我有2个实体:
@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString(exclude = "products")
@Entity
@Table(name = "categories")
public class Category {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String categoryName;
private String categoryType;
@OneToMany(mappedBy = "category", cascade = CascadeType.ALL)
private List<Product> products;
}
和第二实体:
@Data
@AllArgsConstructor
@NoArgsConstructor
@Entity
@Table(name = "products")
public class Product {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String productName;
private String productDescription;
@ManyToOne()
private Category category;
}
我有每个实体的2个存储库:
@Repository
public interface ProductRepository extends JpaRepository<Product, Long> {
}
@Repository
public interface CategoryRepository extends JpaRepository<Category, Long> {
}
然后,我将此JSON发送给Cintroller,并注意保存所有产品:
{
"products": [{
"productName": "product1",
"productDescription": "productDescription1",
"category": {
"categoryName": "catName1",
"categoryType": "type1"
}
},
{
"productName": "product2",
"productDescription": "productDescription2",
"category": {
"categoryName": "catName1",
"categoryType": "type1"
}
},
{
"productName": "product3",
"productDescription": "productDescription3",
"category": {
"categoryName": "catName2",
"categoryType": "type2"
}
}]
}
然后我需要保存它:
@PostMapping(value = "test")
public Category test(@RequestBody() RequestTest products) {
List<Product> productList = products.getProducts();
for (Product product : productList) {
//save all
}
}
类别没有ID,当我获得此JSON时,我需要创建所有产品和设置类别,但是我没有类别ID,如果我下一步:
for (Product product : productList) {
Category category = product.getCategory();
Category save = categoryRepository.save(category);
product.setCategory(save);
productRepository.save(product);
}
我为每种产品创建新的CTEGORE,我得到了:
49 catName1 type1
51 catName1 type1
53 catName2 type2
cat_id
50 productDescription1 product1 49
52 productDescription2 product2 51
54 productDescription3 product3 53
但我需要:
49 catName1 type1
51 catName2 type2
cat_id
50 productDescription1 product1 49
52 productDescription2 product2 49
54 productDescription3 product3 51
如果已经存在类别对象,您可能想首先找到。
您可以创建一个查询,如果类别以相同的名称和类型存在,则可以搜索搜索。如果存在,请使用该对象,该对象也将具有ID,否则请继续使用当前的代码。
在我看来,最好的方法是通过引入地图来跟踪保存的类别。
假设categoryName
是唯一的列,那么您可以做以下操作:
Map<String,Category> categoryMap = new HashMap<>();
for (Product product : productList) {
String categoryName = product.getCategory().getCategoryName();
Category category = categoryMap.get(categoryName);
if(category == null){
category = categoryRepository.save(product.getCategory());
categoryMap.put(categoryName,category);
}
product.setCategory(save);
productRepository.save(product);
}
首先插入所有唯一类别,并在数据库中检查同一类别。确保类别应该是唯一的。