如何在 Java 中将此 JSON 解析为我的 POJO

Question

I have this JSON structure that I'm trying to parse to a Java Object but don't know what I'm missing here.

{
   "response":{
      "status":1,
      "httpStatus":200,
      "data":{
         "94":{
            "Offer":{
               "id":"94",
               "name":"Survey Junkie Panel - US, CA, AU (SOI)",
               "description":"<b>Description:</b> Start earning cash and rewards by doing surveys.<br><br>\r\n<b>Requirement:</b> Email Submit<br><br>\r\n<b>Country(ies):</b> US, CA, AU<br><br>\r\n<b>Media:</b> Display, Email<br><br>\r\n<b>Restrictions:</b> No incentives; no search; no pops; no brokering; no users under 18; no SnapChat<br><br>\r\n<b>Other:</b> New pubs need to pause at 300 leads and ask to be evaluated (if higher test cap is necessary, contact your affiliate manager to discuss). If traffic quality is good, Advertiser will lift lead cap as long as quality remains consistent. New partners should not start on weekends. Contact publishers@pantherainteractive.com when you reach your assigned lead cap.<br><br>",
               "require_approval":"0",
               "require_terms_and_conditions":0,
               "terms_and_conditions":null,
               "preview_url":"https://www.surveyjunkie.com/",
               "currency":null,
               "default_payout":"1.20000",
               "protocol":"server",
               "status":"active",
               "expiration_date":"2030-12-23 04:59:59",
               "payout_type":"cpa_flat",
               "percent_payout":"0.00",
               "featured":null,
               "conversion_cap":"0",
               "monthly_conversion_cap":"0",
               "payout_cap":"0.00",
               "monthly_payout_cap":"0.00",
               "allow_multiple_conversions":"0",
               "allow_website_links":"0",
               "allow_direct_links":"0",
               "show_custom_variables":"0",
               "session_hours":"24",
               "show_mail_list":"0",
               "dne_list_id":"0",
               "email_instructions":"0",
               "email_instructions_from":"",
               "email_instructions_subject":"",
               "enforce_secure_tracking_link":"1",
               "has_goals_enabled":"0",
               "default_goal_name":"",
               "modified":1622672025,
               "use_target_rules":"0",
               "use_payout_groups":"0",
               "link_platform":"",
               "is_expired":"0",
               "dne_download_url":null,
               "dne_unsubscribe_url":null,
               "dne_third_party_list":false,
               "approval_status":"approved"
            },
            "Country":{
               "US":{
                  "id":"840",
                  "code":"US",
                  "name":"United States",
                  "regions":[
                     
                  ]
               },
               "AU":{
                  "id":"36",
                  "code":"AU",
                  "name":"Australia",
                  "regions":[
                     
                  ]
               },
               "CA":{
                  "id":"124",
                  "code":"CA",
                  "name":"Canada",
                  "regions":[
                     
                  ]
               }
            }
         }
      }
   }
}

I have offer data:

@Getter @Setter
@JsonIgnoreProperties(ignoreUnknown = true)
public class OfferData {

  @JsonProperty("Offer")
  Offer offer;

  @JsonProperty("Country")
  Country country;

}

I'm already recovering de Offers correctly the problem is at the Country object.

The Country:

@Getter
@Setter
@JsonIgnoreProperties(ignoreUnknown = true)
public class Country {
  Map<String, CountryData> countryData;
}

The CountryData:

@Getter
@Setter
@JsonIgnoreProperties(ignoreUnknown = true)
public class CountryData {
  @JsonProperty("id")
  private String id;
  @JsonProperty("code")
  private String code;
  @JsonProperty("name")
  private String name;
  @JsonProperty("regions")
  List<Region> regions;
}

I'm getting this error:

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.client.RestClientException: Error while extracting response for type [class com.sample.surveydemo.model.dto.OfferMapper] and content type [application/json]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot deserialize value of type com.sample.surveydemo.model.dto.Country from Array value (token JsonToken.START_ARRAY ); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type com.sample.surveydemo.model.dto.Country from Array value (token JsonToken.START_ARRAY ) at [Source: (org.springframework.util.StreamUtils$NonClosingInputStream); line: 1, column: 92576] (through reference chain: com.sample.surveydemo.model.dto.OfferMapper["response"]->com.sample.surveydemo.model.dto.OfferResponse["data"]->java.util.LinkedHashMap["266"]->com.sample.surveydemo.model.dto.OfferData["Country"])] with root cause

Answer 1

Go to https://www.jsonschema2pojo.org/ . Copy and paste the JSON data and adjust the parameters (generate getters and setters, toString etc). Click on preview to see the converted JSON data in POJO format or you can download the zip file containing the POJO class.