JPA/H2 และรีโพซิทอรี

import jakarta.persistence.*;@Entity
public class User {
  @Id @GeneratedValue
  private Long id;
  private String name;
  // getters and setters
  public Long getId() { return id; }
  public void setId(Long id) { this.id = id; }
  public String getName() { return name; }
  public void setName(String name) { this.name = name; }
}

import org.springframework.data.jpa.repository.JpaRepository;
public interface UserRepository extends JpaRepository<User, Long> {}

import org.springframework.web.bind.annotation.*;import java.util.*;@RestController
@RequestMapping("/users")
public class UserController {
  private final UserRepository repo;
  public UserController(UserRepository repo) { this.repo = repo; }

  @GetMapping
  public List<User> all() { return repo.findAll(); }

  @PostMapping
  public User add(@RequestBody User u) { return repo.save(u); }
}