de.bwravencl.controllerbuddy.json.ActionTypeAdapter.java Source code

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Here is the source code for de.bwravencl.controllerbuddy.json.ActionTypeAdapter.java

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/* Copyright (C) 2019  Matteo Hausner
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

package de.bwravencl.controllerbuddy.json;

import java.lang.System.Logger;
import java.lang.reflect.Type;
import java.util.HashSet;
import java.util.Set;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;

import de.bwravencl.controllerbuddy.input.action.IAction;
import de.bwravencl.controllerbuddy.input.action.NullAction;

public class ActionTypeAdapter implements JsonSerializer<IAction<?>>, JsonDeserializer<IAction<?>> {

    private static final Logger log = System.getLogger(ActionTypeAdapter.class.getName());

    private static final String PROPERTY_TYPE = "type";
    private static final String PROPERTY_DATA = "data";

    private static JsonElement get(final JsonObject wrapper, final String memberName) {
        final var jsonElement = wrapper.get(memberName);
        if (jsonElement == null)
            throw new JsonParseException(
                    "No member '" + memberName + "' found in what was expected to be an interface wrapper");

        return jsonElement;
    }

    private final Set<String> unknownActionClasses = new HashSet<>();

    @Override
    public IAction<?> deserialize(final JsonElement json, final Type typeOfT,
            final JsonDeserializationContext context) throws JsonParseException {
        final var wrapper = json.getAsJsonObject();
        final var typeName = get(wrapper, PROPERTY_TYPE);
        final var typeNameString = typeName.getAsString();
        final var data = get(wrapper, PROPERTY_DATA);

        try {
            final var actualType = Class.forName(typeNameString);
            return context.deserialize(data, actualType);
        } catch (final ClassNotFoundException e) {
            if (typeOfT == IAction.class) {
                log.log(Logger.Level.WARNING, "Action class '" + typeNameString + "' not found, substituting with '"
                        + NullAction.class.getSimpleName() + "'");
                unknownActionClasses.add(typeNameString);

                return new NullAction();
            }

            throw new JsonParseException(e);
        }
    }

    public Set<String> getUnknownActionClasses() {
        return unknownActionClasses;
    }

    @Override
    public JsonElement serialize(final IAction<?> src, final Type typeOfSrc,
            final JsonSerializationContext context) {
        final var wrapper = new JsonObject();
        wrapper.addProperty(PROPERTY_TYPE, src.getClass().getName());
        wrapper.add(PROPERTY_DATA, context.serialize(src));

        return wrapper;
    }

}