storm-client/src/jvm/org/apache/storm/testing/TestWordCounter.java

/**
 * 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.storm.testing;

import static org.apache.storm.utils.Utils.tuple;

import java.util.HashMap;
import java.util.Map;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.BasicOutputCollector;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.topology.base.BaseBasicBolt;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Tuple;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class TestWordCounter extends BaseBasicBolt {
    public static Logger LOG = LoggerFactory.getLogger(TestWordCounter.class);

    Map<String, Integer> counts;

    @Override
    public void prepare(Map<String, Object> topoConf, TopologyContext context) {
        counts = new HashMap<String, Integer>();
    }

    protected String getTupleValue(Tuple t, int idx) {
        return (String) t.getValues().get(idx);
    }

    @Override
    public void execute(Tuple input, BasicOutputCollector collector) {
        String word = getTupleValue(input, 0);
        int count = 0;
        if (counts.containsKey(word)) {
            count = counts.get(word);
        }
        count++;
        counts.put(word, count);
        collector.emit(tuple(word, count));
    }

    @Override
    public void cleanup() {

    }

    @Override
    public void declareOutputFields(OutputFieldsDeclarer declarer) {
        declarer.declare(new Fields("word", "count"));
    }

}