Java tutorial
/** * 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 es.pic.astro.hadoop.io; import java.io.IOException; import java.io.OutputStream; import java.util.Properties; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.hive.ql.exec.FileSinkOperator.RecordWriter; import org.apache.hadoop.hive.ql.exec.Utilities; import org.apache.hadoop.hive.serde.serdeConstants; import org.apache.hadoop.io.BytesWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.Writable; import org.apache.hadoop.io.WritableComparable; import org.apache.hadoop.mapred.JobConf; import org.apache.hadoop.mapred.Reporter; import org.apache.hadoop.mapred.TextOutputFormat; import org.apache.hadoop.util.Progressable; import org.apache.hadoop.hive.ql.io.HiveOutputFormat; public class BinaryOutputFormat<K extends WritableComparable, V extends Writable> extends TextOutputFormat<K, V> implements HiveOutputFormat<K, V> { /** * create the final out file, and output row by row. After one row is * appended, a configured row separator is appended * * @param jc * the job configuration file * @param outPath * the final output file to be created * @param valueClass * the value class used for create * @param isCompressed * whether the content is compressed or not * @param tableProperties * the tableProperties of this file's corresponding table * @param progress * progress used for status report * @return the RecordWriter */ @Override public RecordWriter getHiveRecordWriter(JobConf jc, Path outPath, Class<? extends Writable> valueClass, boolean isCompressed, Properties tableProperties, Progressable progress) throws IOException { FileSystem fs = outPath.getFileSystem(jc); final OutputStream outStream = Utilities.createCompressedStream(jc, fs.create(outPath, progress), isCompressed); return new RecordWriter() { @Override public void write(Writable r) throws IOException { if (r instanceof Text) { Text tr = (Text) r; outStream.write(tr.getBytes(), 0, tr.getLength()); } else { // DynamicSerDe always writes out BytesWritable BytesWritable bw = (BytesWritable) r; outStream.write(bw.get(), 0, bw.getSize()); } } @Override public void close(boolean abort) throws IOException { outStream.close(); } }; } protected static class IgnoreKeyWriter<K extends WritableComparable, V extends Writable> implements org.apache.hadoop.mapred.RecordWriter<K, V> { private final org.apache.hadoop.mapred.RecordWriter<K, V> mWriter; public IgnoreKeyWriter(org.apache.hadoop.mapred.RecordWriter<K, V> writer) { this.mWriter = writer; } @Override public synchronized void write(K key, V value) throws IOException { this.mWriter.write(null, value); } @Override public void close(Reporter reporter) throws IOException { this.mWriter.close(reporter); } } @Override public org.apache.hadoop.mapred.RecordWriter<K, V> getRecordWriter(FileSystem ignored, JobConf job, String name, Progressable progress) throws IOException { return new IgnoreKeyWriter<K, V>(super.getRecordWriter(ignored, job, name, progress)); } }