praktikum-holons/src/holeg/serialize/CategoryAdapter.java

package holeg.serialize;

import com.google.gson.*;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import holeg.model.AbstractCanvasObject;
import holeg.model.Edge;
import holeg.model.HolonObject;
import holeg.model.HolonSwitch;
import holeg.ui.view.category.Category;

import java.io.IOException;
import java.lang.reflect.Type;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;
import java.util.stream.Collectors;

public class CategoryAdapter implements JsonSerializer<Category>, JsonDeserializer<Category> {
    public static final Gson Gson = initGson();
    public static final Type CategorySet = new TypeToken<Set<Category>>(){}.getType();
    private static final Type HolonObjectList = new TypeToken<List<HolonObject>>(){}.getType();
    private static final Type HolonSwitchList = new TypeToken<List<HolonSwitch>>(){}.getType();


    private static Gson initGson() {
        GsonBuilder gson = new GsonBuilder();
        gson.registerTypeAdapter(Category.class, new CategoryAdapter());
        gson.registerTypeAdapterFactory(new PostDeserializeEnabler());
        gson.serializeNulls();
        return gson.create();
    }

    @Override
    public JsonElement serialize(Category src, Type typeOfSrc, JsonSerializationContext context) {
        JsonObject object = new JsonObject();
        object.addProperty("name", src.getName());

        Map<Class<?>, List<AbstractCanvasObject>> map =
                src.getObjects().stream()
                        .collect(Collectors.groupingBy(Object::getClass));
        object.add("objects", context.serialize(map.get(HolonObject.class), HolonObjectList));
        object.add("switches", context.serialize(map.get(HolonSwitch.class), HolonSwitchList));
        return object;
    }

    @Override
    public Category deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
        JsonObject object = json.getAsJsonObject();
        Category cat = new Category(object.get("name").getAsString());
        if(object.has("objects") && !object.get("objects").isJsonNull()){
            cat.getObjects().addAll(context.deserialize(object.getAsJsonArray("objects"), HolonObjectList));
        }
        if(object.has("switches") && !object.get("switches").isJsonNull()){
            cat.getObjects().addAll(context.deserialize(object.getAsJsonArray("switches"), HolonSwitchList));
        }
        return cat;
    }
}