将图像从图像 URL 保存到 MySql (Spring JPA Hibernate)

Question

我正在工作 Spring JPA Hibernate 项目并希望将图像从 Image Url 保存到 Mysql 数据库。我正在使用从 Rest Service 获取的图像 URL 传递 Orders DTO 数据。如何将图像 url 作为图像保存到数据库。我认为我们必须首先从 Url 获取图像。请解决这个问题。

订单DO.java

@Table(name = "ORDER")

public class OrderDO  implements Serializable{

    @Column(name = "ORDER_NUMBER", nullable = false)

    private String orderNumber; 

    @OneToMany(cascade = CascadeType.ALL, mappedBy="order")

    private Set<OrderItemDO> items = new HashSet<>();

}

订单项DO.java

@Table(name = "ORDER_ITEM")

public class OrderItemDO implements Serializable{   

    @Column(name = "PRODUCT_NAME",nullable = false)

    private String name;

    @Lob

    @Column(name = "IMAGE")

    private byte[] image;

    @ManyToOne(cascade=CascadeType.ALL)

    @JoinColumn(name="ORDER_ID", referencedColumnName="ID")

    private OrderDO order;

}

订单仓库.java

@Repository

public interface OrderRepository extends CrudRepository<OrderDO, Long>{

    public Page<OrderDO> findAll(Pageable pageable);    

}

OrderServiceImpl.java

public class OrderServiceImpl {

    @Autowired

    private ModelMapper modelMapper;

    @Autowired

    private OrderRepository orderRepository;

    private OrderDO map(Order dto) {

        OrderDO orderDO =  modelMapper.map(dto, OrderDO.class);

        Set<OrderItemDO> itemsDO = new HashSet<>();

        for(OrderItem item : dto.getItems()) {

            OrderItemDO itemDO = map(item);

            itemDO.setOrder(orderDO);

            itemsDO.add(itemDO);

        }

        orderDO.setItems(itemsDO);      

        return orderDO; 

    }

    public OrderItemDO map(OrderItem dto) {

        OrderItemDO itemDO = modelMapper.map(dto, OrderItemDO.class);

        return itemDO;

    }

    public Order SaveOrder(Order dto) {

        OrderDO entity = this.map(dto);

        entity = orderRepository.save(entity);

        return this.map(entity);

    }

Answer 1

在保存之前，您可以在 Rest Service 中将图像 url 转换为数据字节 [] 图像。public static byte[] convertImageByte(URL url) throws IOException {&nbsp; &nbsp; &nbsp; &nbsp; ByteArrayOutputStream baos = new ByteArrayOutputStream();&nbsp; &nbsp; &nbsp; &nbsp; InputStream is = null;&nbsp; &nbsp; &nbsp; &nbsp; try {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; is = url.openStream ();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; byte[] byteChunk = new byte[4096]; // Or whatever size you want to read in at a time.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; int n;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; while ( (n = is.read(byteChunk)) > 0 ) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; baos.write(byteChunk, 0, n);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return byteChunk;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; catch (IOException e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.err.printf ("Failed while reading bytes from %s: %s", url.toExternalForm(), e.getMessage());&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.printStackTrace ();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Perform any other exception handling that's appropriate.&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; finally {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (is != null) { is.close(); }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; return null;&nbsp; &nbsp; }

Answer 2

好的问题解决了。将图像 URL 转换为字节数组的代码如下。有关此问题的更多答案，请参阅此处public static byte[] convertImageByte(URL url) throws IOException {&nbsp; &nbsp; ByteArrayOutputStream baos = new ByteArrayOutputStream();&nbsp; &nbsp; InputStream is = null;&nbsp; &nbsp; try {&nbsp; &nbsp; &nbsp; &nbsp; is = new BufferedInputStream(url.openStream());&nbsp; &nbsp; &nbsp; &nbsp; byte[] byteChunk = new byte[4096];&nbsp; &nbsp; &nbsp; &nbsp; int n;&nbsp; &nbsp; &nbsp; &nbsp; while ( (n = is.read(byteChunk)) > 0 ) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; baos.write(byteChunk, 0, n);&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; return baos.toByteArray();&nbsp; &nbsp; }&nbsp; &nbsp; catch (IOException e) {e.printStackTrace ();}&nbsp; &nbsp; finally {&nbsp; &nbsp; &nbsp; &nbsp; if (is != null) { is.close(); }&nbsp; &nbsp; }&nbsp; &nbsp; return null;}将 Dto 保存到数据库时if(dto.getImageUrl() != null) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; try {&nbsp; &nbsp; URL imageUrl = new URL(dto.getImageUrl());&nbsp; &nbsp; itemDO.setImage(convertImageByte(imageUrl));&nbsp; &nbsp; &nbsp; &nbsp; } catch (IOException e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.printStackTrace();&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; entity = orderItemRepository.save(itemDO);从数据库中获取图像public byte[] getImageForOrderItem(long itemId) {&nbsp; &nbsp; Optional<OrderItemDO> option = orderItemRepository.findById(itemId);&nbsp; &nbsp; if(option.isPresent()) {&nbsp; &nbsp; &nbsp; &nbsp; OrderItemDO itemDO = option.get();&nbsp; &nbsp; &nbsp; &nbsp; if(itemDO.getImage() != null) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; byte[] image = itemDO.getImage();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return image;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; return null;}通过 Rest API 调用 Image Response@GetMapping(path="/orderItem/image/{itemId}")@ResponseStatus(HttpStatus.OK)public void getImageForOrderItem(@PathVariable("itemId") long itemId, HttpServletResponse response) {&nbsp;&nbsp; &nbsp; byte[] buffer = orderServiceImpl.getImageForOrderItem(itemId);&nbsp; &nbsp; if (buffer != null) {&nbsp; &nbsp; &nbsp; &nbsp; response.setContentType("image/jpeg");&nbsp; &nbsp; &nbsp; &nbsp; try {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; response.getOutputStream().write(buffer);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; response.getOutputStream().flush();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; response.getOutputStream().close();&nbsp; &nbsp; &nbsp; &nbsp; } catch (IOException e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.printStackTrace();&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp;}