如何在Spring RestController中使用ResponseEntity返回具有多个属性的Json


How to return Json with Multiple properties by using ResponseEntity in Spring RestController

我正在编写Springrest学习服务。我想从控制器返回动态响应(具有多个属性的Json)。例如，我有一个方法，默认情况下，我使用消息转换器将产品列表和Spring返回，将其转换为Json。运行正常。

1
2
3
4
5
6
7
@RequestMapping(value = {"" }, method = RequestMethod.GET)
public ResponseEntity< ? > greet(@PathVariable Optional<Integer> productId) {

    List<Products> products = productService.findAllCategories();
    int count = products.size(); // also want to include this as count like below response
    return new ResponseEntity<List<Products>>(products, HttpStatus.OK);
}

现在我要像这样回复杰森

1
2
3
4
5
6
7
{
 "count": 23,
 "products":[
     {..},
     {..}
   ]
}

显示列表计数。我如何返回这样的响应。或指导我获得场景的最佳实践，例如返回具有多个属性的Json。

相关讨论

仅需一点点改进就可以实现您想要的。

为产品创建package。

之类的东西

1
2
3
4
5
6
7
8
class ProductsDTO {

  private int count;
  private List<Products> products;

  /* create setters and getters for the fields */

}

，然后在您的REST调用中

1
2
3
4
5
6
7
8
9
10
@RequestMapping(value = {"" }, method = RequestMethod.GET)
public ResponseEntity< ? > greet(@PathVariable Optional<Integer> productId) {

List<Products> products = productService.findAllCategories();
int count = products.size();
ProductsDTO productsDTO = new ProductsDTO();
productsDTO.setCount(count);
productsDTO.setProducts(products);
return new ResponseEntity<ProductsDTO>(productsDTO, HttpStatus.OK);
}

编辑：

@Shams Tabraiz Alam
-不确定您要形成的结果类型是否正确，因为当您说计数和列出时，您返回的是实体(产品)列表和计数结果(产品计数，产品列表]。不确定添加其他数据的目的，因为它删除了返回列表的实际含义并将其计为结果。无论如何，这就是我的意思。

根据您的情况，如果您不想使用DTO并使用地图添加所需的任意多个属性，我已经制作了一个示例代码(行家方式)

添加Spring和其他现有依赖项，然后将Jackson依赖项添加到pom.xml

1
2
3
4
5
6
7
8
9
10
  <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      jackson-core</artifactId>
      <version>2.8.5</version>
  </dependency>
  <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      jackson-databind</artifactId>
      <version>2.8.5</version>
  </dependency>

并有一个REST控制器

1
2
3
4
5
6
7
8
9
10
11
12
@RequestMapping(value ="/locations", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity< ? > getAll() {
    List<Location> locations  = locationService.getLocations();
    List<Country> countries = countryService.getCountries();

    Map<String, Object> result = new HashMap<String,Object>();
    result.put("count",locations.size());
    result.put("locations",locations);
    result.put("countries",countries);
    // Add any additional props that you want to add
    return new ResponseEntity<Map<String,Object>>(result, HttpStatus.OK);
}

在本地Web服务器(端口8080)中构建和部署代码，或者使用maven在命令行中运行-mvn tomcat7：run

测试..

  • 命令行-

    1
     curl -H"Accept: application/json" -H"Content-type: application/json" -X GET http://localhost:8080/api/locations

  • 浏览器

    • http：// localhost：8080 / api / locations

    完整的代码在这里-https://github.com/satya-j/loco

    相关讨论

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    @RestController
    @RequestMapping("/api")
    public class RestApiController {
        @Autowired
        RepoCity repoCity;

        @Autowired
        RepoCountry repoCountry;

        @Autowired
        RepoLanguage repoLanguage;

        @GetMapping("/allTotal")
        public Map actionAllTotal() {
            Map map = new HashMap();
            map.put("repoCity",repoCity.count());
            map.put("repoCountry",repoCountry.count());
            map.put("repoLanguage",repoLanguage.count());
            Map result = new HashMap();;
            result.put("result",map);
            return result;
        }

        @GetMapping("/country-detail/{id}")
        public Map actionCountryDetail(@PathVariable("id") String id) {
            Map result = new HashMap();
            result.put("result",repoCountry.findOne(id));
            return result;
        }
    }

    Output

    enter

    相关讨论

    我已经完成了此操作，但是我不知道这是否是一个好习惯。

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    @RequestMapping(value = {"/{productId}","" }, method = RequestMethod.GET)
    public ResponseEntity< ? > greet(@PathVariable Optional<Integer> productId) {
        List<Products> products = productService.findAllCategories();

        HashMap<String, Object> hmap = new HashMap<String, Object>();
        hmap.put("count", products.size());
        hmap.put("products", products);
        // Now I can put as many properties as I want

        return new ResponseEntity<HashMap<String, Object>>(hmap, HttpStatus.OK);
    }
    相关讨论

    1
    2
    3
    4
    5
    6
    7
    8
    9
    @RequestMapping(value ="/{pid}", method = RequestMethod.GET, produces =  MediaType.APPLICATION_JSON_VALUE)
      public ResponseEntity<Map<String, Object>> greet(@PathVariable(value ="pid", required = false) Integer productId) {
      Map<String, Object> result = new HashMap<String,Object>();
      result.put("count",locations.size());
      result.put("locations",locations);
      result.put("countries",countries);

      return ResponseEntity.ok(result);
    }