net.simonvt.cathode.jobqueue.JobSerializer.java Source code

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Here is the source code for net.simonvt.cathode.jobqueue.JobSerializer.java

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/*
 * Copyright (C) 2015 Simon Vig Therkildsen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.simonvt.cathode.jobqueue;

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 java.lang.reflect.Type;

public class JobSerializer implements JsonSerializer<Job>, JsonDeserializer<Job> {

    @Override
    public JsonElement serialize(Job src, Type typeOfSrc, JsonSerializationContext context) {
        final JsonObject member = new JsonObject();
        member.addProperty("type", src.getClass().getName());
        member.add("data", context.serialize(src, src.getClass()));
        return member;
    }

    @Override
    public Job deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
            throws JsonParseException {
        final JsonObject member = (JsonObject) json;
        final JsonElement typeString = get(member, "type");
        final JsonElement data = get(member, "data");
        final Type actualType = typeForName(typeString);
        return context.deserialize(data, actualType);
    }

    private Type typeForName(final JsonElement typeElem) {
        try {
            return Class.forName(typeElem.getAsString());
        } catch (ClassNotFoundException e) {
            throw new JsonParseException(e);
        }
    }

    private JsonElement get(final JsonObject wrapper, final String memberName) {
        final JsonElement elem = wrapper.get(memberName);
        if (elem == null) {
            throw new JsonParseException("no '" + memberName + "' member found in json file.");
        }
        return elem;
    }
}