ch.njol.skript.update.ReleaseManifest.java Source code

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Here is the source code for ch.njol.skript.update.ReleaseManifest.java

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/**
 *   This file is part of Skript.
 *
 *  Skript 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  Skript 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 Skript.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Copyright 2011-2017 Peter Gttinger and contributors
 */
package ch.njol.skript.update;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Type;

import org.eclipse.jdt.annotation.Nullable;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;
import com.google.gson.TypeAdapter;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;

/**
 * Describes a Skript release.
 */
public class ReleaseManifest {

    /**
     * Loads a release manifest from JSON.
     * @param json Release manifest.
     * @return A release manifest.
     * @throws JsonParseException If the given JSON was not valid.
     */
    @SuppressWarnings("null")
    public static ReleaseManifest load(String json) throws JsonParseException {
        return new GsonBuilder().registerTypeAdapter(Class.class, new ClassSerializer()).create().fromJson(json,
                ReleaseManifest.class);
    }

    /**
     * Release id, for example "2.3".
     */
    public final String id;

    /**
     * When the release was published.
     */
    public final String date;

    /**
     * Flavor of the release. For example "github" or "custom".
     */
    public final String flavor;

    /**
     * Type of update checker to use for this release.
     */
    public final Class<? extends UpdateChecker> updateCheckerType;

    /**
     * Source where updates for this release can be found,
     * if there are updates.
     */
    public final String updateSource;

    /**
     * Source for downloads. If null, update checker will figure out it.
     */
    @Nullable
    public final String downloadSource;

    public ReleaseManifest(String id, String date, String flavor, Class<? extends UpdateChecker> updateCheckerType,
            String updateSource, @Nullable String downloadSource) {
        this.id = id;
        this.date = date;
        this.flavor = flavor;
        this.updateCheckerType = updateCheckerType;
        this.updateSource = updateSource;
        this.downloadSource = downloadSource;
    }

    /**
     * Serializes class to JSON and back.
     */
    static class ClassSerializer implements JsonSerializer<Class<?>>, JsonDeserializer<Class<?>> {

        @Override
        public @Nullable Class<?> deserialize(@Nullable JsonElement json, @Nullable Type typeOfT,
                @Nullable JsonDeserializationContext context) throws JsonParseException {
            try {
                assert json != null;
                return Class.forName(json.getAsJsonPrimitive().getAsString());
            } catch (ClassNotFoundException e) {
                throw new JsonParseException("class not found");
            }
        }

        @Override
        public JsonElement serialize(@Nullable Class<?> src, @Nullable Type typeOfSrc,
                @Nullable JsonSerializationContext context) {
            assert src != null;
            return new JsonPrimitive(src.getName());
        }

    }

    /**
     * Creates an instance of the updater used by this type.
     * @return New updater instance.
     */
    @SuppressWarnings("null")
    public UpdateChecker createUpdateChecker() {
        try {
            return updateCheckerType.getConstructor().newInstance();
        } catch (InstantiationException | IllegalAccessException | IllegalArgumentException
                | InvocationTargetException | NoSuchMethodException | SecurityException e) {
            throw new IllegalStateException("updater class cannot be created", e);
        }
    }
}