Skip to content

Embed URL

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Real Collection Deserializer to parse arrays with GSON
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
public class CollectionDeserializer implements JsonDeserializer<Collection<?>> {
@Override
public Collection<?> deserialize(JsonElement json, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
Type realType = ((ParameterizedType)typeOfT).getActualTypeArguments()[0];
return parseAsArrayList(json, realType);
}
/**
* @param serializedData
* @param type
* @return
*/
@SuppressWarnings("unchecked")
public <T> ArrayList<T> parseAsArrayList(JsonElement json, T type) {
ArrayList<T> newArray = new ArrayList<T>();
Gson gson = new Gson();
JsonArray array= json.getAsJsonArray();
Iterator<JsonElement> iterator = array.iterator();
while(iterator.hasNext()){
JsonElement json2 = (JsonElement)iterator.next();
T object = (T) gson.fromJson(json2, (Class<?>)type);
newArray.add(object);
}
return newArray;
}
}
public class JSONParsingTest {
List<World> worlds;
@Test
public void grantThatDeserializerWorksAndParseObjectArrays(){
String worldAsString = "{\"worlds\": [" +
"{\"name\":\"name1\",\"id\":1}," +
"{\"name\":\"name2\",\"id\":2}," +
"{\"name\":\"name3\",\"id\":3}" +
"]}";
GsonBuilder builder = new GsonBuilder();
builder.registerTypeAdapter(Collection.class, new CollectionDeserializer());
Gson gson = builder.create();
Object decoded = gson.fromJson((String)worldAsString, JSONParsingTest.class);
assertNotNull(decoded);
assertTrue(JSONParsingTest.class.isInstance(decoded));
JSONParsingTest decodedObject = (JSONParsingTest)decoded;
assertEquals(3, decodedObject.worlds.size());
assertEquals((Long)2L, decodedObject.worlds.get(1).getId());
}
}
public class World {
private String name;
private Long id;
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}
@amrafu

Nice solution, I used it but I got error on: CollectionDeserializer.java
...
@Override
public Collection<?> deserialize(JsonElement json, Type typeOfT,
...

error:
The method deserialize(JsonElement, Type, JsonDeserializationContext) of type CollectionDeserializer must override a superclass method

Any idea?

Thanks in advance

@miere
Owner

Hi @amrafu
Sorry by the late, I missed up your answer notification.

Please, which version of GSon are you using?
I will try to simulate your problem to help you! ;)

@black-knight

Works great! Thanks! :-)

@corentinc

Thanks! Exactly what I'm looking for!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Something went wrong with that request. Please try again.