@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Entity
@Table(name = "Users")
public class User implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    private String email;

    private String password;

    @Transient
    private transient Date loginTime;

}

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
}

@SpringBootTest
class TestRepository {

    @Autowired
    UserRepository userRepository;


    @BeforeEach
    public void init() {
        userRepository.deleteAll();
    }


    @Test
    public void testTransient() {
        User u = new User();
        u.setEmail("test@fengcaoculture.com");
        u.setLoginTime(new Date());
        userRepository.save(u);

        Assert.assertEquals(1, userRepository.findAll().size());


        try {
            // the proxy object of User is not working
            // since the field of loginTime is NOT in the database
            Object o = userRepository.getById(u.getId());
            System.out.println("[Shark]" + o);
        } catch (Exception e){
            Assert.assertTrue(e instanceof LazyInitializationException);
        }

    }




    @Test
    public void test_serializable() throws IOException, ClassNotFoundException {
        User u = new User();
        u.setEmail("test@fengcaoculture.com");
        u.setLoginTime(new Date());

        // write to file
        FileOutputStream fileOutputStream = new FileOutputStream("person.txt");
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);
        objectOutputStream.writeObject(u);
        objectOutputStream.flush();
        objectOutputStream.close();

        FileInputStream fileInputStream = new FileInputStream("person.txt");
        ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
        User u2 = (User) objectInputStream.readObject();
        objectInputStream.close();


        assertTrue(u2.getEmail().equals(u.getEmail()));
        assertNull(u2.getLoginTime());
    }
}

server.port = 8888


##################
# Mysql
##################
spring.jpa.hibernate.ddl-auto=update
spring.datasource.url=jdbc:mysql://${MYSQL_HOST:localhost}:3306/test
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name = com.mysql.cj.jdbc.Driver
spring.jpa.show-sql= false