de.gerdiproject.harvest.etls.extractors

Class AbstractIteratorExtractor<T>

java.lang.Object

de.gerdiproject.harvest.etls.extractors.AbstractIteratorExtractor<T>

Type Parameters:

T - the type of objects that are extracted

All Implemented Interfaces:

IExtractor<Iterator<T>>

Direct Known Subclasses:

JsonArrayExtractor

public abstract class AbstractIteratorExtractor<T>
extends Object
implements IExtractor<Iterator<T>>

This IExtractor can extract an Iterator in order to be able to iterate lists or similar constructs.

Author:

Robin Weiss

Field Summary

Fields

Modifier and Type	Field and Description
protected int	endIndex
protected int	startIndex

Constructor Summary

Constructors

Constructor and Description
AbstractIteratorExtractor()

Method Summary

Modifier and Type	Method and Description
Iterator<T>	extract() Extracts elements from a source repository.
protected abstract Iterator<T>	extractAll() This method extracts everything there is to extract.
void	init(AbstractETL<?,?> etl) Initializes the extractor for a new harvest.
int	size() Returns the number of extractable documents, or -1 if they cannot be estimated.

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.gerdiproject.harvest.etls.extractors.IExtractor

clear, getUniqueVersionString

Field Detail

startIndex

protected int startIndex

endIndex

protected int endIndex

Constructor Detail

AbstractIteratorExtractor

public AbstractIteratorExtractor()

Method Detail

init

public void init(AbstractETL<?,?> etl)

Description copied from interface: IExtractor

Initializes the extractor for a new harvest.

Specified by:

init in interface IExtractor<Iterator<T>>

Parameters:

etl - the AbstractETL to which the extractor belongs

extractAll

protected abstract Iterator<T> extractAll()
                                   throws ExtractorException

This method extracts everything there is to extract.

Returns:

an Iterator over the complete data

Throws:

ExtractorException - thrown when the extraction fails

extract

public Iterator<T> extract()
                    throws ExtractorException

Description copied from interface: IExtractor

Extracts elements from a source repository.

Specified by:

extract in interface IExtractor<Iterator<T>>

Returns:

an object that is to be transformed

Throws:

ExtractorException - thrown when the extraction fails

size

public int size()

Description copied from interface: IExtractor

Returns the number of extractable documents, or -1 if they cannot be estimated.

Specified by:

size in interface IExtractor<Iterator<T>>

Returns:

the number of extractable documents, or -1