public class Student
{
    @Column(primaryKey=true)
    int studentId;
    String firstName;
    String lastName;
    Date graduationDate;
    
    // studentId field establishes one to many relationship by default
    // since it is same name in both Student and Entrolled classes
    // use @OneToManyCascade to override defaults
    List<Enrolled> enrollment;
    
    getters/setters for studentId, firstName, lastName, graduationDate, and enrollment...
    
    @Override
    public String toString()
    {
        return studentId + " " + firstName + " " + lastName;
    }
}

public class Enrolled
{
    @Column(primaryKey=true)
    int enrolledId;
    int studentId;
    int courseId;
    int yr;
    int semester;
    
    getters/setters for enrolledId, studentId, courseId, yr, and semester...

    @Override
    public String toString()
    {
        return courseId + " " + yr + " " + semester;
    }
}

ArrayList<Student> list = new ArrayList<>();
ArrayList<Enrolled> enrollment;
Student student;

// student John Miller
student = new Student();
student.setStudentId(9999);
student.setFirstName("John");
student.setLastName("Miller");
list.add(student);

// 1 course for John Miller
enrollment = new ArrayList<>();
enrollment.add(enroll202(student)); // creates Enrolled object for course 202
student.setEnrollment(enrollment);

// student John Smith
student = new Student();
student.setStudentId(8888);
student.setFirstName("John");
student.setLastName("Smith");
list.add(student);

// 2 courses for John Smith
enrollment = new ArrayList<>();
enrollment.add(enroll202(student));  // creates Enrolled object for course 202
enrollment.add(enroll601(student));  // creates Enrolled object for course 601
student.setEnrollment(enrollment);

// student Rita Miller
student = new Student();
student.setStudentId(7777);
student.setFirstName("Rita");
student.setLastName("Miller");
student.setGraduationDate(new GregorianCalendar(2000, 11, 31).getTime());
list.add(student);

// no courses for Rita Miller

// inserts 3 students and their enrolled objects
System.out.println(table.insertAll(list) + " rows inserted");

3 rows inserted

Database database = new Database(getConnection(), getSchema());
Table<Student> table = database.getTable(Student.class);
System.out.println("table.selectAll():");

for (Student s: table.selectAll())
{
    System.out.println(s);
    System.out.println("  enrolled:");
    
    for (Enrolled e: s.getEnrollment())
    {
        System.out.println("  " + e);    
    }
}

table.selectAll():
7777 Rita Miller
  enrolled:
8888 John Smith
  enrolled:
  202 2011 1
  601 2012 2
9999 John Miller
  enrolled:
  202 2011 1