Convert json structure to array using retrofit
I am having problems with Retrofit and ugly json object in Trakt.tv API:
{
"season": 1,
"episodes": {
"1": true,
"2": true,
"3": false,
"4": false,
"5": false,
"6": false,
"7": false
}
}
The "episodes" content is obviously dynamic and I would like to treat it as a simple boolean array, for example:
int season;
Boolean[] episodes;
How to do it?
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You can convert the JSON string to first Map<String,Object>
, then create the object you want .
example code:
public class EpisodesDetail {
private int season;
private Boolean[] episodes;
// getter & setter
}
...
BufferedReader reader = new BufferedReader(new FileReader(new File("json.txt")));
Type type = new TypeToken<Map<String, Object>>() {}.getType();
Map<String, Object> map = new Gson().fromJson(reader, type);
EpisodesDetail geometry = new EpisodesDetail();
geometry.setSeason(((Double) map.get("season")).intValue());
geometry.setEpisodes(((Map<String, Boolean>) map.get("episodes")).values().toArray(
new Boolean[] {}));
System.out.println(new GsonBuilder().setPrettyPrinting().create().toJson(geometry));
output:
{
"season": 1,
"episodes": [
true,
true,
false,
false,
false,
false,
false
]
}
There is another approach using Deserialiser GSON
example code:
class EpisodesDetailDeserializer implements JsonDeserializer<EpisodesDetail> {
@Override
public EpisodesDetail deserialize(final JsonElement json, final Type typeOfT,
final JsonDeserializationContext context) throws JsonParseException {
EpisodesDetail geometry = new EpisodesDetail();
JsonObject jsonObject = json.getAsJsonObject();
int season = jsonObject.get("season").getAsInt();
geometry.setSeason(season);
List<Boolean> episodes = new ArrayList<Boolean>();
Set<Entry<String, JsonElement>> set = jsonObject.get("episodes").getAsJsonObject()
.entrySet();
Iterator<Entry<String, JsonElement>> it = set.iterator();
while (it.hasNext()) {
episodes.add(it.next().getValue().getAsBoolean());
}
geometry.setEpisodes(episodes.toArray(new Boolean[] {}));
return geometry;
}
}
BufferedReader reader = new BufferedReader(new FileReader(new File("json.txt")));
EpisodesDetail episodesDetail = new GsonBuilder()
.registerTypeAdapter(EpisodesDetail.class, new EpisodesDetailDeserializer())
.create().fromJson(reader, EpisodesDetail.class);
System.out.println(new GsonBuilder().setPrettyPrinting().create().toJson(episodesDetail));
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When I use a library jackson
to parse this JSON, I use the class ObjectMapper
and DramaInfo
as follows.
package jackson;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import com.fasterxml.jackson.databind.ObjectMapper;
class DramaInfo {
int season;
List<Boolean> episodes;
public void setSeason(int season) {
this.season = season;
}
public int getSeason() {
return this.season;
}
public List<Boolean> getEpisodes() {
return new LinkedList<>( this.episodes );
}
public void setEpisodes(Map<String, Boolean> o) {
// used Java 1.8 Stream.
// just see http://docs.oracle.com/javase/tutorial/collections/streams/reduction.html
episodes = o.keySet().stream().map(e -> o.get(e)).collect(Collectors.toList());
}
public String toString() {
String ret = "season: " + this.season + "\n";
ret += this.episodes.toString();
return ret;
}
}
public class LoadJsonData {
public static void main(String[] args) {
String toConvert = "{\"season\": 1, \"episodes\": { \"1\": true, \"2\": true, \"3\": false, \"4\": false, \"5\": false, \"6\": false, \"7\": false } }";
ObjectMapper mapper = new ObjectMapper();
try {
DramaInfo info = mapper.readValue(toConvert, DramaInfo.class);
System.out.println(info);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
So this is a suggestion because I have never used Retrofit. If you want to use Retrofit in the following way, how about trying the class DramaInfo
shown above?
public interface DramaService {
@GET("/dramas/{drama}/info")
DramaInfo listRepos(@Path("drama") String drama);
}
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