de.gerdiproject.harvest.etls.transformers

Class AbstractIteratorTransformer<T,S>

java.lang.Object

de.gerdiproject.harvest.etls.transformers.AbstractIteratorTransformer<T,S>

Type Parameters:

T - the type of objects that are to be transformed

S - the resulting type of the transformed objects

All Implemented Interfaces:

ITransformer<Iterator<T>,Iterator<S>>

public abstract class AbstractIteratorTransformer<T,S>
extends Object
implements ITransformer<Iterator<T>,Iterator<S>>

This transformer can transform multiple documents.

Author:

Robin Weiss

Constructor Summary

Constructors

Constructor and Description
AbstractIteratorTransformer()

Method Summary

Modifier and Type	Method and Description
void	clear() Closes potentially open readers/writers and finishes the Transformation process if it is still ongoing.
void	init(AbstractETL<?,?> etl) Initializes the transformer for a new harvest.
Iterator<S>	transform(Iterator<T> elements) Transforms an extracted element to a document that can be loaded.
protected abstract S	transformElement(T source) Transforms a single element.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractIteratorTransformer

public AbstractIteratorTransformer()

Method Detail

init

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

Description copied from interface: ITransformer

Initializes the transformer for a new harvest.

Specified by:

init in interface ITransformer<Iterator<T>,Iterator<S>>

Parameters:

etl - the AbstractETL to which the transformer belongs

transformElement

protected abstract S transformElement(T source)
                               throws TransformerException

Transforms a single element.

Parameters:

source - a single element

Returns:

a transformed document

Throws:

TransformerException - thrown when an element cannot be transformed

transform

public Iterator<S> transform(Iterator<T> elements)
                      throws TransformerException

Description copied from interface: ITransformer

Transforms an extracted element to a document that can be loaded.

Specified by:

transform in interface ITransformer<Iterator<T>,Iterator<S>>

Parameters:

elements - an extracted element

Returns:

a document that can be loaded

Throws:

TransformerException - thrown when an element cannot be transformed

clear

public void clear()

Description copied from interface: ITransformer

Closes potentially open readers/writers and finishes the Transformation process if it is still ongoing.

Specified by:

clear in interface ITransformer<Iterator<T>,Iterator<S>>