Java tutorial
/* * Copyright 2010-2011 the original author or authors. * * Licensed 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 com.ifeng.hadoop.thinker; import java.io.File; import org.apache.hadoop.conf.Configured; import org.apache.hadoop.fs.FileUtil; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Job; 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; /** * @version 0.1 * * @author Hefei Li * * @since Mar 16, 2015 */ public class LogDriver extends Configured implements Tool { @Override public int run(String[] args) throws Exception { if (args.length != 2) { System.err.printf("Usage: %s [generic options] <input> <output>\n", getClass().getSimpleName()); ToolRunner.printGenericCommandUsage(System.err); return -1; } Job job = Job.getInstance(super.getConf()); job.setJarByClass(getClass()); FileUtil.fullyDelete(new File(args[1])); FileInputFormat.addInputPath(job, new Path(args[0])); FileOutputFormat.setOutputPath(job, new Path(args[1])); job.setMapperClass(LogMapper.class); job.setReducerClass(LogReducer.class); job.setCombinerClass(LogReducer.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); return job.waitForCompletion(true) ? 0 : 1; } public static void main(String[] args) throws Exception { int exitCode = ToolRunner.run(new LogDriver(), args); System.exit(exitCode); } }