org.apache.hadoop.hbase.mapred
Class TableInputFormat

java.lang.Object
  org.apache.hadoop.hbase.mapred.TableInputFormat

All Implemented Interfaces:

InputFormat<HStoreKey,MapWritable>, JobConfigurable

public class TableInputFormat
extends Object
implements InputFormat<HStoreKey,MapWritable>, JobConfigurable

Convert HBase tabular data into a format that is consumable by Map/Reduce

Field Summary

static String

COLUMN_LIST space delimited list of columns

Constructor Summary

TableInputFormat()

Method Summary

void	configure(JobConf job) Initializes a new instance from a JobConf.
RecordReader<HStoreKey,MapWritable>	getRecordReader(InputSplit split, JobConf job, Reporter reporter) Get the RecordReader for the given InputSplit.
InputSplit[]	getSplits(JobConf job, int numSplits) A split will be created for each HRegion of the input table
void	validateInput(JobConf job) Check for validity of the input-specification for the job.

Methods inherited from class java.lang.Object

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

Field Detail

COLUMN_LIST

public static final String COLUMN_LIST

space delimited list of columns

See Also:

for column name wildcards, Constant Field Values

Constructor Detail

TableInputFormat

public TableInputFormat()

Method Detail

getRecordReader

public RecordReader<HStoreKey,MapWritable> getRecordReader(InputSplit split,
                                                           JobConf job,
                                                           Reporter reporter)
                                                    throws IOException

Description copied from interface: 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.

Specified by:

getRecordReader in interface InputFormat<HStoreKey,MapWritable>

Parameters:

split - the InputSplit

job - the job that this split belongs to

Returns:

a RecordReader

Throws:

IOException

getSplits

public InputSplit[] getSplits(JobConf job,
                              int numSplits)
                       throws IOException

A split will be created for each HRegion of the input table

Specified by:

getSplits in interface InputFormat<HStoreKey,MapWritable>

Parameters:

job - job configuration.

numSplits - the desired number of splits, a hint.

Returns:

an array of InputSplits for the job.

Throws:

IOException

See Also:

InputFormat.getSplits(org.apache.hadoop.mapred.JobConf, int)

configure

public void configure(JobConf job)

Description copied from interface: JobConfigurable

Initializes a new instance from a JobConf.

Specified by:

configure in interface JobConfigurable

Parameters:

job - the configuration

validateInput

public void validateInput(JobConf job)
                   throws IOException

Description copied from interface: InputFormat

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

This method is used to validate the input directories when a job is submitted so that the JobClient can fail early, with an useful error message, in case of errors. For e.g. input directory does not exist.

Specified by:

validateInput in interface InputFormat<HStoreKey,MapWritable>

Parameters:

job - job configuration.

Throws:

InvalidInputException - if the job does not have valid input

IOException