infinidb.hadoop.db.InfiniDBOutputFormat.java Source code

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Here is the source code for infinidb.hadoop.db.InfiniDBOutputFormat.java

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/*
 * Copyright (c) 2014 InfiniDB, Inc.
 *
 * InfiniDB, Inc. 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 infinidb.hadoop.db;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.OutputFormat;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.util.Progressable;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.mapred.lib.db.*;

/**
 * A OutputFormat that sends the reduce output to a SQL table.
 * <p> 
 * {@link DBOutputFormat} accepts &lt;key,value&gt; pairs, where 
 * key has a type extending DBWritable. Returned {@link RecordWriter} 
 * writes <b>only the key</b> to the database with a batch SQL query.  
 * 
 */
public class InfiniDBOutputFormat<K /*extends DBWritable*/, V> implements OutputFormat<K, V> {

    private static final Log LOG = LogFactory.getLog(InfiniDBOutputFormat.class);

    /**
     * A RecordWriter that writes the reduce output to a SQL table
     */
    protected class DBRecordWriter implements RecordWriter<K, V> {

        private Connection connection;
        private PreparedStatement statement;

        protected DBRecordWriter() throws SQLException {
        }

        /** {@inheritDoc} */
        public void close(Reporter reporter) throws IOException {
        }

        /** {@inheritDoc} */
        public void write(K key, V value) throws IOException {
        }
    }

    /** {@inheritDoc} */
    public void checkOutputSpecs(FileSystem filesystem, JobConf job) throws IOException {
    }

    /** {@inheritDoc} */
    public RecordWriter<K, V> getRecordWriter(FileSystem filesystem, JobConf job, String name,
            Progressable progress) throws IOException {
        try {
            return new DBRecordWriter();
        } catch (Exception ex) {
            throw new IOException(ex.getMessage());
        }
    }

    /**
      * Initializes the reduce-part of the job with the appropriate output settings
      * 
      * @param job
      *          The job
      * @param tableName
      *          The table to insert data into
      * @param fieldNames
      *          The field names in the table. If unknown, supply the appropriate
      *          number of nulls.
      */
    public static void setOutput(JobConf job, String schemaName, String... tableNames) {
        job.setOutputFormat(InfiniDBOutputFormat.class);
        job.setReduceSpeculativeExecution(false);

        InfiniDBConfiguration dbConf = new InfiniDBConfiguration(job);
        dbConf.setOutputSchemaName(schemaName);
        dbConf.setOutputTableNames(tableNames);
    }

    /**
     * Initializes the reduce-part of the job with the appropriate output settings
     * 
     * @param job
     *          The job
     * @param tableName
     *          The table to insert data into
     * @param fieldNames
     *          The field names in the table. If unknown, supply the appropriate
     *          number of nulls.
     */
    public static void setOutput(JobConf job, String schemaName) {
        job.setOutputFormat(InfiniDBOutputFormat.class);
        job.setReduceSpeculativeExecution(false);

        InfiniDBConfiguration dbConf = new InfiniDBConfiguration(job);

        dbConf.setOutputSchemaName(schemaName);
    }
}