org.apache.avro.mapred.TestWordCountGeneric.java Source code

Introduction

Here is the source code for org.apache.avro.mapred.TestWordCountGeneric.java

Source

/**
 * 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.avro.mapred;

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;

import org.apache.avro.Schema;
import org.apache.avro.util.Utf8;
import org.apache.avro.generic.GenericRecord;
import org.apache.avro.generic.GenericData;
import org.junit.Test;

public class TestWordCountGeneric {

    private static GenericRecord newWordCount(String word, int count) {
        GenericRecord value = new GenericData.Record(WordCount.SCHEMA$);
        value.put("word", new Utf8(word));
        value.put("count", count);
        return value;
    }

    public static class MapImpl extends AvroMapper<Utf8, GenericRecord> {
        public void map(Utf8 text) throws IOException {
            StringTokenizer tokens = new StringTokenizer(text.toString());
            while (tokens.hasMoreTokens())
                collect(newWordCount(tokens.nextToken(), 1));
        }
    }

    public static class ReduceImpl extends AvroReducer<GenericRecord, GenericRecord> {

        private GenericRecord previous;

        public void reduce(GenericRecord current) throws IOException {
            if (current.equals(previous)) {
                previous.put("count", ((Integer) previous.get("count")) + (Integer) current.get("count"));
            } else {
                if (previous != null)
                    collect(previous);
                previous = newWordCount(current.get("word").toString(), (Integer) current.get("count"));
            }
        }

        public void close() throws IOException {
            if (previous != null)
                collect(previous);
        }

    }

    @Test
    @SuppressWarnings("deprecation")
    public void testJob() throws Exception {
        String dir = System.getProperty("test.dir", ".") + "/mapred";
        Path outputPath = new Path(dir + "/out");
        JobConf job = new JobConf();
        try {
            WordCountUtil.writeLinesFile();

            job.setJobName("wordcount");

            AvroJob.setInputGeneric(job, Schema.create(Schema.Type.STRING));
            AvroJob.setOutputGeneric(job, WordCount.SCHEMA$);

            job.setMapperClass(MapImpl.class);
            job.setCombinerClass(ReduceImpl.class);
            job.setReducerClass(ReduceImpl.class);

            FileInputFormat.setInputPaths(job, new Path(dir + "/in"));
            FileOutputFormat.setOutputPath(job, outputPath);
            FileOutputFormat.setCompressOutput(job, true);

            JobClient.runJob(job);

            WordCountUtil.validateCountsFile();
        } finally {
            outputPath.getFileSystem(job).delete(outputPath);
        }
    }

}