org.apache.hadoop.mapreduce.lib.output

クラス LazyOutputFormat<K,V>

java.lang.Object

org.apache.hadoop.mapreduce.OutputFormat<K,V>

org.apache.hadoop.mapreduce.lib.output.FilterOutputFormat<K,V>

org.apache.hadoop.mapreduce.lib.output.LazyOutputFormat<K,V>

@InterfaceAudience.Public
 @InterfaceStability.Stable
public class LazyOutputFormat<K,V>
extends FilterOutputFormat<K,V>

A Convenience class that creates output lazily. Use in conjuction with org.apache.hadoop.mapreduce.lib.output.MultipleOutputs to recreate the behaviour of org.apache.hadoop.mapred.lib.MultipleTextOutputFormat (etc) of the old Hadoop API. See MultipleOutputs documentation for more information.

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	OUTPUT_FORMAT

クラスから継承されたフィールド org.apache.hadoop.mapreduce.lib.output.FilterOutputFormat

baseOut

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
LazyOutputFormat()

メソッドのサマリー

修飾子とタイプ	メソッドと説明
void	checkOutputSpecs(JobContext context) Check for validity of the output-specification for the job.
OutputCommitter	getOutputCommitter(TaskAttemptContext context) Get the output committer for this output format.
RecordWriter<K,V>	getRecordWriter(TaskAttemptContext context) Get the RecordWriter for the given task.
static void	setOutputFormatClass(Job job, Class<? extends OutputFormat> theClass) Set the underlying output format for LazyOutputFormat.

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

OUTPUT_FORMAT

public static String OUTPUT_FORMAT

コンストラクタの詳細

LazyOutputFormat

public LazyOutputFormat()

メソッドの詳細

setOutputFormatClass

public static void setOutputFormatClass(Job job,
                                        Class<? extends OutputFormat> theClass)

Set the underlying output format for LazyOutputFormat.

パラメータ:

job - the Job to modify

theClass - the underlying class

getRecordWriter

public RecordWriter<K,V> getRecordWriter(TaskAttemptContext context)
                                  throws IOException,
                                         InterruptedException

クラスからコピーされた説明: OutputFormat

Get the RecordWriter for the given task.

オーバーライド:

getRecordWriter クラス内 FilterOutputFormat<K,V>

パラメータ:

context - the information about the current task.

戻り値:

a RecordWriter to write the output for the job.

例外:

IOException

InterruptedException

checkOutputSpecs

public void checkOutputSpecs(JobContext context)
                      throws IOException,
                             InterruptedException

クラスからコピーされた説明: OutputFormat

Check for validity of the output-specification for the job.

This is to validate the output specification for the job when it is a job is submitted. Typically checks that it does not already exist, throwing an exception when it already exists, so that output is not overwritten.

オーバーライド:

checkOutputSpecs クラス内 FilterOutputFormat<K,V>

パラメータ:

context - information about the job

例外:

IOException - when output should not be attempted

InterruptedException

getOutputCommitter

public OutputCommitter getOutputCommitter(TaskAttemptContext context)
                                   throws IOException,
                                          InterruptedException

クラスからコピーされた説明: OutputFormat

Get the output committer for this output format. This is responsible for ensuring the output is committed correctly.

オーバーライド:

getOutputCommitter クラス内 FilterOutputFormat<K,V>

パラメータ:

context - the task context

戻り値:

an output committer

例外:

IOException

InterruptedException