com.yourcompany.hadoop.mapreduce.aggregate.UnionDriver.java Source code

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Here is the source code for com.yourcompany.hadoop.mapreduce.aggregate.UnionDriver.java

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/*
 * 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 com.yourcompany.hadoop.mapreduce.aggregate;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
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.ToolRunner;

import java.io.IOException;

/**
 * Hadoop MapReduce Sample Driver.
 * <p/>
 * <pre>
 *     #hadoop jar JAR_FILE CLASS -libjars LIB_JAR COMMAND_OPTS
 * </pre>
 *
 * @author Edward KIM
 * @version 0.1
 */
public class UnionDriver extends org.apache.hadoop.conf.Configured implements org.apache.hadoop.util.Tool {

    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new UnionDriver(), args);
        System.exit(res);
    }

    public int run(String[] args) throws Exception {
        Job job = new Job();

        parseArguements(args, job);

        job.setJarByClass(UnionDriver.class);

        // Mapper Class
        job.setMapperClass(UnionMapper.class);

        job.setMapOutputKeyClass(NullWritable.class);
        job.setMapOutputValueClass(Text.class);

        // Reducer Task
        job.setNumReduceTasks(1);

        // Run a Hadoop Job
        return job.waitForCompletion(true) ? 0 : 1;
    }

    private void parseArguements(String[] args, Job job) throws IOException {
        for (int i = 0; i < args.length; ++i) {
            if ("-input".equals(args[i])) {
                FileInputFormat.addInputPaths(job, args[++i]);
            } else if ("-output".equals(args[i])) {
                FileOutputFormat.setOutputPath(job, new Path(args[++i]));
            }
        }
    }
}