cz.seznam.euphoria.hadoop.output.HadoopTextFileSink.java Source code

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Here is the source code for cz.seznam.euphoria.hadoop.output.HadoopTextFileSink.java

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/**
 * Copyright 2016 Seznam.cz, a.s.
 *
 * Licensed 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 cz.seznam.euphoria.hadoop.output;

import cz.seznam.euphoria.core.client.io.DataSink;
import cz.seznam.euphoria.core.client.io.DataSinkFactory;
import cz.seznam.euphoria.core.util.Settings;
import cz.seznam.euphoria.hadoop.HadoopUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;

import java.net.URI;

/**
 * A convenience data sink based on hadoop's {@link TextOutputFormat}.
 *
 * @param <K> the type of keys emitted
 * @param <V> the type of values emitted
 */
public class HadoopTextFileSink<K, V> extends HadoopSink<K, V> {

    /**
     * A standard URI based factory for instance of {@link HadoopTextFileSink}.
     */
    public static final class Factory implements DataSinkFactory {
        @Override
        @SuppressWarnings("unchecked")
        public <T> DataSink<T> get(URI uri, Settings settings) {
            return (DataSink<T>) new HadoopTextFileSink(uri.toString(), HadoopUtils.createConfiguration(settings));
        }
    }

    /**
     * Convenience constructor invoking {@link #HadoopTextFileSink(String, Configuration)}
     * with a newly created hadoop configuration.
     *
     * @param path the path where to place the output to
     *
     * @throws NullPointerException if any of the given parameters is {@code null}
     */
    public HadoopTextFileSink(String path) {
        this(path, new Configuration());
    }

    /**
     * Constructs a data sink based on hadoop's {@link TextOutputFormat}.
     * The specified path is automatically set/overridden in the given hadoop
     * configuration.
     *
     * @param path the path to read data from
     * @param hadoopConfig the hadoop configuration to build on top of
     *
     * @throws NullPointerException if any of the parameters is {@code null}
     */
    @SuppressWarnings("unchecked")
    public HadoopTextFileSink(String path, Configuration hadoopConfig) {
        super((Class) TextOutputFormat.class, hadoopConfig);
        hadoopConfig.set(FileOutputFormat.OUTDIR, path);
    }
}