GitHub Copilot for Java Development

// Create a REST controller for order management

@RestController
@RequestMapping("/api/orders")
@RequiredArgsConstructor
public class OrderController {

    private final OrderService orderService;

    @GetMapping
    public ResponseEntity<List<OrderDTO>> getAllOrders(
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "10") int size) {
        Page<OrderDTO> orders = orderService.findAll(PageRequest.of(page, size));
        return ResponseEntity.ok(orders.getContent());
    }

    @PostMapping
    public ResponseEntity<OrderDTO> createOrder(@Valid @RequestBody CreateOrderRequest request) {
        OrderDTO created = orderService.create(request);
        return ResponseEntity.status(HttpStatus.CREATED).body(created);
    }

    @GetMapping("/{id}")
    public ResponseEntity<OrderDTO> getOrder(@PathVariable Long id) {
        return orderService.findById(id)
                .map(ResponseEntity::ok)
                .orElse(ResponseEntity.notFound().build());
    }
}

// Create a repository for product search

@Repository
public interface ProductRepository extends JpaRepository<Product, Long> {

    List<Product> findByCategory(String category);

    @Query("SELECT p FROM Product p WHERE p.price BETWEEN :min AND :max")
    List<Product> findByPriceRange(@Param("min") BigDecimal min, @Param("max") BigDecimal max);

    @Query("SELECT p FROM Product p WHERE LOWER(p.name) LIKE LOWER(CONCAT('%', :search, '%'))")
    Page<Product> searchByName(@Param("search") String search, Pageable pageable);

    @Modifying
    @Query("UPDATE Product p SET p.stock = p.stock - :quantity WHERE p.id = :id AND p.stock >= :quantity")
    int decrementStock(@Param("id") Long id, @Param("quantity") int quantity);
}