org.apache.twill.internal.json.TwillSpecificationCodec.java Source code

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Here is the source code for org.apache.twill.internal.json.TwillSpecificationCodec.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.twill.internal.json;

import com.google.common.reflect.TypeToken;
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 org.apache.twill.api.EventHandlerSpecification;
import org.apache.twill.api.Hosts;
import org.apache.twill.api.Racks;
import org.apache.twill.api.RuntimeSpecification;
import org.apache.twill.api.TwillSpecification;
import org.apache.twill.internal.DefaultEventHandlerSpecification;
import org.apache.twill.internal.DefaultTwillSpecification;

import java.lang.reflect.Type;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * An implementation of gson serializer/deserializer {@link org.apache.twill.api.TwillSpecification}.
 */
final class TwillSpecificationCodec
        implements JsonSerializer<TwillSpecification>, JsonDeserializer<TwillSpecification> {

    @Override
    public JsonElement serialize(TwillSpecification src, Type typeOfSrc, JsonSerializationContext context) {
        JsonObject json = new JsonObject();
        json.addProperty("name", src.getName());
        json.add("runnables",
                context.serialize(src.getRunnables(), new TypeToken<Map<String, RuntimeSpecification>>() {
                }.getType()));
        json.add("orders", context.serialize(src.getOrders(), new TypeToken<List<TwillSpecification.Order>>() {
        }.getType()));
        json.add("placementPolicies", context.serialize(src.getPlacementPolicies(),
                new TypeToken<List<TwillSpecification.PlacementPolicy>>() {
                }.getType()));
        EventHandlerSpecification eventHandler = src.getEventHandler();
        if (eventHandler != null) {
            json.add("handler", context.serialize(eventHandler, EventHandlerSpecification.class));
        }

        return json;
    }

    @Override
    public TwillSpecification deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
            throws JsonParseException {
        JsonObject jsonObj = json.getAsJsonObject();

        String name = jsonObj.get("name").getAsString();
        Map<String, RuntimeSpecification> runnables = context.deserialize(jsonObj.get("runnables"),
                new TypeToken<Map<String, RuntimeSpecification>>() {
                }.getType());
        List<TwillSpecification.Order> orders = context.deserialize(jsonObj.get("orders"),
                new TypeToken<List<TwillSpecification.Order>>() {
                }.getType());
        List<TwillSpecification.PlacementPolicy> placementPolicies = context.deserialize(
                jsonObj.get("placementPolicies"), new TypeToken<List<TwillSpecification.PlacementPolicy>>() {
                }.getType());

        JsonElement handler = jsonObj.get("handler");
        EventHandlerSpecification eventHandler = null;
        if (handler != null && !handler.isJsonNull()) {
            eventHandler = context.deserialize(handler, EventHandlerSpecification.class);
        }

        return new DefaultTwillSpecification(name, runnables, orders, placementPolicies, eventHandler);
    }

    static final class TwillSpecificationOrderCoder
            implements JsonSerializer<TwillSpecification.Order>, JsonDeserializer<TwillSpecification.Order> {

        @Override
        public JsonElement serialize(TwillSpecification.Order src, Type typeOfSrc,
                JsonSerializationContext context) {
            JsonObject json = new JsonObject();
            json.add("names", context.serialize(src.getNames(), new TypeToken<Set<String>>() {
            }.getType()));
            json.addProperty("type", src.getType().name());
            return json;
        }

        @Override
        public TwillSpecification.Order deserialize(JsonElement json, Type typeOfT,
                JsonDeserializationContext context) throws JsonParseException {
            JsonObject jsonObj = json.getAsJsonObject();

            Set<String> names = context.deserialize(jsonObj.get("names"), new TypeToken<Set<String>>() {
            }.getType());
            TwillSpecification.Order.Type type = TwillSpecification.Order.Type
                    .valueOf(jsonObj.get("type").getAsString());

            return new DefaultTwillSpecification.DefaultOrder(names, type);
        }
    }

    static final class TwillSpecificationPlacementPolicyCoder
            implements JsonSerializer<TwillSpecification.PlacementPolicy>,
            JsonDeserializer<TwillSpecification.PlacementPolicy> {

        @Override
        public JsonElement serialize(TwillSpecification.PlacementPolicy src, Type typeOfSrc,
                JsonSerializationContext context) {
            JsonObject json = new JsonObject();
            json.add("names", context.serialize(src.getNames(), new TypeToken<Set<String>>() {
            }.getType()));
            json.addProperty("type", src.getType().name());
            json.add("hosts", context.serialize(src.getHosts(), new TypeToken<Set<String>>() {
            }.getType()));
            json.add("racks", context.serialize(src.getRacks(), new TypeToken<Set<String>>() {
            }.getType()));
            return json;
        }

        @Override
        public TwillSpecification.PlacementPolicy deserialize(JsonElement json, Type typeOfT,
                JsonDeserializationContext context) throws JsonParseException {
            JsonObject jsonObj = json.getAsJsonObject();
            Set<String> names = context.deserialize(jsonObj.get("names"), new TypeToken<Set<String>>() {
            }.getType());
            TwillSpecification.PlacementPolicy.Type type = TwillSpecification.PlacementPolicy.Type
                    .valueOf(jsonObj.get("type").getAsString());
            Set<String> hosts = context.deserialize(jsonObj.get("hosts"), new TypeToken<Set<String>>() {
            }.getType());
            Set<String> racks = context.deserialize(jsonObj.get("racks"), new TypeToken<Set<String>>() {
            }.getType());
            return new DefaultTwillSpecification.DefaultPlacementPolicy(names, type, new Hosts(hosts),
                    new Racks(racks));
        }
    }

    static final class EventHandlerSpecificationCoder
            implements JsonSerializer<EventHandlerSpecification>, JsonDeserializer<EventHandlerSpecification> {

        @Override
        public JsonElement serialize(EventHandlerSpecification src, Type typeOfSrc,
                JsonSerializationContext context) {
            JsonObject json = new JsonObject();
            json.addProperty("classname", src.getClassName());
            json.add("configs", context.serialize(src.getConfigs(), new TypeToken<Map<String, String>>() {
            }.getType()));
            return json;
        }

        @Override
        public EventHandlerSpecification deserialize(JsonElement json, Type typeOfT,
                JsonDeserializationContext context) throws JsonParseException {
            JsonObject jsonObj = json.getAsJsonObject();
            String className = jsonObj.get("classname").getAsString();
            Map<String, String> configs = context.deserialize(jsonObj.get("configs"),
                    new TypeToken<Map<String, String>>() {
                    }.getType());

            return new DefaultEventHandlerSpecification(className, configs);
        }
    }
}