| /* |
| * 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.Schema; |
| import org.apache.avro.mapred.AvroKey; |
| import org.apache.avro.mapred.AvroValue; |
| import org.apache.avro.mapreduce.AvroJob; |
| import org.apache.avro.mapreduce.AvroKeyInputFormat; |
| import org.apache.avro.mapreduce.AvroKeyValueOutputFormat; |
| import org.apache.hadoop.conf.Configured; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.IntWritable; |
| import org.apache.hadoop.io.NullWritable; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapreduce.Job; |
| import org.apache.hadoop.mapreduce.Mapper; |
| import org.apache.hadoop.mapreduce.Reducer; |
| import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; |
| import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; |
| import org.apache.hadoop.util.Tool; |
| import org.apache.hadoop.util.ToolRunner; |
| |
| import example.avro.User; |
| |
| public class MapReduceColorCount extends Configured implements Tool { |
| |
| public static class ColorCountMapper extends |
| Mapper<AvroKey<User>, NullWritable, Text, IntWritable> { |
| |
| @Override |
| public void map(AvroKey<User> key, NullWritable value, Context context) |
| throws IOException, InterruptedException { |
| |
| CharSequence color = key.datum().getFavoriteColor(); |
| if (color == null) { |
| color = "none"; |
| } |
| context.write(new Text(color.toString()), new IntWritable(1)); |
| } |
| } |
| |
| public static class ColorCountReducer extends |
| Reducer<Text, IntWritable, AvroKey<CharSequence>, AvroValue<Integer>> { |
| |
| @Override |
| public void reduce(Text key, Iterable<IntWritable> values, |
| Context context) throws IOException, InterruptedException { |
| |
| int sum = 0; |
| for (IntWritable value : values) { |
| sum += value.get(); |
| } |
| context.write(new AvroKey<CharSequence>(key.toString()), new AvroValue<Integer>(sum)); |
| } |
| } |
| |
| public int run(String[] args) throws Exception { |
| if (args.length != 2) { |
| System.err.println("Usage: MapReduceColorCount <input path> <output path>"); |
| return -1; |
| } |
| |
| Job job = new Job(getConf()); |
| job.setJarByClass(MapReduceColorCount.class); |
| job.setJobName("Color Count"); |
| |
| FileInputFormat.setInputPaths(job, new Path(args[0])); |
| FileOutputFormat.setOutputPath(job, new Path(args[1])); |
| |
| job.setInputFormatClass(AvroKeyInputFormat.class); |
| job.setMapperClass(ColorCountMapper.class); |
| AvroJob.setInputKeySchema(job, User.getClassSchema()); |
| job.setMapOutputKeyClass(Text.class); |
| job.setMapOutputValueClass(IntWritable.class); |
| |
| job.setOutputFormatClass(AvroKeyValueOutputFormat.class); |
| job.setReducerClass(ColorCountReducer.class); |
| AvroJob.setOutputKeySchema(job, Schema.create(Schema.Type.STRING)); |
| AvroJob.setOutputValueSchema(job, Schema.create(Schema.Type.INT)); |
| |
| return (job.waitForCompletion(true) ? 0 : 1); |
| } |
| |
| public static void main(String[] args) throws Exception { |
| int res = ToolRunner.run(new MapReduceColorCount(), args); |
| System.exit(res); |
| } |
| } |