通过Hibernate存储和检索图像

Question

我想知道在hibernate的帮助下存储图像的最佳方法是什么(进入MySQL)我有这个类Mapping

@Entity
@Table(name = "picture")
public class PictureEntity implements Serializable {

    @Id
    @Column(name = "id")
    @GeneratedValue
    private int id;
    @Column(name = "format", length = 8)
    private String format;
    //@Basic(fetch = FetchType.LAZY)
    @Lob
    @Column(name = "context", nullable = true, columnDefinition = "mediumblob")
    private java.sql.Blob myBlobAttribute; // or byte[] no diff
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "branch_fk", referencedColumnName = "id", nullable = false)
    private BranchEntity branch;

另外,我有PictureDAO; 我想知道如何实现My PictureDAO来保存和检索图像.

Answer 1

带字节数组的版本很简单.

public class PictureEntity implements Serializable {
    private byte[] imageBytes;

    public BufferedImage getImage() {
        InputStream in = new ByteArrayInputStream(imageBytes);
        return ImageIO.read(in);
    }

    public void setImage(BufferedImage image) {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ImageIO.write(image, "PNG" /* for instance */, out);
        imageBytes = out.toByteArray();
    }
}