java 8 stream으로 join을 걸어서 추출하기

Main.java

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Main{


    public static void main(String []args){
        System.out.println("Hello World");

        List<Person> persons = new ArrayList();
        List<Student> students = new ArrayList();

        persons.add(new Person(1,"원영"));
        persons.add(new Person(2,"two"));
        persons.add(new Person(3,"one"));
        persons.add(new Person(4,"apple"));
        persons.add(new Person(5,"mod"));
        persons.add(new Person(6,"hell"));
        persons.add(new Person(7,"hello"));

        students.add(new Student(10,"홍길동"));
        students.add(new Student(20,"apple"));
        students.add(new Student(30,"one"));
        students.add(new Student(40,"two"));
        students.add(new Student(50,"second"));
        students.add(new Student(60,"sorry"));
        students.add(new Student(70,"hello"));


        List<Person> result = persons.stream()
                        .filter(e -> students.stream().map(Student::getStudentName).anyMatch(name -> name.equals(e.getPersonName())))
                        .collect(Collectors.toList());

        for(Person p : result){
            System.out.println(p.getSid()+" "+p.getPersonName());
        }


    }
}
class Student{
    int id;
    String studentName;
    Student(int id, String studentName){
        this.id = id;
        this.studentName = studentName;
    }
    int getId(){return this.id;}
    String getStudentName(){return this.studentName;}
}
class Person{
    int id;
    String personName;
    Person(int id, String personName){
        this.id = id;
        this.personName = personName;
    }
    int getSid(){return this.id;}
    String getPersonName(){return this.personName;}
}