OneToMany using a join table

Course.java

package com.hello.demo.model;

import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;

import java.io.Serializable;

@Entity
public class Course {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String name;
    private String description;

    public Course() {
    }

    public Course(String name, String description) {
        this.name = name;
        this.description = description;
    }

    @Override
    public String toString() {
        return "Course{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", description='" + description + '\'' +
                '}';
    }
}

Student.java

package com.hello.demo.model;


import jakarta.persistence.*;

import java.util.HashSet;
import java.util.Set;

@Entity
@Table(name = "students")
public class Student {
    @Id
    private String cne;
    private String name;
    private String email;
    private int age;

    @OneToMany(cascade = CascadeType.ALL)
    private Set<Course> courses = new HashSet<>();



    public Student(String cne, String name, String email, int age) {
        this.cne = cne;
        this.name = name;
        this.email = email;
        this.age = age;
    }

    public Student() {
        System.out.println("Student created");
    }

    public Set<Course> getCourses() {
        return courses;
    }

    public void setCourses(Set<Course> courses) {
        this.courses = courses;
    }

    public String getCne() {
        return cne;
    }

    public void setCne(String cne) {
        this.cne = cne;
    }

    public String getName() {
        return name;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public int getAge() {
        return age;
    }


    @Override
    public String toString() {
        return "Student{" +
                "cne='" + cne + '\'' +
                ", name='" + name + '\'' +
                ", email='" + email + '\'' +
                ", age=" + age +
                '}';
    }

    public void setAge(int age) {
        this.age = age;
    }

    public static class StudentBuilder {
        private final Student student = new Student();

        public StudentBuilder cne(String cne) {
            student.setCne(cne);
            return this;
        }

        public StudentBuilder name(String name) {
            student.setName(name);
            return this;
        }

        public StudentBuilder email(String email) {
            student.setEmail(email);
            return this;
        }

        public StudentBuilder age(int age) {
            student.setAge(age);
            return this;
        }


        public Student build() {
            return student;
        }


    }
}