| /* |
| * 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 |
| * |
| * https://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 example; |
| |
| import java.io.IOException; |
| |
| import org.apache.avro.*; |
| import org.apache.avro.Schema.Type; |
| import org.apache.avro.mapred.*; |
| import org.apache.hadoop.conf.*; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.mapred.*; |
| import org.apache.hadoop.util.*; |
| |
| import example.avro.User; |
| |
| public class MapredColorCount extends Configured implements Tool { |
| |
| public static class ColorCountMapper extends AvroMapper<User, Pair<CharSequence, Integer>> { |
| @Override |
| public void map(User user, AvroCollector<Pair<CharSequence, Integer>> collector, Reporter reporter) |
| throws IOException { |
| CharSequence color = user.getFavoriteColor(); |
| // We need this check because the User.favorite_color field has type ["string", "null"] |
| if (color == null) { |
| color = "none"; |
| } |
| collector.collect(new Pair<CharSequence, Integer>(color, 1)); |
| } |
| } |
| |
| public static class ColorCountReducer extends AvroReducer<CharSequence, Integer, |
| Pair<CharSequence, Integer>> { |
| @Override |
| public void reduce(CharSequence key, Iterable<Integer> values, |
| AvroCollector<Pair<CharSequence, Integer>> collector, |
| Reporter reporter) |
| throws IOException { |
| int sum = 0; |
| for (Integer value : values) { |
| sum += value; |
| } |
| collector.collect(new Pair<CharSequence, Integer>(key, sum)); |
| } |
| } |
| |
| public int run(String[] args) throws Exception { |
| if (args.length != 2) { |
| System.err.println("Usage: MapredColorCount <input path> <output path>"); |
| return -1; |
| } |
| |
| JobConf conf = new JobConf(getConf(), MapredColorCount.class); |
| conf.setJobName("colorcount"); |
| |
| FileInputFormat.setInputPaths(conf, new Path(args[0])); |
| FileOutputFormat.setOutputPath(conf, new Path(args[1])); |
| |
| AvroJob.setMapperClass(conf, ColorCountMapper.class); |
| AvroJob.setReducerClass(conf, ColorCountReducer.class); |
| |
| // Note that AvroJob.setInputSchema and AvroJob.setOutputSchema set |
| // relevant config options such as input/output format, map output |
| // classes, and output key class. |
| AvroJob.setInputSchema(conf, User.getClassSchema()); |
| AvroJob.setOutputSchema(conf, Pair.getPairSchema(Schema.create(Type.STRING), |
| Schema.create(Type.INT))); |
| |
| JobClient.runJob(conf); |
| return 0; |
| } |
| |
| public static void main(String[] args) throws Exception { |
| int res = ToolRunner.run(new Configuration(), new MapredColorCount(), args); |
| System.exit(res); |
| } |
| } |