nl.utwente.bigdata.bolts.WorldCupJsonToDataBolt.java Source code

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Here is the source code for nl.utwente.bigdata.bolts.WorldCupJsonToDataBolt.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 nl.utwente.bigdata.bolts;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

import backtype.storm.task.TopologyContext;
import backtype.storm.topology.BasicOutputCollector;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.topology.base.BaseBasicBolt;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Values;

/**
 * Extracts world cup data from World Cup JSON 
 * and emits the referee name, home team, out team and date of the match
 * 
 * @TODO: implement
 * 
 * @author Djuri Baars
 * @author Martijn Hensema
 * @package Assignment7 
 */
public class WorldCupJsonToDataBolt extends BaseBasicBolt {
    private transient JSONParser parser;

    @Override
    public void prepare(Map stormConf, TopologyContext context) {
        parser = new JSONParser();
    }

    @Override
    public void execute(Tuple tuple, BasicOutputCollector collector) {
        try {
            JSONObject game = (JSONObject) parser.parse(tuple.getString(0));

            JSONArray officials = (JSONArray) game.get("officials");
            JSONObject home = (JSONObject) game.get("home");
            JSONObject away = (JSONObject) game.get("away");

            String referee_name = "";
            String home_name = (String) home.get("name");
            String away_name = (String) away.get("name");

            SimpleDateFormat formatter = new SimpleDateFormat("dd MMM yyyy - k:mm");
            Date matchTime = new Date();
            matchTime = formatter.parse((String) game.get("time"));
            Iterator i = officials.iterator();

            while (i.hasNext()) {
                JSONObject official = (JSONObject) i.next();
                if (official.get("role").equals("Referee")) {
                    referee_name = (String) official.get("name");
                }
            }
            //System.out.println(referee_name);
            collector.emit(new Values(referee_name, home_name, away_name, matchTime));
        } catch (ClassCastException e) {
            System.out.println("ClassCass");
            e.printStackTrace();
            return; // do nothing (we might log this)
        } catch (org.json.simple.parser.ParseException e) {
            System.out.println("ParseException");
            e.printStackTrace();
            return; // do nothing 
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer declarer) {
        declarer.declare(new Fields("referee_name", "home", "out", "time"));
    }

}