Classroom with contains

Classroom.java

package lesson7;


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

public class Classroom {

    List<Student> students;

    public Classroom() {

        students = new ArrayList<Student>();
    }

    public void enter(Student s) {

        students.add(s);
        System.out.println("Student " + s.getName() + " " + s.getSecondName() + " enters");
    }

    public void leave(Student s) {

        students.remove(s);
        System.out.println("Student " + s.getName() + " " + s.getSecondName() + " leaves");
    }

    public int getStudentCount() {

        return  students.size();
    }

//    do not use contains();
//    public boolean isPresent(String name, String secondName) {
//
//        for (int i = 0; i < students.size(); i++) {
//            if (students.get(i).getName().equals(name) && students.get(i).getSecondName().equals(secondName)) {
//                return true;
//            }
//        }
//        return false;
//    }

    public boolean isPresent(String name, String secondName) {

        Student student = new Student();
        student.setName(name);
        student.setSecondName(secondName);
        if (students.contains(student)) {
            return true;
        }

        return false;
    }

    public void printStudentInfo() {

        for (Student s : students) {
            System.out.println(s.getName() + " " + s.getSecondName());
        }
    }

    public List<Student> getStudents() {

        return new ArrayList<Student>(students);
    }
}

Launcher1.java

package lesson7;


import java.util.Arrays;

public class Launcher1 {

    public static void main(String[] args) {

        Classroom cl = new Classroom();

        Student s1 = new Student();
        s1.setName("Alex");
        s1.setSecondName("Romanov");
        cl.enter(s1);

        Student s2 = new Student();
        s2.setName("Olga");
        s2.setSecondName("Bila");
        cl.enter(s2);

        Student s3 = new Student();
        s3.setName("Garik");
        s3.setSecondName("Petrov");
        cl.enter(s3);

        System.out.println("Students count: " + cl.getStudentCount());
        cl.printStudentInfo();

        System.out.println("Olga Bila is present: " + cl.isPresent("Olga", "Bila"));
        System.out.println("Olga Bila is present: " + cl.isPresent("Olga", "Bila"));
        cl.leave(s2);
        System.out.println("Olga Bila is present: " + cl.isPresent("Olga", "Bila"));

        System.out.println("Students count: " + cl.getStudentCount());

        System.out.println(Arrays.toString(cl.getStudents().toArray()));
    }
}

Student.java

package lesson7;


public class Student {

    private String name;
    private String secondName;

    public Student() {
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSecondName() {
        return secondName;
    }

    public void setSecondName(String secondName) {
        this.secondName = secondName;
    }

    @Override
    public String toString() {
        return name + " " + secondName;
    }

    @Override
    public boolean equals(Object obj) {

        if (obj instanceof Student) {
            Student s = (Student)obj;

            if (name != null && secondName != null && s.getName().equals(name) && s.getSecondName().equals(secondName)){
                return true;
            }
        }
        return false;
    }
}