org.apache.hadoop.mapreduce.lib.input

类 SequenceFileAsTextRecordReader

java.lang.Object

org.apache.hadoop.mapreduce.RecordReader<Text,Text>

org.apache.hadoop.mapreduce.lib.input.SequenceFileAsTextRecordReader

所有已实现的接口:

Closeable, AutoCloseable

@InterfaceAudience.Public
@InterfaceStability.Stable
public class SequenceFileAsTextRecordReader
extends RecordReader<Text,Text>

This class converts the input keys and values to their String forms by calling toString() method. This class to SequenceFileAsTextInputFormat class is as LineRecordReader class to TextInputFormat class.

构造器概要

构造器

构造器和说明
SequenceFileAsTextRecordReader()

方法概要

方法

限定符和类型	方法和说明
void	close() Close the record reader.
Text	getCurrentKey() Get the current key
Text	getCurrentValue() Get the current value.
float	getProgress() The current progress of the record reader through its data.
void	initialize(InputSplit split, TaskAttemptContext context) Called once at initialization.
boolean	nextKeyValue() Read key/value pair in a line.

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

SequenceFileAsTextRecordReader

public SequenceFileAsTextRecordReader()
                               throws IOException

抛出:

IOException

方法详细资料

initialize

public void initialize(InputSplit split,
              TaskAttemptContext context)
                throws IOException,
                       InterruptedException

从类复制的说明: RecordReader

Called once at initialization.

指定者:

initialize 在类中 RecordReader<Text,Text>

参数:

split - the split that defines the range of records to read

context - the information about the task

抛出:

IOException

InterruptedException

getCurrentKey

public Text getCurrentKey()
                   throws IOException,
                          InterruptedException

从类复制的说明: RecordReader

Get the current key

指定者:

getCurrentKey 在类中 RecordReader<Text,Text>

返回:

the current key or null if there is no current key

抛出:

IOException

InterruptedException

getCurrentValue

public Text getCurrentValue()
                     throws IOException,
                            InterruptedException

从类复制的说明: RecordReader

Get the current value.

指定者:

getCurrentValue 在类中 RecordReader<Text,Text>

返回:

the object that was read

抛出:

IOException

InterruptedException

nextKeyValue

public boolean nextKeyValue()
                     throws IOException,
                            InterruptedException

Read key/value pair in a line.

指定者:

nextKeyValue 在类中 RecordReader<Text,Text>

返回:

true if a key/value pair was read

抛出:

IOException

InterruptedException

getProgress

public float getProgress()
                  throws IOException,
                         InterruptedException

从类复制的说明: RecordReader

The current progress of the record reader through its data.

指定者:

getProgress 在类中 RecordReader<Text,Text>

返回:

a number between 0.0 and 1.0 that is the fraction of the data read

抛出:

IOException

InterruptedException

close

public void close()
           throws IOException

从类复制的说明: RecordReader

Close the record reader.

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 RecordReader<Text,Text>

抛出:

IOException