实体仓库扩展了JpaRepository<Entity, Id>和JpaSpecificationExecutor<Entity>，EntitySpec扩展了Specification<Entity>-PHP中文网问答

这是我的端点 http://localhost:8080/country/all 回复所有国家都可以

当我想过滤它们时返回未找到国家为空并返回异常 throw new RecordNotFoundException("无效请求，无数据返回"); 在我的数据库中有一条记录县_代码国家 KM科摩罗

这是我的 json 负载

{
     "country_code":["KM"]
    }

public interface CountryRepo extends JpaRepository, JpaSpecificationExecutor {

    }

    public final class CountrySpecs implements Specification {
    
    final private SearchCriteria criteria;
    
    public CountrySpecs(SearchCriteria searchCriteria) {
        this.criteria = searchCriteria;
    }

        @Override
        @Nullable
        public Predicate toPredicate(Root root, CriteriaQuery query, CriteriaBuilder builder) {
        switch (criteria.getOperation()) {
            case ":":
              if (root.get(criteria.getKey()).getJavaType() == String.class) {
                return builder.like(
                        root.get(criteria.getKey()),
                        "%" + criteria.getValue() + "%");
              } else {
                return builder.equal(root.get(criteria.getKey()),
                        criteria.getValue());
              }
            case "=":
              return builder.equal(root.get(criteria.getKey()),
                      criteria.getValue());
            case "in":
              return builder.in(root.get(criteria.getKey())).value(criteria.getValue());
            default:
              return null;
       }
       }
    }

     @GetMapping("/all")
     public ResponseEntity> getAll(
         @Valid @RequestBody Map request) throws Exception {
         List countries = new ArrayList<>();
 
         int page = (request.get("page") != null) ? (int) request.get("page") : 1;
         int size = (request.get("size") != null) ? (int) request.get("size") : DEFAULT_SIZE;

        // page-1 mi da la possibilità di scrivere nel payload page=1
        Pageable pageable = PageRequest.of(
           page,
          size);
        Page pageCountries = null;

       /* Validazione */

       /* filter */
       if (request.keySet().size() > 0) {
          CountrySpecs countrySpecs = null;
          if (request.keySet().contains("country_code")) {
             List list = (List) request.get("country_code");
             /* paginazione filtrata */
             countrySpecs = new CountrySpecs<>(new SearchCriteria("country_code", "in", list));
             pageCountries = repository.findAll(
               countrySpecs,
               pageable);
             countries = pageCountries.getContent();
          }
      } else {
        pageCountries = repository.findAll(pageable);
        countries = pageCountries.getContent();
      }

      if (countries.isEmpty()) {
        // la tabella interrogata non ha dati
        throw new RecordNotFoundException("无效请求，无数据返回");
      }

      Map obj = new TreeMap<>();
      // aggiunta delle informazioni sulla paginazione
      obj.put("countries", countries);
      obj.put("currentPage", pageCountries.getNumber());
      obj.put("totalItems", pageCountries.getTotalElements());
      obj.put("totalPages", pageCountries.getTotalPages());

     ResponseEntity> response = new ResponseEntity<>(
        obj,
        HttpStatus.OK);
       return response;
    }

谢谢Rashin，我已经改进了代码，但这个问题仍然存在！希望能找到解决办法。

重置代码后，它正在工作......

enter code here @GetMapping("/all") public ResponseEntity> getAll( @Valid @RequestBody Map request) { try { countryService.customPage.init(); if (request.keySet().contains("page")) { countryService.customPage.setPage(request.get("page").toString()); } if (request.keySet().contains("size")) { countryService.customPage.setSize(request.get("size").toString()); } Sort ordine=(request.keySet().contains("sort")) ? countryService.customSort.sorted((CustomSort[]) request.get("sort")) : Sort.unsorted(); // page default value 1 and size default value DEFAULT_SIZE Pageable pageable = PageRequest.of( countryService.customPage.getPage(), countryService.customPage.getSize(), ordine ); /* Validazione */ Map countries; /* filter */ if (request.keySet().contains("country_code")) { List list = (List) request.get("country_code"); countries = countryService.getByCountryCode(list, pageable); } else { countries = countryService.getAll(pageable); } //countryService restituisce empty se la pagina richiesta è maggiore di quelle presenti //se la richiesta non restituisce risultati if (countryService.isEmpty()) { if (((Integer) countries.get("currentPage")).intValue()> ((Integer) countries.get("totalPages")).intValue()) { throw new RecordNotFoundException("The page " + (countryService.customPage.getPage()+1) + " is over the total page"); } // la tabella interrogata non ha dati throw new RecordNotFoundException("Invalid request, return no data"); } ResponseEntity> response = new ResponseEntity( countries, HttpStatus.OK); return response; } catch (RecordNotFoundException | NumberFormatException re) { Map errors = new LinkedHashMap(); errors.put("errors", re.getMessage()); ResponseEntity> response = new ResponseEntity( errors, HttpStatus.INTERNAL_SERVER_ERROR); return response; } catch (Exception e) { Map errors = new LinkedHashMap(); errors.put("errors", Errors.all); ResponseEntity> response = new ResponseEntity( errors, HttpStatus.BAD_REQUEST); return response; } } /** * @param list * @param pageable * @return */ public Map getByCountryCode(List list, Pageable pageable) { /* paginazione filtrata */ Specs countrySpecs = new Specs(new SearchCriteria("country_code", "in", list)); pageCountries = repository.findAll( countrySpecs, pageable); countries = pageCountries.getContent(); Map service = new LinkedHashMap(); // aggiunta delle informazioni sulla paginazione service.put("countries", countries); service.put("currentPage", pageCountries.getNumber()+1); service.put("totalItems", pageCountries.getTotalElements()); service.put("totalForPage", pageCountries.getSize()); service.put("totalPages", pageCountries.getTotalPages()); return service; }