Question

我正在解析来自json restful webservice的json数据，并给出了这个结果

{
  "RestResponse" : {
    "result" : {
      "countryIso2" : "US",
      "stateAbbr" : "CA",
      "postal" : "94043",
      "continent" : "North America",
      "state" : "California",
      "longitude" : "-122.0574",
      "latitude" : "37.4192",
      "ds" : "II",
      "network" : "AS15169 Google Inc.",
      "city" : "Mountain View",
      "country" : "United States",
      "ip" : "172.217.3.14"
    }
  }
}

所以我的pojos是这样的：

public class TestIpAdress {
@SerializedName("RestResponse")
private RestResponse restResponse;

public RestResponse getRestResponse() {
    return restResponse;
}

public void setRestResponse(RestResponse restResponse) {
    this.restResponse = restResponse;
}
}

public class RestResponse {
    @SerializedName("result")
    private Result result;

    public Result getResult() {
        return result;
    }

    public void setResult(Result result) {
        this.result = result;
    }
}

public class Result {
    @SerializedName("countryIso2")
    private String countryIso2;
    @SerializedName("postal")
    private String postal;
    @SerializedName("continent")
    private String continent;
    @SerializedName("state")
    private String state;
    @SerializedName("longitude")
    private Double longitude;
    @SerializedName("latitude")
    private Double latitude;
    @SerializedName("ds")
    private String ds;
    @SerializedName("ip")
    private String ip;
    @SerializedName("city")
    private String city;
    @SerializedName("country")
    private String country;

    public String getCountryIso2() {
        return countryIso2;
    }

    public void setCountryIso2(String countryIso2) {
        this.countryIso2 = countryIso2;
    }

    public String getPostal() {
        return postal;
    }

    public void setPostal(String postal) {
        this.postal = postal;
    }

    public String getContinent() {
        return continent;
    }

    public void setContinent(String continent) {
        this.continent = continent;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public Double getLongitude() {
        return longitude;
    }

    public void setLongitude(Double longitude) {
        this.longitude = longitude;
    }

    public Double getLatitude() {
        return latitude;
    }

    public void setLatitude(Double latitude) {
        this.latitude = latitude;
    }

    public String getDs() {
        return ds;
    }

    public void setDs(String ds) {
        this.ds = ds;
    }

    public String getIp() {
        return ip;
    }

    public void setIp(String ip) {
        this.ip = ip;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }
}

在Android应用中，我使用以下内容来检索和解析Web服务输出：

    StrictMode.ThreadPolicy policy = new 
    StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
    String link = "http://geo.groupkt.com/ip/172.217.3.14/json";
    URL url = new URL(link);

    HttpURLConnection urlConnection = 
    (HttpURLConnection)url.openConnection();

    InputStream inputStream = urlConnection.getInputStream();

    InputStreamReader reader = new InputStreamReader(inputStream);

    Gson gson = new Gson();
    RestResponse restResponse = gson.fromJson(reader, new 
        TypeToken<RestResponse>(){}.getType());

    Result myPosition = restResponse.getResult();
    editText.setText("My city :\n" + myPosition.getCity());

但是我总是在“myPosition”对象中得到一个空值，有什么建议吗？

Answer 1

您的json只有一个名为RestResponse的属性，您需要使用具有此属性的类，例如TestIpAdress。

TestIpAdress response = gson.fromJson(reader, TestIpAdress.class);
RestResponse restResponse = response.getRestResponse();

gson从restful webservice返回null值

1 个答案: