Retrofit returns LinkedTreeMap instead of JSON

Question

I am using Retrofit 2.0 to read data from a web service which returns a json text, but in following code response is LinkedTreeMap and I can't convert it to json:

My interface

public interface GeoAPIInterface {
    String ENDPOINT = "http://www.geoplugin.net/";

    @GET("json.gp")
    Call<Object> getIP(@Query("ip") String ip);
}

Now I read data from site :

Retrofit retrofit = new Retrofit.Builder()
         .baseUrl(GeoAPIInterface.ENDPOINT)
         .addConverterFactory(GsonConverterFactory.create())
         .build();
GeoAPIInterface inBankAPI = retrofit.create(GeoAPIInterface.class);
Call<Object> call=inBankAPI.getIP("8.8.8.8");
call.enqueue(new Callback<Object>() {
    @Override
    public void onResponse(Response<Object> response, Retrofit retrofit) {
        Log.d("App","");
    }

    @Override
        public void onFailure(Throwable t) {
            Log.d("App","error!");
    }
});

url formed is http://www.geoplugin.net/json.gp?ip=8.8.8.8 json response is

{
  "geoplugin_request":"8.8.8.8",
  "geoplugin_status":200,
  "geoplugin_credit":"Some of the returned data includes GeoLite data created by MaxMind, available from <a href=\\'http:\/\/www.maxmind.com\\'>http:\/\/www.maxmind.com<\/a>.",
  "geoplugin_city":"Mountain View",
  "geoplugin_region":"CA",
  "geoplugin_areaCode":"650",
  "geoplugin_dmaCode":"807",
  "geoplugin_countryCode":"US",
  "geoplugin_countryName":"United States",
  "geoplugin_continentCode":"NA",
  "geoplugin_latitude":"37.386002",
  "geoplugin_longitude":"-122.083801",
  "geoplugin_regionCode":"CA",
  "geoplugin_regionName":"California",
  "geoplugin_currencyCode":"USD",
  "geoplugin_currencySymbol":"&#36;",
  "geoplugin_currencySymbol_UTF8":"$",
  "geoplugin_currencyConverter":1
}

Answer 1

Replace your Response<Object> with Response<GeoData> where

public class GeoData{
    private String geoplugin_regionCode;
    private String geoplugin_city;
    private String geoplugin_credit;
    private String geoplugin_currencyConverter;
    private String geoplugin_currencyCode;
    private String geoplugin_region;
    private String geoplugin_currencySymbol;
    private String geoplugin_regionName;
    private String geoplugin_countryName;
    private String geoplugin_currencySymbol_UTF8;
    private String geoplugin_areaCode;
    private String geoplugin_dmaCode;
    private String geoplugin_continentCode;
    private String geoplugin_request;
    private String geoplugin_latitude;
    private String geoplugin_longitude;
    private String geoplugin_countryCode;
    private String geoplugin_status;

    public String getGeoplugin_regionCode () {
        return geoplugin_regionCode;
    }
    public void setGeoplugin_regionCode (String geoplugin_regionCode) {
        this.geoplugin_regionCode = geoplugin_regionCode;
    }
    public String getGeoplugin_city () {
        return geoplugin_city;
    }
    public void setGeoplugin_city (String geoplugin_city) {
        this.geoplugin_city = geoplugin_city;
    }
    public String getGeoplugin_credit () {
        return geoplugin_credit;
    }
    public void setGeoplugin_credit (String geoplugin_credit) {
        this.geoplugin_credit = geoplugin_credit;
    }
    public String getGeoplugin_currencyConverter () {
        return geoplugin_currencyConverter;
    }
    public void setGeoplugin_currencyConverter (String geoplugin_currencyConverter) {
        this.geoplugin_currencyConverter = geoplugin_currencyConverter;
    }
    public String getGeoplugin_currencyCode () {
        return geoplugin_currencyCode;
    }
    public void setGeoplugin_currencyCode (String geoplugin_currencyCode) {
        this.geoplugin_currencyCode = geoplugin_currencyCode;
    }
    public String getGeoplugin_region () {
        return geoplugin_region;
    }
    public void setGeoplugin_region (String geoplugin_region) {
        this.geoplugin_region = geoplugin_region;
    }
    public String getGeoplugin_currencySymbol () {
        return geoplugin_currencySymbol;
    }
    public void setGeoplugin_currencySymbol (String geoplugin_currencySymbol) {
        this.geoplugin_currencySymbol = geoplugin_currencySymbol;
    }
    public String getGeoplugin_regionName () {
        return geoplugin_regionName;
    }
    public void setGeoplugin_regionName (String geoplugin_regionName) {
        this.geoplugin_regionName = geoplugin_regionName;
    }
    public String getGeoplugin_countryName () {
        return geoplugin_countryName;
    }
    public void setGeoplugin_countryName (String geoplugin_countryName) {
        this.geoplugin_countryName = geoplugin_countryName;
    }
    public String getGeoplugin_currencySymbol_UTF8 () {
        return geoplugin_currencySymbol_UTF8;
    }
    public void setGeoplugin_currencySymbol_UTF8 (String geoplugin_currencySymbol_UTF8) {
        this.geoplugin_currencySymbol_UTF8 = geoplugin_currencySymbol_UTF8;
    }
    public String getGeoplugin_areaCode () {
        return geoplugin_areaCode;
    }
    public void setGeoplugin_areaCode (String geoplugin_areaCode) {
        this.geoplugin_areaCode = geoplugin_areaCode;
    }
    public String getGeoplugin_dmaCode () {
        return geoplugin_dmaCode;
    }
    public void setGeoplugin_dmaCode (String geoplugin_dmaCode) {
        this.geoplugin_dmaCode = geoplugin_dmaCode;
    }
    public String getGeoplugin_continentCode () {
        return geoplugin_continentCode;
    }
    public void setGeoplugin_continentCode (String geoplugin_continentCode) {
        this.geoplugin_continentCode = geoplugin_continentCode;
    }
    public String getGeoplugin_request () {
        return geoplugin_request;
    }
    public void setGeoplugin_request (String geoplugin_request) {
        this.geoplugin_request = geoplugin_request;
    }
    public String getGeoplugin_latitude () {
        return geoplugin_latitude;
    }
    public void setGeoplugin_latitude (String geoplugin_latitude) {
        this.geoplugin_latitude = geoplugin_latitude;
    }
    public String getGeoplugin_longitude () {
        return geoplugin_longitude;
    }
    public void setGeoplugin_longitude (String geoplugin_longitude) {
        this.geoplugin_longitude = geoplugin_longitude;
    }
    public String getGeoplugin_countryCode () {
        return geoplugin_countryCode;
    }
    public void setGeoplugin_countryCode (String geoplugin_countryCode) {
        this.geoplugin_countryCode = geoplugin_countryCode;
    }
    public String getGeoplugin_status () {
        return geoplugin_status;
    }
    public void setGeoplugin_status (String geoplugin_status) {
        this.geoplugin_status = geoplugin_status;
    }
}

and you already has all parameters in this object, you do not need convert and parse JSON. Here you could get object from your JSON.

Answer 2

I recommend you to use Jackson for creating object.

Instead of

Call<Object> getIP(@Query("ip") String ip);

you will have

Call<myObject> getIP(@Query("ip") String ip);

Where myObject will be your custom object with all fields annotated with proper name in @JSONProperty like here. It's very cool stuff and easy to use.