Löschen der untergeordneten Entität aus der Gruppe in der übergeordneten Klasse

Question

Ich versuche, Bilddateien an eine Entität namens Produkt anzuhängen. Ich kann ein Produkt zusammen mit dem Bild ziemlich gut aber wenn ich versuche, ein Bild zu löschen, erhalte ich den folgenden Fehler.

HTTP 500 - Anfrageverarbeitung fehlgeschlagen; verschachtelte Ausnahme ist org.hibernate.PersistentObjectException: freistehende Einheit geführt zu beharren: com.IJM.model.Product

Produktklasse

@Entity 
@Table(name = "Product") 
public class Product { 

@Id 
@GeneratedValue(strategy = GenerationType.IDENTITY) 
@Column(name = "Id") 
private Long id; 

@NotNull 
@Size(min = 3, max = 10) 
@Column(name = "Code", nullable = false) 
private String code; 

@NotNull 
@Size(min = 3, max = 50) 
@Column(name = "Name", nullable = false) 
private String name; 

@Size(max = 50) 
@Column(name = "Description", nullable = false) 
private String description; 

@ManyToOne(cascade = CascadeType.MERGE) 
@JoinColumn(name = "Id_Category") 
private Category category; 

@ManyToOne(cascade = CascadeType.MERGE) 
@JoinColumn(name = "Id_Unit") 
private Unit unit; 

@OneToMany(cascade = CascadeType.ALL, 
     fetch= FetchType.EAGER, 
     orphanRemoval = true, 
     mappedBy="product") 
private Set<Image> images; 

public String getCode() { 
    return code; 
} 

public void setCode(String code) { 
    this.code = code; 
} 

public String getDescription() { 
    return description; 
} 

public void setDescription(String description) { 
    this.description = description; 
} 
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; 
} 

public Category getCategory() { 
    return category; 
} 

public void setCategory(Category category) { 
    if(this.category==null||!this.category.equals(category)) 
    { 
     this.category=category; 
    } 
    return; 
} 

public Unit getUnit() { 
    return unit; 
} 

public void setUnit(Unit unit) { 
    if(this.unit==null||!this.unit.equals(unit)) 
    { 
     this.unit=unit; 
    } 
    return; 
} 

public Set<Image> getImages() { 
    return images; 
} 

public void setImages(Set<Image> images) { 
    this.images = images; 
} 
} 

Bildklasse

@Entity 
@Table(name = "product_Image") 
public class Image { 

@Id 
@GeneratedValue(strategy = GenerationType.IDENTITY) 
@Column(name="id", nullable = false) 
private long id; 

@Lob 
@Column(name = "File", nullable = false) 
private byte[] file; 

@Column(name = "Checksum",nullable = false) 
private String checksum; 

@Column(name = "Extension",nullable = false) 
private String extension; 

@Column(name = "File_Name",nullable = false) 
private String file_name; 

@Column(name = "Size",nullable = false) 
private int size; 

@Column(name = "Last_Updated",nullable = false) 
private Timestamp last_Updated; 


@ManyToOne(cascade=CascadeType.ALL) 
@JoinColumn(name="Id_Product") 
private Product product; 

@ManyToOne(cascade = CascadeType.MERGE) 
@JoinColumn(name="Id_Directory") 
private Directory directory; 

public long getId() { 
    return id; 
} 

public void setId(long id) { 
    this.id = id; 
} 

public byte[] getFile() { 
    return file; 
} 

public void setFile(byte[] file) { 
    this.file = file; 
} 

public String getChecksum() { 
    return checksum; 
} 

public void setChecksum(String checksum) { 
    this.checksum = checksum; 
} 

public String getExtension() { 
    return extension; 
} 

public void setExtension(String extension) { 
    this.extension = extension; 
} 

public String getFile_name() { 
    return file_name; 
} 

public void setFile_name(String file_name) { 
    this.file_name = file_name; 
} 

public int getSize() { 
    return size; 
} 

public void setSize(int size) { 
    this.size = size; 
} 

public Timestamp getLast_Updated() { 
    return last_Updated; 
} 

public void setLast_Updated(Timestamp last_Updated) { 
    this.last_Updated = last_Updated; 
} 

public Product getProduct() { 
    return product; 
} 

public void setProduct(Product product) { 
    this.product = product; 
} 

public Directory getDirectory() { 
    return directory; 
} 

public void setDirectory(Directory directory) { 
    this.directory = directory; 
} 

Und das ist der Code für Der Controller ruft die Löschmethode

@RestController 
@RequestMapping("/image") 
public class ImageController { 

@Autowired 
ProductService productService; 

@Autowired 
ImageService imageService; 

private static final String productImagePath="C:\\IJM\\Images\\Product\\"; 

@RequestMapping(value = "/product/{code}", method = RequestMethod.DELETE) 
public ResponseEntity<Image> deleteProductImage(@PathVariable("code") String code) { 
    System.out.println("Fetching & Deleting Image for product " + code); 
    code = code.toUpperCase(); 

    if (!productService.isProductExist(code)) { 
     System.out.println("Product with code " + code + " not found"); 
     return new ResponseEntity<Image>(HttpStatus.NOT_FOUND); 
    } 
    else 
    { 
     Product product = productService.findProductByCode(code); 
     if(product.getImages()!=null) 
     { 
      for(Image image:product.getImages()) 
      { 
       product.getImages().remove(image); 
       image.setProduct(null); 
       imageService.deleteImage(image.getId()); 
      } 
      productService.saveProduct(product); 
      try{ 

       File file = new File(productImagePath+code); 

       if(FileDeleter.removeDirectory(file)){ 
        System.out.println(file.getName() + " is deleted!"); 
       }else{ 
        System.out.println("Delete operation is failed."); 
       } 

      }catch(Exception e){ 

       e.printStackTrace(); 

      } 
     } 
    } 

    return new ResponseEntity<Image>(HttpStatus.NO_CONTENT); 
} 
} 

Falls jemand anderes sich fragt .. der Dienst nur Anrufe dem DAO

@Override 
public void deleteImage(long id) { 
    Image image = imageDao.findById(id); 
    imageDao.delete(image); 

} 

Dies ist die Dao Klasse

@Repository("imageDao") 
public class ImageDaoImpl extends AbstractDao<Long,Image> implements ImageDao{ 


@Override 
public void delete(Image image) { 
    super.delete(image); 

} 
} 

Dies ist der Code in meiner abstrakten DAO Klasse

public void delete(T entity) { 
    getSession().delete(entity); 
} 

Answer 1

sie diese Linie ist nicht in der richtigen Reihenfolge scheint .

product.getImages().remove(image); 
image.setProduct(null); 
imageService.deleteImage(image.getId()); 

Auch nicht sicher, was imageService.deleteImage(image.getId()); tut. Es ist nicht notwendig.

Bitte versuchen Sie wie unten.

for(Image image:product.getImages()) 
    { 
    image.setProduct(null); 
    product.getImages().remove(image); 
    } 
productService.saveProduct(product); 

Dies sollte genug sein. Ich weiß, dass es keinen Sinn macht, die Reihenfolge zu ändern, aber es hat für mich funktioniert.