public class PipeMapper extends PipeMapRed implements Mapper
LOG, outerrThreadsThrowable
Constructor and Description |
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PipeMapper() |
Modifier and Type | Method and Description |
---|---|
void |
close() |
void |
configure(JobConf job)
Initializes a new instance from a
JobConf . |
byte[] |
getFieldSeparator()
Returns the field separator to be used.
|
byte[] |
getInputSeparator()
Returns the input separator to be used.
|
int |
getNumOfKeyFields()
Returns the number of key fields.
|
void |
map(Object key,
Object value,
OutputCollector output,
Reporter reporter)
Maps a single input key/value pair into an intermediate key/value pair.
|
getClientInput, getClientOutput, getConfiguration, getContext, mapRedFinished
public void configure(JobConf job)
JobConfigurable
JobConf
.configure
in interface JobConfigurable
configure
in class PipeMapRed
job
- the configurationpublic void map(Object key, Object value, OutputCollector output, Reporter reporter) throws IOException
Mapper
Output pairs need not be of the same types as input pairs. A given
input pair may map to zero or many output pairs. Output pairs are
collected with calls to
OutputCollector.collect(Object,Object)
.
Applications can use the Reporter
provided to report progress
or just indicate that they are alive. In scenarios where the application
takes significant amount of time to process individual key/value
pairs, this is crucial since the framework might assume that the task has
timed-out and kill that task. The other way of avoiding this is to set
mapreduce.task.timeout to a high-enough value (or even zero for no
time-outs).
map
in interface Mapper
key
- the input key.value
- the input value.output
- collects mapped keys and values.reporter
- facility to report progress.IOException
public void close()
close
in interface Closeable
close
in interface AutoCloseable
public byte[] getInputSeparator()
PipeMapRed
getInputSeparator
in class PipeMapRed
public byte[] getFieldSeparator()
PipeMapRed
getFieldSeparator
in class PipeMapRed
public int getNumOfKeyFields()
PipeMapRed
getNumOfKeyFields
in class PipeMapRed
Copyright © 2013 Apache Software Foundation. All rights reserved.