org.apache.hadoop.mapreduce.task

Class MapContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

java.lang.Object

org.apache.hadoop.mapreduce.task.JobContextImpl

org.apache.hadoop.mapreduce.task.TaskAttemptContextImpl

org.apache.hadoop.mapreduce.task.TaskInputOutputContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

org.apache.hadoop.mapreduce.task.MapContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

Type Parameters:

KEYIN - the key input type to the Mapper

VALUEIN - the value input type to the Mapper

KEYOUT - the key output type from the Mapper

VALUEOUT - the value output type from the Mapper

All Implemented Interfaces:

JobContext, MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>, TaskAttemptContext, TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>, org.apache.hadoop.util.Progressable

public class MapContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>
extends TaskInputOutputContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>
implements MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

The context that is given to the Mapper.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.task.TaskAttemptContextImpl

TaskAttemptContextImpl.DummyReporter

Field Summary

Fields inherited from class org.apache.hadoop.mapreduce.task.JobContextImpl

conf, credentials, ugi

Fields inherited from interface org.apache.hadoop.mapreduce.JobContext

CACHE_ARCHIVES_VISIBILITIES, CACHE_FILE_VISIBILITIES, COMBINE_CLASS_ATTR, INPUT_FORMAT_CLASS_ATTR, JAR_UNPACK_PATTERN, JOB_ACL_MODIFY_JOB, JOB_ACL_VIEW_JOB, JOB_CANCEL_DELEGATION_TOKEN, JOB_NAMENODES, MAP_CLASS_ATTR, MAP_MEMORY_PHYSICAL_MB, MAP_OUTPUT_COLLECTOR_CLASS_ATTR, MAPREDUCE_TASK_CLASSPATH_PRECEDENCE, OUTPUT_FORMAT_CLASS_ATTR, PARTITIONER_CLASS_ATTR, REDUCE_CLASS_ATTR, REDUCE_MEMORY_PHYSICAL_MB, SHUFFLE_CONSUMER_PLUGIN_ATTR, USER_LOG_RETAIN_HOURS

Constructor Summary

Constructors

Constructor and Description
MapContextImpl(org.apache.hadoop.conf.Configuration conf, TaskAttemptID taskid, RecordReader<KEYIN,VALUEIN> reader, RecordWriter<KEYOUT,VALUEOUT> writer, OutputCommitter committer, StatusReporter reporter, InputSplit split)

Method Summary

Methods

Modifier and Type	Method and Description
KEYIN	getCurrentKey() Get the current key.
VALUEIN	getCurrentValue() Get the current value.
InputSplit	getInputSplit() Get the input split for this map.
boolean	nextKeyValue() Advance to the next key, value pair, returning null if at end.

Methods inherited from class org.apache.hadoop.mapreduce.task.TaskInputOutputContextImpl

getOutputCommitter, write

Methods inherited from class org.apache.hadoop.mapreduce.task.TaskAttemptContextImpl

getCounter, getCounter, getStatus, getTaskAttemptID, progress, setStatus, setStatusString

Methods inherited from class org.apache.hadoop.mapreduce.task.JobContextImpl

getArchiveClassPaths, getArchiveTimestamps, getCacheArchives, getCacheFiles, getCombinerClass, getCombinerKeyGroupingComparator, getConfiguration, getCredentials, getFileClassPaths, getFileTimestamps, getGroupingComparator, getInputFormatClass, getJar, getJobID, getJobName, getJobSetupCleanupNeeded, getLocalCacheArchives, getLocalCacheFiles, getMapOutputKeyClass, getMapOutputValueClass, getMapperClass, getMaxMapAttempts, getMaxReduceAttempts, getNumReduceTasks, getOutputFormatClass, getOutputKeyClass, getOutputValueClass, getPartitionerClass, getProfileEnabled, getProfileParams, getProfileTaskRange, getReducerClass, getSortComparator, getSymlink, getUser, getWorkingDirectory, setJobID, userClassesTakesPrecedence

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.mapreduce.TaskInputOutputContext

getOutputCommitter, write

Methods inherited from interface org.apache.hadoop.mapreduce.TaskAttemptContext

getCounter, getCounter, getStatus, getTaskAttemptID, setStatus

Methods inherited from interface org.apache.hadoop.mapreduce.JobContext

getArchiveClassPaths, getArchiveTimestamps, getCacheArchives, getCacheFiles, getCombinerClass, getCombinerKeyGroupingComparator, getConfiguration, getCredentials, getFileClassPaths, getFileTimestamps, getGroupingComparator, getInputFormatClass, getJar, getJobID, getJobName, getJobSetupCleanupNeeded, getLocalCacheArchives, getLocalCacheFiles, getMapOutputKeyClass, getMapOutputValueClass, getMapperClass, getMaxMapAttempts, getMaxReduceAttempts, getNumReduceTasks, getOutputFormatClass, getOutputKeyClass, getOutputValueClass, getPartitionerClass, getProfileEnabled, getProfileParams, getReducerClass, getSortComparator, getSymlink, getUser, getWorkingDirectory, userClassesTakesPrecedence

Methods inherited from interface org.apache.hadoop.util.Progressable

progress

Constructor Detail

MapContextImpl

public MapContextImpl(org.apache.hadoop.conf.Configuration conf,
              TaskAttemptID taskid,
              RecordReader<KEYIN,VALUEIN> reader,
              RecordWriter<KEYOUT,VALUEOUT> writer,
              OutputCommitter committer,
              StatusReporter reporter,
              InputSplit split)

Method Detail

getInputSplit

public InputSplit getInputSplit()

Get the input split for this map.

Specified by:

getInputSplit in interface MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

getCurrentKey

public KEYIN getCurrentKey()
                    throws java.io.IOException,
                           java.lang.InterruptedException

Description copied from class: TaskInputOutputContextImpl

Get the current key.

Specified by:

getCurrentKey in interface TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

Specified by:

getCurrentKey in class TaskInputOutputContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

Returns:

the current key object or null if there isn't one

Throws:

java.io.IOException

java.lang.InterruptedException

getCurrentValue

public VALUEIN getCurrentValue()
                        throws java.io.IOException,
                               java.lang.InterruptedException

Description copied from class: TaskInputOutputContextImpl

Get the current value.

Specified by:

getCurrentValue in interface TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

Specified by:

getCurrentValue in class TaskInputOutputContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

Returns:

the value object that was read into

Throws:

java.io.IOException

java.lang.InterruptedException

nextKeyValue

public boolean nextKeyValue()
                     throws java.io.IOException,
                            java.lang.InterruptedException

Description copied from class: TaskInputOutputContextImpl

Advance to the next key, value pair, returning null if at end.

Specified by:

nextKeyValue in interface TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

Specified by:

nextKeyValue in class TaskInputOutputContextImpl<KEYIN,VALUEIN,KEYOUT,VALUEOUT>

Returns:

the key object that was read into, or null if no more

Throws:

java.io.IOException

java.lang.InterruptedException