Java tutorial
/* * 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 io.covert.dns.parse; import io.covert.util.UniqueKeyOnlyReducer; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.conf.Configured; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapred.JobClient; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat; import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; public class ParseJob extends Configured implements Tool { public static void main(String[] args) throws Exception { ToolRunner.run(new ParseJob(), args); } @Override public int run(String[] args) throws Exception { String inDir = args[0]; String outDir = args[1]; Configuration conf = getConf(); Job job = new Job(conf); job.setJobName(ParseJob.class.getSimpleName() + ": inDir=" + inDir + ", outDir=" + outDir); job.setJarByClass(getClass()); job.setMapperClass(ParseMapper.class); job.setReducerClass(UniqueKeyOnlyReducer.class); job.setNumReduceTasks(new JobClient(new JobConf(conf)).getClusterStatus().getTaskTrackers()); job.setMapOutputKeyClass(Text.class); job.setMapOutputValueClass(Text.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); job.setInputFormatClass(SequenceFileInputFormat.class); FileInputFormat.setInputPaths(job, new Path(inDir)); job.setOutputFormatClass(SequenceFileOutputFormat.class); SequenceFileOutputFormat.setOutputPath(job, new Path(outDir)); SequenceFileOutputFormat.setCompressOutput(job, true); job.submit(); return job.waitForCompletion(true) ? 0 : 1; } }