com.cloudera.sqoop.mapreduce.RawKeyTextOutputFormat.java Source code

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Here is the source code for com.cloudera.sqoop.mapreduce.RawKeyTextOutputFormat.java

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/**
 * Licensed to Cloudera, Inc. under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  Cloudera, 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 com.cloudera.sqoop.mapreduce;

import java.io.DataOutputStream;
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.GzipCodec;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.util.*;

/** An {@link OutputFormat} that writes plain text files.
 * Only writes the key. Does not write any delimiter/newline after the key.
 */
public class RawKeyTextOutputFormat<K, V> extends FileOutputFormat<K, V> {

    protected static class RawKeyRecordWriter<K, V> extends RecordWriter<K, V> {
        private static final String UTF8 = "UTF-8";

        protected DataOutputStream out;

        public RawKeyRecordWriter(DataOutputStream out) {
            this.out = out;
        }

        /**
         * Write the object to the byte stream, handling Text as a special
         * case.
         * @param o the object to print
         * @throws IOException if the write throws, we pass it on
         */
        private void writeObject(Object o) throws IOException {
            if (o instanceof Text) {
                Text to = (Text) o;
                out.write(to.getBytes(), 0, to.getLength());
            } else {
                out.write(o.toString().getBytes(UTF8));
            }
        }

        public synchronized void write(K key, V value) throws IOException {
            writeObject(key);
        }

        public synchronized void close(TaskAttemptContext context) throws IOException {
            out.close();
        }
    }

    public RecordWriter<K, V> getRecordWriter(TaskAttemptContext context) throws IOException {
        boolean isCompressed = getCompressOutput(context);
        Configuration conf = context.getConfiguration();
        String ext = "";
        CompressionCodec codec = null;

        if (isCompressed) {
            // create the named codec
            Class<? extends CompressionCodec> codecClass = getOutputCompressorClass(context, GzipCodec.class);
            codec = ReflectionUtils.newInstance(codecClass, conf);

            ext = codec.getDefaultExtension();
        }

        Path file = getDefaultWorkFile(context, ext);
        FileSystem fs = file.getFileSystem(conf);
        FSDataOutputStream fileOut = fs.create(file, false);
        DataOutputStream ostream = fileOut;

        if (isCompressed) {
            ostream = new DataOutputStream(codec.createOutputStream(fileOut));
        }

        return new RawKeyRecordWriter<K, V>(ostream);
    }
}