com.yourcompany.hadoop.mapreduce.hcatalog.HCatalogExampleDriver.java Source code

Introduction

Here is the source code for com.yourcompany.hadoop.mapreduce.hcatalog.HCatalogExampleDriver.java

Source

/*
 * 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.hcatalog;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
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 org.apache.hcatalog.data.DefaultHCatRecord;
import org.apache.hcatalog.data.schema.HCatSchema;
import org.apache.hcatalog.mapreduce.HCatInputFormat;
import org.apache.hcatalog.mapreduce.HCatOutputFormat;
import org.apache.hcatalog.mapreduce.OutputJobInfo;

import java.io.IOException;

public class HCatalogExampleDriver 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 HCatalogExampleDriver(), args);
        System.exit(res);
    }

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

        job.setJarByClass(HCatalogExampleDriver.class);

        job.setInputFormatClass(HCatInputFormat.class);
        job.setOutputFormatClass(HCatOutputFormat.class);

        job.setMapperClass(HCatalogExampleMapper.class);
        job.setReducerClass(HCatalogExampleReducer.class);

        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(IntWritable.class);
        job.setOutputKeyClass(WritableComparable.class);
        job.setOutputValueClass(DefaultHCatRecord.class);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);

        return job.waitForCompletion(true) ? 0 : 1;
    }

    private void parseArguements(String[] args, Job job) throws IOException {

        String outputTableName = null;
        String dbName = null;
        String inputTableName = null;

        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]));
            } else if ("-dbName".equals(args[i])) {
                dbName = args[++i];
            } else if ("-inputTableName".equals(args[i])) {
                inputTableName = args[++i];
            } else if ("-outputTableName".equals(args[i])) {
                outputTableName = args[++i];
            }
        }

        HCatInputFormat.setInput(job.getConfiguration(), dbName, inputTableName);
        HCatOutputFormat.setOutput(job, OutputJobInfo.create(dbName, outputTableName, null));
        HCatSchema s = HCatOutputFormat.getTableSchema(job.getConfiguration());
        HCatOutputFormat.setSchema(job, s);
    }
}