com.google.wave.splash.data.serialize.JsonSerializer.java Source code

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Here is the source code for com.google.wave.splash.data.serialize.JsonSerializer.java

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/**
 * Copyright 2010 Google Inc.
 *
 * 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 com.google.wave.splash.data.serialize;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.reflect.TypeToken;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.google.wave.splash.web.stats.Timed;
import com.google.wave.api.Blip;
import com.google.wave.api.BlipData;
import com.google.wave.api.BlipThread;
import com.google.wave.api.FetchProfilesResult;
import com.google.wave.api.OperationQueue;
import com.google.wave.api.ParticipantProfile;
import com.google.wave.api.SearchResult;
import com.google.wave.api.Wavelet;
import com.google.wave.api.SearchResult.Digest;
import com.google.wave.api.impl.WaveletData;

import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Logger;

/**
 * Monolithic deserializer for various rpc calls.
 *
 * @author David Byttow
 */
@Singleton
public class JsonSerializer {
    private static final Logger LOG = Logger.getLogger(JsonSerializer.class.getName());
    private static final Type DIGEST_LIST_TYPE = new TypeToken<List<SearchResult.Digest>>() {
    }.getType();

    private final Gson gson;
    private final JsonParser parser;

    @Inject
    public JsonSerializer(Gson gson, JsonParser parser) {
        this.gson = gson;
        this.parser = parser;
    }

    /**
     * Parses a string of json from a wave.robot.search rpc into a search result
     * with a set of digests.
     *
     * @param query the query used to get the search results.
     * @param json the json to parse.
     * @return a result object, which may not contain results.
     */
    public SearchResult parseSearchResult(String query, String json) {
        JsonObject dataObject = getDataObject(json);
        SearchResult result = new SearchResult(query);
        if (dataObject == null) {
            LOG.warning("Search returned empty result: " + query);
            return result;
        }
        if (dataObject != null) {
            JsonArray digestElements = dataObject.getAsJsonObject("searchResults").getAsJsonArray("digests");
            List<Digest> digests = gson.fromJson(digestElements, DIGEST_LIST_TYPE);
            for (Digest digest : digests) {
                result.addDigest(digest);
            }
        }
        return result;
    }

    /**
     * Parses a string of json from a wave.robot.fetchWave into a result.
     *
     * @param json the json to parse.
     * @return the result object, which may not contain a wavelet.
     */
    @Timed
    public FetchWaveletResult parseFetchWaveletResult(String json) {
        JsonObject dataObject = getDataObject(json);
        if (dataObject == null || !dataObject.has("waveletData")) {
            LOG.warning("Fetch returned empty result.");
            return FetchWaveletResult.emptyResult();
        }

        JsonObject waveletDataJson = dataObject.getAsJsonObject("waveletData");
        OperationQueue operationQueue = new OperationQueue();
        WaveletData waveletData = gson.fromJson(waveletDataJson, WaveletData.class);

        Map<String, Blip> blips = Maps.newHashMap();
        HashMap<String, BlipThread> threads = Maps.newHashMap();
        Wavelet wavelet = Wavelet.deserialize(operationQueue, blips, threads, waveletData);

        JsonObject threadMap = dataObject.getAsJsonObject("threads");
        if (null != threadMap) {
            for (Map.Entry<String, JsonElement> entries : threadMap.entrySet()) {
                JsonObject threadElement = entries.getValue().getAsJsonObject();
                int location = threadElement.get("location").getAsInt();

                List<String> blipIds = Lists.newArrayList();
                for (JsonElement blipId : threadElement.get("blipIds").getAsJsonArray()) {
                    blipIds.add(blipId.getAsString());
                }

                BlipThread thread = new BlipThread(entries.getKey(), location, blipIds, blips);
                threads.put(thread.getId(), thread);
            }
        }

        JsonObject blipMap = dataObject.getAsJsonObject("blips");
        for (Map.Entry<String, JsonElement> entries : blipMap.entrySet()) {
            BlipData blipData = gson.fromJson(entries.getValue(), BlipData.class);
            Blip blip = Blip.deserialize(operationQueue, wavelet, blipData);
            blips.put(blipData.getBlipId(), blip);
        }

        return new FetchWaveletResult(wavelet);
    }

    @Timed
    public FetchProfilesResult parseFetchProfilesResult(String json) {
        JsonObject dataObject = getDataObject(json);
        if (dataObject == null || !dataObject.has("fetchProfilesResult")) {
            LOG.warning("Fetch profiles returned empty result.");
            return new FetchProfilesResult(ImmutableList.<ParticipantProfile>of());
        }

        // TODO: Parse the result when this service works.
        return new FetchProfilesResult(ImmutableList.<ParticipantProfile>of());
    }

    private JsonObject getDataObject(String json) {
        if (json == null) {
            return null;
        }
        JsonArray array = parser.parse(json).getAsJsonArray();
        if (array.size() == 0) {
            return null;
        }
        return array.get(0).getAsJsonObject().getAsJsonObject("data");
    }
}