如何从本机查询构建json

Question

我编写的应用程序需要json格式的数据，但获取的数据没有标题

型号：

package intj.frontend.sellkon.model;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

import javax.persistence.*;

@Entity
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Table(name = "Products")
public class ProductModel {

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

    @Column(name = "Category")
    private String category;

    @Column(name = "ProductName")
    @Lob
    private String productName;

    @Column(name = "Price")
    private int price;

    @Column(name = "Slider")
    private Boolean slider;

    @Column(name = "SpecialOffer")
    private Boolean specialOffer;

    @Column(name = "NewPrice")
    private int newPrice;

    @Column(name = "FullDescription")
    @Lob
    private String fullDescription;

    @Column(name = "Image")
    @Lob
    private String image;
}

存储库：

package intj.frontend.sellkon.repository;
import intj.frontend.sellkon.model.ProductModel;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface ProductRepository extends JpaRepository<ProductModel,Long> {

    @Query(value = "select id,image,product_name,price,new_price from products where slider is true", nativeQuery = true)
    List<String> getSliderContent();
}

服务

package intj.frontend.sellkon.Service;

import intj.frontend.sellkon.repository.ProductRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

@Service
public class ProductService {

    @Autowired
    private ProductRepository productRepository;

    public List<String> getSliderContent(){
        List<String> lstMovie = new ArrayList<>();
        lstMovie = productRepository.getSliderContent();
        return lstMovie;
    }
}

控制器：

package intj.frontend.sellkon.Controller;
import intj.frontend.sellkon.Service.ProductService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@CrossOrigin("*")
@RestController
@RequestMapping("/products")
public class ProductController {
    @Autowired
    private ProductService productService;

    @GetMapping("/sl")
    public List<String> getSliderContent(){
        List<String> ls = productService.getSliderContent();
        return ls;
    }
}

在输出上，我得到以下数据：

["1,https://cdn.x-kom.pl/i/setup/images/prod/big/product-new-big,,2021/10/pr_2021_10_8_14_22_27_699_08.jpg,Acer Swift 3 i5-1135G7/16GB/512/W11 Srebrny Intel Evo,4800,4500"]

但我需要这种格式的数据：

["id: 1, image: 'https://cdn.x-kom.pl/i/setup/images/prod/big/product-new-big,,2021/10/pr_2021_10_8_14_22_27_699_08.jpg',product name: 'Acer Swift 3 i5-1135G7/16GB/512/W11 Srebrny Intel Evo', price: 4800,new_price: 4500"]

有人能解释一下怎么做吗？我认为问题是因为我返回了字符串，但如何用本机查询返回Json对象呢？

Answer 1

如果以String的形式返回数据，则只会得到值，而不是列，因此必须在列表中传递ProductModel，而不是String。

下面是修改后的代码：

存储库

@Repository
public interface ProductRepository extends JpaRepository<ProductModel,Long> {

    @Query(value = "Select id, image, product_name, price, new_price from products WHERE slider = ?", nativeQuery = true)
    List<ProductModel> getSliderContent(Boolean slider);
}

服务

@Service
public class ProductService {

    @Autowired
    private ProductRepository productRepository;

    public List<ProductModel> getSliderContent(Boolean slider){
        return productRepository.getSliderContent(slider);
    }
}

控制器

@RequestMapping("/products")
public class ProductController {
    @Autowired
    private ProductService productService;

    @GetMapping("/sl")
    public ResponseEntity<List<ProductModel>> getSliderContent(){
        List<ProductModel> ls = productService.getSliderContent("true");
        return ls;
    }
}