@Entity
@Table (name="Student")
class Student {
    @Id
    @Column (name="student_id")
    private int id;

    @Column (name="name")
    private String name;

    @OneToMany(fetch = FetchType.EAGER, mappedBy = ("student"),cascade = CascadeType.ALL)
    private Set<Book> book = new HashSet<Book>();
    ........................................................................................................
}

@Entity
@Table(name="Book")
class Book {
    @Id
    @Column (name="book_id")
    private int id;

    @Column (name="name")
    private String name;

    @ManyToOne(cascade=CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinColumn(name="student_id", nullable = false)
    private Student student;
    ........................................................................................................
}

public interface StudentRepository extends JpaRepository<Student, Integer>{
}
public interface BookRepository extends JpaRepository<Book, Integer> {
}

@Service
public class StudentServiceImpl implements StudentService {
    @Autowired
    private StudentRepository studentRepository;

    @Override
    public List<Student> getAllStudents() {
        return studentRepository.findAll();
    }
}

@Controller
public class MainController {

    private StudentService studentService;

    private BookService bookService;

    @Autowired(required = true)
    @Qualifier(value = "studentService")
    public void setStudentService(StudentService studentService) {
        this.studentService = studentService;
    }

    @Autowired(required = true)
    @Qualifier(value = "bookService")
    public void setBookService(BookService bookService) {
        this.bookService = bookService;
    }


    @RequestMapping(value="/students", method=RequestMethod.GET)
    public @ResponseBody List<Student> getStudents() {
            return studentService.getAllStudents();
    }

.................................................................

[{"id":1,"name":"Misha","book":[{"id":4,"name":"Thinking in Java",
"student":{"id":1,"name":"Misha","book":[{"id":4,"name":"Thinking in Java",
"student":{"id":1,"name":"Misha","book":[{"id":4,"name":"Thinking in Java",
"student":{"id":1,"name":"Misha","book":[{"id":4,"name":"Thinking in Java", 
"student":{"id":1,"name":"Misha","book":[{"id":4,"name":"Thinking in Java","student":....