Java Map 向 postman 發送響應時省略空字符串值

Question

我的 map 是：Map<String, String>。 問題是空值不會發送到 postman 即使我在那里調試。

這是 api：

@GetMapping(value = Routes.URI_SUFFIX_DATA_ZIPCODES_BY_CITY_AND_ZIPCODE, produces = {MediaType.APPLICATION_JSON_VALUE})
@RegisterMetricCallReceived(appService = "getStreetsByCityAndZipCode", version = "v1", type = TYPE_REST)
public Map<String,String> getStreetsByCityAndZipCode(HttpServletRequest request,
                                                               @RequestParam(name = "city") String city,
                                                               @RequestParam(name = "zipcode") String zipcode) {

        GetStreetByCityAndZipcode query = new GetStreetByCityAndZipcode();
        query.setCity(city);
        query.setZipcode(zipcode);
        Map<String, String> result = service.getStreets("eligibility", query).orElse(null);
        return result;
    }

當我調試結果 object 時，是這樣的：

"PLACE DU PRIEURE" -> "01043406"
"ROUTE DE BIERNE" -> ""
"ROUTE DE GENNES SUR GLAIZE" -> "01043405"
"RUE COURTE" -> "01043399"
"RUE D ANJOU" -> "01043398"
"RUE DE GENNES" -> "04311435"
"RUE DE L EGLISE" -> "01043397"
"RUE DE LA CHENAIE" -> "04106244"
"RUE DE LA POSTE" -> "01043400"
"RUE DES GRANDS JARDINS" -> "01043401"
"RUE DES JARDINS" -> ""
"RUE DES SPORTS" -> "04415887"

但是從 postman，我沒有收到這兩個：

"ROUTE DE BIERNE" -> ""
"RUE DES JARDINS" -> ""

我只收到其他沒有空值的人：

"PLACE DU PRIEURE" -> "01043406"
"ROUTE DE GENNES SUR GLAIZE" -> "01043405"
"RUE COURTE" -> "01043399"
"RUE D ANJOU" -> "01043398"
"RUE DE GENNES" -> "04311435"
"RUE DE L EGLISE" -> "01043397"
"RUE DE LA CHENAIE" -> "04106244"
"RUE DE LA POSTE" -> "01043400"
"RUE DES GRANDS JARDINS" -> "01043401"
"RUE DES SPORTS" -> "04415887"

Answer 1

我發現了這個問題，這是由於這個 Bean 配置，當我刪除它時，它可以正常工作：

 @Bean
 public JacksonFix jacksonFix(RequestMappingHandlerAdapter 
                                           annotationMethodHandlerAdapter) {
        return new JacksonFix(annotationMethodHandlerAdapter);
 }