edu.umd.cloud9.collection

Class XMLInputFormat.XMLRecordReader

java.lang.Object

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

edu.umd.cloud9.collection.XMLInputFormat.XMLRecordReader

All Implemented Interfaces:

Closeable, AutoCloseable

Enclosing class:

XMLInputFormat

public static class XMLInputFormat.XMLRecordReader
extends org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text>

Simple RecordReader for XML documents (org.apache.hadoop.mapreduce API). Recognizes begin-of-document and end-of-document tags only: everything between those delimiting tags is returned in a Text object.

Author:

Jimmy Lin

Constructor Summary

Constructors

Constructor and Description
XMLInputFormat.XMLRecordReader()

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the record reader.
org.apache.hadoop.io.LongWritable	getCurrentKey() Returns the current key.
org.apache.hadoop.io.Text	getCurrentValue() Returns the current value.
float	getProgress() The current progress of the record reader through its data.
void	initialize(org.apache.hadoop.mapreduce.InputSplit input, org.apache.hadoop.mapreduce.TaskAttemptContext context) Called once at initialization.
boolean	nextKeyValue() Read the next key, value pair.

Methods inherited from class java.lang.Object

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

Constructor Detail

XMLInputFormat.XMLRecordReader

public XMLInputFormat.XMLRecordReader()

Method Detail

initialize

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

Called once at initialization.

Specified by:

initialize in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text>

Parameters:

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

context - the information about the task

Throws:

IOException

InterruptedException

nextKeyValue

public boolean nextKeyValue()
                     throws IOException,
                            InterruptedException

Read the next key, value pair.

Specified by:

nextKeyValue in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text>

Returns:

true if a key/value pair was read

Throws:

IOException

InterruptedException

getCurrentKey

public org.apache.hadoop.io.LongWritable getCurrentKey()
                                                throws IOException,
                                                       InterruptedException

Returns the current key.

Specified by:

getCurrentKey in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text>

Returns:

the current key or null if there is no current key

Throws:

IOException

InterruptedException

getCurrentValue

public org.apache.hadoop.io.Text getCurrentValue()
                                          throws IOException,
                                                 InterruptedException

Returns the current value.

Specified by:

getCurrentValue in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text>

Returns:

current value

Throws:

IOException

InterruptedException

close

public void close()
           throws IOException

Closes the record reader.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text>

Throws:

IOException

getProgress

public float getProgress()
                  throws IOException

The current progress of the record reader through its data.

Specified by:

getProgress in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.LongWritable,org.apache.hadoop.io.Text>

Returns:

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

Throws:

IOException

InterruptedException