com.google.iosched.server.input.fetcher.CloudStorageRemoteFilesEntityFetcher.java Source code

Introduction

Here is the source code for com.google.iosched.server.input.fetcher.CloudStorageRemoteFilesEntityFetcher.java

Source

/*
 * Copyright 2014 Google Inc. All rights reserved.
 *
 * 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.iosched.server.input.fetcher;

import com.google.appengine.api.utils.SystemProperty;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.iosched.Config;
import com.google.iosched.input.fetcher.EntityFetcher;
import com.google.iosched.input.fetcher.RemoteJsonHelper;
import com.google.iosched.server.cloudstorage.CloudFileManager;

import java.io.IOException;
import java.util.Arrays;
import java.util.Map;
import java.util.Map.Entry;
import java.util.logging.Logger;

/**
 * EntityFetcher that fetches entities from a set of files stored in CloudStorage.
 */
public class CloudStorageRemoteFilesEntityFetcher implements EntityFetcher {

    private static final Logger LOGGER = Logger.getLogger(CloudStorageRemoteFilesEntityFetcher.class.getName());

    private CloudFileManager fileManager;
    private String[] filenames;
    private JsonObject object;

    public CloudStorageRemoteFilesEntityFetcher(String... filenames) {
        this.fileManager = new CloudFileManager();
        this.filenames = filenames;
    }

    @Override
    public JsonElement fetch(Enum<?> entityType, Map<String, String> params) throws IOException {
        // On the first call, read all the files
        if (object == null) {
            object = new JsonObject();
            for (String filename : filenames) {
                JsonObject obj = fileManager.readFileAsJsonObject(filename);
                if (obj == null
                        && SystemProperty.environment.value() == SystemProperty.Environment.Value.Development) {
                    // In the development server, cloud storage files cannot be directly accessed.
                    obj = RemoteJsonHelper.fetchJsonFromPublicURL(Config.CLOUD_STORAGE_BASE_URL + filename);
                }
                if (obj == null) {
                    LOGGER.warning("Could not find file " + filename);
                } else {
                    for (Entry<String, JsonElement> entry : obj.entrySet()) {
                        object.add(entry.getKey(), entry.getValue());
                    }
                }
            }
        }
        return object.get(entityType.name());
    }

    @Override
    public String toString() {
        return "CloudStorageEntityFetcher(filenames=" + Arrays.toString(filenames) + ")";
    }
}