001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019 package org.apache.hadoop.mapreduce.lib.input;
020
021 import org.apache.hadoop.classification.InterfaceAudience;
022 import org.apache.hadoop.classification.InterfaceStability;
023 import org.apache.hadoop.fs.Path;
024 import org.apache.hadoop.io.LongWritable;
025 import org.apache.hadoop.io.Text;
026 import org.apache.hadoop.io.compress.CompressionCodec;
027 import org.apache.hadoop.io.compress.CompressionCodecFactory;
028 import org.apache.hadoop.io.compress.SplittableCompressionCodec;
029 import org.apache.hadoop.mapreduce.InputFormat;
030 import org.apache.hadoop.mapreduce.InputSplit;
031 import org.apache.hadoop.mapreduce.JobContext;
032 import org.apache.hadoop.mapreduce.RecordReader;
033 import org.apache.hadoop.mapreduce.TaskAttemptContext;
034
035 import com.google.common.base.Charsets;
036
037 /** An {@link InputFormat} for plain text files. Files are broken into lines.
038 * Either linefeed or carriage-return are used to signal end of line. Keys are
039 * the position in the file, and values are the line of text.. */
040 @InterfaceAudience.Public
041 @InterfaceStability.Stable
042 public class TextInputFormat extends FileInputFormat<LongWritable, Text> {
043
044 @Override
045 public RecordReader<LongWritable, Text>
046 createRecordReader(InputSplit split,
047 TaskAttemptContext context) {
048 String delimiter = context.getConfiguration().get(
049 "textinputformat.record.delimiter");
050 byte[] recordDelimiterBytes = null;
051 if (null != delimiter)
052 recordDelimiterBytes = delimiter.getBytes(Charsets.UTF_8);
053 return new LineRecordReader(recordDelimiterBytes);
054 }
055
056 @Override
057 protected boolean isSplitable(JobContext context, Path file) {
058 final CompressionCodec codec =
059 new CompressionCodecFactory(context.getConfiguration()).getCodec(file);
060 if (null == codec) {
061 return true;
062 }
063 return codec instanceof SplittableCompressionCodec;
064 }
065
066 }