org.apache.hadoop.mapred

クラス FixedLengthInputFormat

java.lang.Object

org.apache.hadoop.mapred.FileInputFormat<LongWritable,BytesWritable>

org.apache.hadoop.mapred.FixedLengthInputFormat

すべての実装されたインタフェース:

InputFormat<LongWritable,BytesWritable>, JobConfigurable

@InterfaceAudience.Public
 @InterfaceStability.Stable
public class FixedLengthInputFormat
extends FileInputFormat<LongWritable,BytesWritable>
implements JobConfigurable

FixedLengthInputFormat is an input format used to read input files which contain fixed length records. The content of a record need not be text. It can be arbitrary binary data. Users must configure the record length property by calling: FixedLengthInputFormat.setRecordLength(conf, recordLength);

or conf.setInt(FixedLengthInputFormat.FIXED_RECORD_LENGTH, recordLength);

関連項目:

FixedLengthRecordReader

フィールドのサマリー

フィールド

修飾子とタイプ	フィールドと説明
static String	FIXED_RECORD_LENGTH

クラスから継承されたフィールド org.apache.hadoop.mapred.FileInputFormat

INPUT_DIR_RECURSIVE, LOG, NUM_INPUT_FILES

コンストラクタのサマリー

コンストラクタ

コンストラクタと説明
FixedLengthInputFormat()

メソッドのサマリー

修飾子とタイプ	メソッドと説明
void	configure(JobConf conf) Initializes a new instance from a JobConf.
static int	getRecordLength(Configuration conf) Get record length value
RecordReader<LongWritable,BytesWritable>	getRecordReader(InputSplit genericSplit, JobConf job, Reporter reporter) Get the RecordReader for the given InputSplit.
protected boolean	isSplitable(FileSystem fs, Path file) Is the given filename splittable?
static void	setRecordLength(Configuration conf, int recordLength) Set the length of each record

クラスから継承されたメソッド org.apache.hadoop.mapred.FileInputFormat

addInputPath, addInputPathRecursively, addInputPaths, computeSplitSize, getBlockIndex, getInputPathFilter, getInputPaths, getSplitHosts, getSplits, listStatus, makeSplit, makeSplit, setInputPathFilter, setInputPaths, setInputPaths, setMinSplitSize

クラスから継承されたメソッド java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

フィールドの詳細

FIXED_RECORD_LENGTH

public static final String FIXED_RECORD_LENGTH

関連項目:

定数フィールド値

コンストラクタの詳細

FixedLengthInputFormat

public FixedLengthInputFormat()

メソッドの詳細

setRecordLength

public static void setRecordLength(Configuration conf,
                                   int recordLength)

Set the length of each record

パラメータ:

conf - configuration

recordLength - the length of a record

getRecordLength

public static int getRecordLength(Configuration conf)

Get record length value

パラメータ:

conf - configuration

戻り値:

the record length, zero means none was set

configure

public void configure(JobConf conf)

インタフェースからコピーされた説明: JobConfigurable

Initializes a new instance from a JobConf.

定義:

configure インタフェース内 JobConfigurable

パラメータ:

conf - the configuration

getRecordReader

public RecordReader<LongWritable,BytesWritable> getRecordReader(InputSplit genericSplit,
                                                                JobConf job,
                                                                Reporter reporter)
                                                         throws IOException

インタフェースからコピーされた説明: InputFormat

Get the RecordReader for the given InputSplit.

It is the responsibility of the RecordReader to respect record boundaries while processing the logical split to present a record-oriented view to the individual task.

定義:

getRecordReader インタフェース内 InputFormat<LongWritable,BytesWritable>

定義:

getRecordReader クラス内 FileInputFormat<LongWritable,BytesWritable>

パラメータ:

genericSplit - the InputSplit

job - the job that this split belongs to

戻り値:

a RecordReader

例外:

IOException

isSplitable

protected boolean isSplitable(FileSystem fs,
                              Path file)

クラスからコピーされた説明: FileInputFormat

Is the given filename splittable? Usually, true, but if the file is stream compressed, it will not be. The default implementation in FileInputFormat always returns true. Implementations that may deal with non-splittable files must override this method. FileInputFormat implementations can override this and return false to ensure that individual input files are never split-up so that Mappers process entire files.

オーバーライド:

isSplitable クラス内 FileInputFormat<LongWritable,BytesWritable>

パラメータ:

fs - the file system that the file is on

file - the file name to check

戻り値:

is this file splitable?