Converting json format using java bean

Question

I have a json string something similar

{"results":
[{"_type":"Position","_id":377078,"name":"Potsdam, Germany","type":"location","geo_position":{"latitude":52.39886,"longitude":13.06566}},
{"_type":"Position","_id":410978,"name":"Potsdam, USA","type":"location","geo_position":{"latitude":44.66978,"longitude":-74.98131}}]}

I am trying to convert to

    {"results":
 [{"_type":"Position","_id":377078,"name":"Potsdam, Germany","type":"location","latitude":52.39886,"longitude":13.06566}, 
{"_type":"Position","_id":410978,"name":"Potsdam, USA","type":"location","latitude":44.66978,"longitude":-74.98131}]}

I am converting to java and again converting back using But I am gettin null in data

  SourceJSON    data=new Gson().fromJson(jsonArray, SourceJSON.class);
           DestinationJSON destdata = new DestinationJSON();
           destdata.setLatitide(data.getGeoLocation().getLatitide());
           destdata.setLongitude(data.getGeoLocation().getLongitude());
           destdata.setId(data.getId());
           destdata.setType(data.getType());
           destdata.setName(data.getName());
           destdata.set_type(data.get_type());


           Gson gson = new Gson();
           String json = gson.toJson(destdata);

below are my beans

public class SourceJSON implements Serializable {
    private List<GEOLocation> geoLocations;
    private String  _type;
    private String id;
    private String name;
    private String type;


    public String get_type() {
        return _type;
    }
    public List<GEOLocation> getGeoLocations() {
        return geoLocations;
    }
    public void setGeoLocations(List<GEOLocation> geoLocations) {
        this.geoLocations = geoLocations;
    }
    public void set_type(String _type) {
        this._type = _type;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }



}

and

public class GEOLocation implements Serializable{
    private String latitide;
    private String longitude;
    public String getLatitide() {
        return latitide;
    }
    public void setLatitide(String latitide) {
        this.latitide = latitide;
    }
    public String getLongitude() {
        return longitude;
    }
    public void setLongitude(String longitude) {
        this.longitude = longitude;
    }


}

and destination java

public class DestinationJSON  implements Serializable {

    private String  _type;
    private String id;
    private String name;
    private String type;
    private String latitide;
    private String longitude;
    public String get_type() {
        return _type;
    }
    public void set_type(String _type) {
        this._type = _type;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public String getLatitide() {
        return latitide;
    }
    public void setLatitide(String latitide) {
        this.latitide = latitide;
    }
    public String getLongitude() {
        return longitude;
    }
    public void setLongitude(String longitude) {
        this.longitude = longitude;
    }
}

Do you need only to change the JSON or to store data into the classes? — giampaolo
– giampaolo, Commented Dec 6, 2013 at 21:06
I need to change the json this is one way i thought I can change but if you have any better way? — constantlearner
– constantlearner, Commented Dec 6, 2013 at 21:08

giampaolo · Accepted Answer · 2013-12-06 21:24:17Z

1

All you need is this. You can try this class in your IDE with a simple copy&paste.

package stackoverflow.questions;

import java.util.*;

import com.google.gson.Gson;

public class Q20433539{

   public static void main(String[] args){
         String json = "{\"results\":"+
         "[{\"_type\":\"Position\",\"_id\":377078,\"name\":\"Potsdam, Germany\",\"type\":\"location\",\"geo_position\":{\"latitude\":52.39886,\"longitude\":13.06566}},"+
         "{\"_type\":\"Position\",\"_id\":410978,\"name\":\"Potsdam, USA\",\"type\":\"location\",\"geo_position\":{\"latitude\":44.66978,\"longitude\":-74.98131}}]}";


   Gson gson = new Gson();
   Map m = gson.fromJson(json, Map.class);

   List<Map> innerList = (List<Map>) m.get("results");
   for(Map result: innerList){
      Map<String, Double> geo_position = (Map<String, Double>) result.get("geo_position");
      result.put("latitude", geo_position.get("latitude"));
      result.put("longitude", geo_position.get("longitude"));
      result.remove("geo_position");
   }
   System.out.println(gson.toJson(m));


   }


}

Of course, it works under the assumption that you always want to flat geo information.

Explanation: It's convenient to use POJO when working with Gson, but it's not the only way. Gson can also deseralize to Arrays/Maps if you do not specify the expected result. So I did, and then I manipulated the structure to unfold your data. After that, Gson can serialize Arrays/Maps structure again to your desidered JSON.

edited Dec 6, 2013 at 21:24

answered Dec 6, 2013 at 21:17

giampaolo

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1 Comment

giampaolo Over a year ago

Welcome. Btw, nice nickname. It reminds that we are here to learn from each other.

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