org.apache.hadoop.hbase.mapreduce

类 TableRecordReader

java.lang.Object

org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

org.apache.hadoop.hbase.mapreduce.TableRecordReader

所有已实现的接口:

Closeable, AutoCloseable

@InterfaceAudience.Public
@InterfaceStability.Stable
public class TableRecordReader
extends org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

Iterate over an HBase table data, return (ImmutableBytesWritable, Result) pairs.

构造器概要

构造器

构造器和说明
TableRecordReader()

方法概要

方法

限定符和类型	方法和说明
void	close() Closes the split.
ImmutableBytesWritable	getCurrentKey() Returns the current key.
Result	getCurrentValue() Returns the current value.
float	getProgress() The current progress of the record reader through its data.
void	initialize(org.apache.hadoop.mapreduce.InputSplit inputsplit, org.apache.hadoop.mapreduce.TaskAttemptContext context) Initializes the reader.
boolean	nextKeyValue() Positions the record reader to the next record.
void	restart(byte[] firstRow) Restart from survivable exceptions by creating a new scanner.
void	setHTable(Table htable) 已过时。 Use setTable() instead.
void	setScan(Scan scan) Sets the scan defining the actual details like columns etc.
void	setTable(Table table)

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

TableRecordReader

public TableRecordReader()

方法详细资料

restart

public void restart(byte[] firstRow)
             throws IOException

Restart from survivable exceptions by creating a new scanner.

参数:

firstRow - The first row to start at.

抛出:

IOException - When restarting fails.

setHTable

@Deprecated
public void setHTable(Table htable)

已过时。 Use setTable() instead.

Sets the HBase table.

参数:

htable - The table to scan.

setTable

public void setTable(Table table)

参数:

table - the Table to scan.

setScan

public void setScan(Scan scan)

Sets the scan defining the actual details like columns etc.

参数:

scan - The scan to set.

close

public void close()

Closes the split.

指定者:

close 在接口中 Closeable

指定者:

close 在接口中 AutoCloseable

指定者:

close 在类中 org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

另请参阅:

RecordReader.close()

getCurrentKey

public ImmutableBytesWritable getCurrentKey()
                                     throws IOException,
                                            InterruptedException

Returns the current key.

指定者:

getCurrentKey 在类中 org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

返回:

The current key.

抛出:

IOException

InterruptedException - When the job is aborted.

另请参阅:

RecordReader.getCurrentKey()

getCurrentValue

public Result getCurrentValue()
                       throws IOException,
                              InterruptedException

Returns the current value.

指定者:

getCurrentValue 在类中 org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

返回:

The current value.

抛出:

IOException - When the value is faulty.

InterruptedException - When the job is aborted.

另请参阅:

RecordReader.getCurrentValue()

initialize

public void initialize(org.apache.hadoop.mapreduce.InputSplit inputsplit,
              org.apache.hadoop.mapreduce.TaskAttemptContext context)
                throws IOException,
                       InterruptedException

Initializes the reader.

指定者:

initialize 在类中 org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

参数:

inputsplit - The split to work with.

context - The current task context.

抛出:

IOException - When setting up the reader fails.

InterruptedException - When the job is aborted.

另请参阅:

RecordReader.initialize( org.apache.hadoop.mapreduce.InputSplit, org.apache.hadoop.mapreduce.TaskAttemptContext)

nextKeyValue

public boolean nextKeyValue()
                     throws IOException,
                            InterruptedException

Positions the record reader to the next record.

指定者:

nextKeyValue 在类中 org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

返回:

true if there was another record.

抛出:

IOException - When reading the record failed.

InterruptedException - When the job was aborted.

另请参阅:

RecordReader.nextKeyValue()

getProgress

public float getProgress()

The current progress of the record reader through its data.

指定者:

getProgress 在类中 org.apache.hadoop.mapreduce.RecordReader<ImmutableBytesWritable,Result>

返回:

A number between 0.0 and 1.0, the fraction of the data read.

另请参阅:

RecordReader.getProgress()