org.apache.hadoop.mapred.lib

类 InputSampler<K,V>

java.lang.Object

org.apache.hadoop.mapred.lib.InputSampler<K,V>

所有已实现的接口:

Configurable, Tool

public class InputSampler<K,V>
extends Object
implements Tool

Utility for collecting samples and writing a partition file for TotalOrderPartitioner.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	InputSampler.IntervalSampler<K,V> Sample from s splits at regular intervals.
static class	InputSampler.RandomSampler<K,V> Sample from random points in the input.
static interface	InputSampler.Sampler<K,V> Interface to sample using an InputFormat.
static class	InputSampler.SplitSampler<K,V> Samples the first n records from s splits.

构造器概要

构造器

构造器和说明
InputSampler(JobConf conf)

方法概要

方法

限定符和类型	方法和说明
Configuration	getConf() Return the configuration used by this object.
static void	main(String[] args)
int	run(String[] args) Driver for InputSampler from the command line.
void	setConf(Configuration conf) Set the configuration to be used by this object.
static <K,V> void	writePartitionFile(JobConf job, InputSampler.Sampler<K,V> sampler) Write a partition file for the given job, using the Sampler provided.

从类继承的方法 java.lang.Object

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

构造器详细资料

InputSampler

public InputSampler(JobConf conf)

方法详细资料

getConf

public Configuration getConf()

从接口复制的说明: Configurable

Return the configuration used by this object.

指定者:

getConf 在接口中 Configurable

setConf

public void setConf(Configuration conf)

从接口复制的说明: Configurable

Set the configuration to be used by this object.

指定者:

setConf 在接口中 Configurable

writePartitionFile

public static <K,V> void writePartitionFile(JobConf job,
                            InputSampler.Sampler<K,V> sampler)
                               throws IOException

Write a partition file for the given job, using the Sampler provided. Queries the sampler for a sample keyset, sorts by the output key comparator, selects the keys for each rank, and writes to the destination returned from TotalOrderPartitioner.getPartitionFile(org.apache.hadoop.mapred.JobConf).

抛出:

IOException

run

public int run(String[] args)
        throws Exception

Driver for InputSampler from the command line. Configures a JobConf instance and calls writePartitionFile(org.apache.hadoop.mapred.JobConf, org.apache.hadoop.mapred.lib.InputSampler.Sampler<K, V>).

指定者:

run 在接口中 Tool

参数:

args - command specific arguments.

返回:

exit code.

抛出:

Exception

main

public static void main(String[] args)
                 throws Exception

抛出:

Exception