com.kurtraschke.septa.gtfsrealtime.services.TransitViewService.java Source code

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Here is the source code for com.kurtraschke.septa.gtfsrealtime.services.TransitViewService.java

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/*
 * Copyright (C) 2014 Kurt Raschke <kurt@kurtraschke.com>
 *
 * 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.kurtraschke.septa.gtfsrealtime.services;

import com.google.common.collect.Iterables;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonNull;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.kurtraschke.septa.gtfsrealtime.model.Bus;

import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.BasicHttpClientConnectionManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Singleton;

@Singleton
public class TransitViewService {

    private Logger _log = LoggerFactory.getLogger(TransitViewService.class);
    private HttpClientConnectionManager _connectionManager;

    @PostConstruct
    public void start() {
        _connectionManager = new BasicHttpClientConnectionManager();
    }

    @PreDestroy
    public void stop() {
        _connectionManager.shutdown();
    }

    public Collection<Bus> getBuses() throws URISyntaxException, ClientProtocolException, IOException {
        URIBuilder b = new URIBuilder("http://www3.septa.org/hackathon/TransitViewAll/");

        CloseableHttpClient client = HttpClients.custom().setConnectionManager(_connectionManager).build();

        HttpGet httpget = new HttpGet(b.build());
        try (CloseableHttpResponse response = client.execute(httpget);
                InputStream responseInputStream = response.getEntity().getContent();
                Reader responseEntityReader = new InputStreamReader(responseInputStream)) {
            JsonParser parser = new JsonParser();

            JsonObject root = (JsonObject) parser.parse(responseEntityReader);

            JsonArray routes = (JsonArray) Iterables.getOnlyElement(root.entrySet()).getValue();

            List<Bus> allBuses = new ArrayList<>();

            for (JsonElement routeElement : routes) {
                JsonArray buses = ((JsonArray) (Iterables.getOnlyElement(((JsonObject) routeElement).entrySet())
                        .getValue()));

                for (JsonElement busElement : buses) {
                    JsonObject busObject = (JsonObject) busElement;

                    try {
                        allBuses.add(new Bus(busObject.get("lat").getAsDouble(), busObject.get("lng").getAsDouble(),
                                busObject.get("label").getAsString(), busObject.get("VehicleID").getAsString(),
                                busObject.get("BlockID").getAsString(), busObject.get("Direction").getAsString(),
                                (!(busObject.get("destination") instanceof JsonNull))
                                        ? busObject.get("destination").getAsString()
                                        : null,
                                busObject.get("Offset").getAsInt()));
                    } catch (Exception e) {
                        _log.warn("Exception processing bus JSON", e);
                        _log.warn(busObject.toString());
                    }
                }
            }
            return allBuses;
        }
    }

    public static void main(String... args) throws ClientProtocolException, URISyntaxException, IOException {
        TransitViewService tvs = new TransitViewService();
        tvs.start();
        for (Bus b : tvs.getBuses()) {
            System.out.println(b);
        }

        tvs.stop();
    }
}