I’m trying to measure time when loading data using jpa and mysql in spring boot.

Product.java

@Entity
@ToString
@Builder
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Table(name = "tbl_product")
@EntityListeners(AuditingEntityListener.class)
public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long pno;
    private String pname;
    private int price;
    private String pdesc;
    private boolean delFlag;
    private Long categoryNum;

    @CreatedDate
    private LocalDateTime date;

    @Builder.Default
    private Long viewCount= Long.valueOf(0);

    @ManyToOne(fetch = FetchType.EAGER)
    private User seller;
    @ElementCollection(fetch = FetchType.EAGER)
    @Builder.Default
    private List<ProductImage> imageList = new ArrayList<>();

    public void changePrice(int price) {
        this.price = price;
    }

    public void changeDesc(String desc) {
        this.pdesc = desc;
    }

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

    public void addImage(ProductImage image) {
        image.setOrd(this.imageList.size());
        imageList.add(image);
    }

    public void addImageString(String fileName) {
        ProductImage productImage = ProductImage.builder()
                .fileName(fileName)
                .build();
        addImage(productImage);
    }

    public void clearList() {
        this.imageList.clear();
    }

    public void setSeller(User seller) {
        this.seller = seller;
    }
}

ProductImage.java

@Embeddable
@Getter
@ToString
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class ProductImage {
    private String fileName;

    private int ord;

    public void setOrd(int ord){
        this.ord = ord;
    }
}

ProductController.java

@RestController
@RequiredArgsConstructor
@RequestMapping("/api/products")
@Log4j2
@Tag(name = "Product", description = "Product API")
public class ProductController {
    private final ProductService productService;

    private final CustomFileUtil fileUtil;


    @GetMapping("/search")
    public ResponseEntity<?> searchProducts(@RequestParam String query) {
        try {
            List<ProductDTO> products = productService.searchProducts(query);
            log.info(products);
            return ResponseEntity.ok(products);
        } catch (Exception e) {
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(e.getMessage());
        }
    }
}

ProductService.java

public interface ProductService {
    List<ProductDTO> searchProducts(String query);
}

ProductServiceImpl.java

@Service
@RequiredArgsConstructor
@Slf4j
public class ProductServiceImpl implements ProductService {
    private final ProductRepository productRepository;

    private final UserRepository userRepository;

    @Override
    public List<ProductDTO> searchProducts(String query) {
        List<Product> products = productRepository.findByPnameContainingIgnoreCase(query);

        List<ProductDTO> dtoList = products.stream().map(el -> entityToDTO(el)).collect(Collectors.toList());
        return dtoList;
    }


    private ProductDTO entityToDTO(Product product) {
       ProductDTO productDTO = ProductDTO.builder()
                .pno(product.getPno())
                .pname(product.getPname())
                .pdesc(product.getPdesc())
                .price(product.getPrice())
                .seller(product.getSeller().getUserName())
                .viewCount(product.getViewCount())
                .categoryNum(product.getCategoryNum())
                .build();

        List<ProductImage> imageList = product.getImageList();

        if(imageList == null || imageList.size() == 0 ){
            return productDTO;
        }

        List<String> fileNameList = imageList.stream().map(productImage -> productImage.getFileName()).toList();

        productDTO.setUploadFileNames(fileNameList);

        return productDTO;
    }
}

ProductRepository.java

public interface ProductRepository extends JpaRepository<Product, Long> {
    List<Product> findByPnameContainingIgnoreCase(String query);
}

If the product name is “Product 1”, “Product 2”, “Product 3″… “Product 1000” and search for the word “product” as a keyword, all products will be returned in List format in 10 seconds.

However, if I use the findall() function on the Product it takes less than 1 seconds in total.

I would like to know why this API takes 10 seconds.

I also measured the time using mysql workbench and postman, but it took less than 2 seconds in total.

I solved the problem through fetch join, but even after searching, I couldn’t find why it took 10 seconds.