org.apache.jena.tdbloader4.FirstDriver.java Source code

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Here is the source code for org.apache.jena.tdbloader4.FirstDriver.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 org.apache.jena.tdbloader4;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
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.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.jena.tdbloader4.io.NQuadsInputFormat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class FirstDriver extends Configured implements Tool {

    private static final Logger log = LoggerFactory.getLogger(FirstDriver.class);

    public FirstDriver() {
        super();
        log.debug("constructed with no configuration.");
    }

    public FirstDriver(Configuration configuration) {
        super(configuration);
        log.debug("constructed with configuration.");
    }

    @Override
    public int run(String[] args) throws Exception {
        if (args.length != 2) {
            System.err.printf("Usage: %s [generic options] <input> <output>\n", getClass().getName());
            ToolRunner.printGenericCommandUsage(System.err);
            return -1;
        }

        Configuration configuration = getConf();
        boolean useCompression = configuration.getBoolean(Constants.OPTION_USE_COMPRESSION,
                Constants.OPTION_USE_COMPRESSION_DEFAULT);

        if (useCompression) {
            configuration.setBoolean("mapred.compress.map.output", true);
            configuration.set("mapred.output.compression.type", "BLOCK");
            configuration.set("mapred.map.output.compression.codec", "org.apache.hadoop.io.compress.GzipCodec");
        }

        Job job = new Job(configuration);
        job.setJobName(Constants.NAME_FIRST);
        job.setJarByClass(getClass());

        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        job.setInputFormatClass(NQuadsInputFormat.class);
        job.setMapperClass(FirstMapper.class);
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(NullWritable.class);

        job.setReducerClass(FirstReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(LongWritable.class);

        Utils.setReducers(job, configuration, log);

        job.setOutputFormatClass(TextOutputFormat.class);

        if (log.isDebugEnabled())
            Utils.log(job, log);

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

    public static void main(String[] args) throws Exception {
        log.debug("main method: {}", Utils.toString(args));
        int exitCode = ToolRunner.run(new FirstDriver(), args);
        System.exit(exitCode);
    }

}