public List<Person> getMaleList(DiyInterface filter) {//自定义函数式接口
            List<Person> res = new ArrayList<>();
            persons.forEach((Person person) -> {
                if(filter.test (Person)) {
                     //Method call PersonInterface 
                    res.add (Person); 
                } 
            }); 
            return RES; 
        } 
    } 
   
    public  class the Person { 
    }