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回复

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

我想创建一个计算列表中项目的计数字段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持久性

返回的产品列表

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;
    }
}

Answer 2

具有泛型类型的类

public class ResultList<T> {

    private int count;
    @JsonProperty("results")
    private List<T> items;

    public List<T> getItems() {
        return items;
    }

    public void setItems(List<T> items) {
        this.items = Objects.requireNonNull(items, "items");
        this.count = items.size();
    }

    public int getCount() {
        return count;
    }
}

ProductResource

@GET
@Path(value = ApiConstant.Urls.PRODUCTS)
@Produces(value = MediaType.APPLICATION_JSON)
public ResultList getProducts(){
    List products = productService.findAll();
    ResultList result = new ResultList<Product>();
    result.setItems(products);
    return result;

}

谢谢@ ck1

杰克逊序列化列表实体（将字段添加到根列表）

2 个答案: