java - Jackson 序列化列表实体(将字段添加到根列表)

Question

这是我的实体

@Entity
public class Product extends AbstractBaseEntity {

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   @Type(type = "objectid")
   private String id;
   private String title;

我的资源

@Path(value = ApiConstant.Urls.PRODUCTS)
public class ProductResource {

   @Inject
   private ProductService productService;

   @GET
   @Path(value = ApiConstant.Urls.PRODUCTS)
   @Produces(value = MediaType.APPLICATION_JSON)
   public List getProducts(){
      return productService.findAll();
   }

我的 json 响应

[ {
  "id" : "596b6a02f70a0878590bcf08",
  "title" : "test1",
  "description" : "description test 1"
}, {
  "id" : "596b6b00f70a087b72d377eb",
  "title" : "test1",
  "description" : "description test 1"
}, {
  "id" : "596b6b75f70a087d40f580d5",
  "title" : "test1",
  "description" : "description test 1"
} ]

我想创建一个计数字段来计算列表中的项目像这样并将列表添加到结果字段

{
    "count": 3,
    "results":  [ 
     {
      "id" : "596b6a02f70a0878590bcf08",
      "title" : "test1",
      "description" : "description test 1"
    }, {
      "id" : "596b6b00f70a087b72d377eb",
      "title" : "test1",
      "description" : "description test 1"
    }, {
      "id" : "596b6b75f70a087d40f580d5",
      "title" : "test1",
      "description" : "description test 1"
    } ], 
}

我想序列化jpa持久化返回的Product List

Answer 1

您可以使用以下类来包含计数以及 Product 实体列表:

public class ResultList {
    private int count;
    @JsonProperty("results") private List<Product> products;

    public List<Product> getProducts() {
        return products;
    }

    public void setProducts(List<Product> products) {
        this.products = Objects.requireNonNull(products, "products");
        this.count = products.size();
    }

    public int getCount() {
        return count;
    }
}