com.pivotal.hawq.mapreduce.demo.HAWQInputFormatDemo.java Source code

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Here is the source code for com.pivotal.hawq.mapreduce.demo.HAWQInputFormatDemo.java

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package com.pivotal.hawq.mapreduce.demo;

/*
 * 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.
 */

import com.pivotal.hawq.mapreduce.HAWQInputFormat;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * A demo of how to use {@link com.pivotal.hawq.mapreduce.HAWQInputFormat}
 * to output all rows in a HAWQ's table.
 * <p>
 * This demo uses {@code HAWQInputFormat.setInput(conf, db_url, username, password, tableName)}
 * to set table's metadata.
 */
public class HAWQInputFormatDemo extends Configured implements Tool {

    private static void printUsage() {
        System.out.println("HAWQInputFormatDemo <db_url> <table_name> <output_path> [username] [password]");
        ToolRunner.printGenericCommandUsage(System.out);
    }

    @Override
    public int run(String[] args) throws Exception {
        if (args.length < 3) {
            printUsage();
        }

        String dbURL = args[0];
        String tableName = args[1];
        String outputPath = args[2];
        String username = (args.length >= 4) ? args[3] : null;
        String password = (args.length >= 5) ? args[4] : null;

        Job job = new Job(getConf(), "HAWQInputFormatDemo");
        job.setJarByClass(HAWQInputFormatDemo.class);

        job.setInputFormatClass(HAWQInputFormat.class);

        HAWQInputFormat.setInput(job.getConfiguration(), dbURL, username, password, tableName);
        FileOutputFormat.setOutputPath(job, new Path(outputPath));

        job.setMapperClass(HAWQEchoMapper.class);
        job.setNumReduceTasks(0);

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

        long startTime = System.currentTimeMillis();
        int returnCode = job.waitForCompletion(true) ? 0 : 1;
        long endTime = System.currentTimeMillis();

        System.out.println("Time elapsed: " + (endTime - startTime) + " milliseconds");

        return returnCode;
    }

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