com.norconex.importer.handler.filter

Class AbstractDocumentFilter

java.lang.Object

com.norconex.importer.handler.AbstractImporterHandler

com.norconex.importer.handler.filter.AbstractDocumentFilter

All Implemented Interfaces:

IXMLConfigurable, IDocumentFilter, IOnMatchFilter, IImporterHandler

Direct Known Subclasses:

AbstractCharStreamFilter, DateMetadataFilter, DOMContentFilter, EmptyMetadataFilter, NumericMetadataFilter, RegexMetadataFilter, RegexReferenceFilter

public abstract class AbstractDocumentFilter
extends AbstractImporterHandler
implements IDocumentFilter, IOnMatchFilter

Base class for document filters. Subclasses can be set an attribute called "onMatch". The logic whether to include or exclude a document upon matching it is handled by this class. Subclasses only need to focus on whether the document gets matched or not by implementing the isDocumentMatched(String, InputStream, ImporterMetadata, boolean) method.

Inclusion/exclusion logic:

The logic for accepting or rejecting documents when a subclass condition is met ("matches") is as follow:

Matches?	On match	Expected behavior
yes	exclude	Document is rejected.
yes	include	Document is accepted.
no	exclude	Document is accepted.
no	include	Document is accepted if it was accepted by at least one filter with onMatch="include". If no other one exists or if none matched, the document is rejected.

When multiple filters are defined and a combination of both "include" and "exclude" are possible, the "exclude" will always take precedence. In other words, it only take one matching "exclude" to reject a document, not matter how many matching "include" were triggered.

XML configuration usage:

Subclasses inherit this IXMLConfigurable configuration:

  <!-- main tag supports onMatch="[include|exclude]" attribute -->
  <restrictTo caseSensitive="[false|true]"
          field="(name of header/metadata field name to match)">
      (regular expression of value to match)
  </restrictTo>
  <!-- multiple "restrictTo" tags allowed (only one needs to match) -->
 

Since:

2.0.0

Author:

Pascal Essiembre

See Also:

AbstractOnMatchFilter

Constructor Summary

Constructors

Constructor and Description
AbstractDocumentFilter()

Method Summary

Modifier and Type	Method and Description
boolean	acceptDocument(String reference, InputStream input, ImporterMetadata metadata, boolean parsed) Whether to accepts a document.
boolean	equals(Object other)
OnMatch	getOnMatch() Gets the the on match action (exclude or include).
int	hashCode()
protected abstract boolean	isDocumentMatched(String reference, InputStream input, ImporterMetadata metadata, boolean parsed)
protected abstract void	loadFilterFromXML(org.apache.commons.configuration.XMLConfiguration xml)
protected void	loadHandlerFromXML(org.apache.commons.configuration.XMLConfiguration xml) Loads configuration settings specific to the implementing class.
protected abstract void	saveFilterToXML(EnhancedXMLStreamWriter writer)
protected void	saveHandlerToXML(EnhancedXMLStreamWriter writer) Saves configuration settings specific to the implementing class.
void	setOnMatch(OnMatch onMatch)
String	toString()

Methods inherited from class com.norconex.importer.handler.AbstractImporterHandler

addRestriction, addRestriction, addRestrictions, clearRestrictions, detectCharsetIfBlank, getRestrictions, isApplicable, loadFromXML, removeRestriction, removeRestriction, saveToXML

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

AbstractDocumentFilter

public AbstractDocumentFilter()

Method Detail

getOnMatch

public OnMatch getOnMatch()

Description copied from interface: IOnMatchFilter

Gets the the on match action (exclude or include).

Specified by:

getOnMatch in interface IOnMatchFilter

Returns:

on match (exclude or include)

setOnMatch

public final void setOnMatch(OnMatch onMatch)

acceptDocument

public boolean acceptDocument(String reference,
                              InputStream input,
                              ImporterMetadata metadata,
                              boolean parsed)
                       throws ImporterHandlerException

Description copied from interface: IDocumentFilter

Whether to accepts a document.

Specified by:

acceptDocument in interface IDocumentFilter

Parameters:

reference - document reference

input - the document to evaluate

metadata - document metadata

parsed - whether the document has been parsed already or not (a parsed document should normally be text-based)

Returns:

true if document is accepted

Throws:

ImporterHandlerException - problem reading the document

isDocumentMatched

protected abstract boolean isDocumentMatched(String reference,
                                             InputStream input,
                                             ImporterMetadata metadata,
                                             boolean parsed)
                                      throws ImporterHandlerException

Throws:

ImporterHandlerException

saveHandlerToXML

protected final void saveHandlerToXML(EnhancedXMLStreamWriter writer)
                               throws XMLStreamException

Description copied from class: AbstractImporterHandler

Saves configuration settings specific to the implementing class. The parent tag along with the "class" attribute are already written. Implementors must not close the writer.

Specified by:

saveHandlerToXML in class AbstractImporterHandler

Parameters:

writer - the xml writer

Throws:

XMLStreamException - could not save to XML

saveFilterToXML

protected abstract void saveFilterToXML(EnhancedXMLStreamWriter writer)
                                 throws XMLStreamException

Throws:

XMLStreamException

loadHandlerFromXML

protected final void loadHandlerFromXML(org.apache.commons.configuration.XMLConfiguration xml)
                                 throws IOException

Description copied from class: AbstractImporterHandler

Loads configuration settings specific to the implementing class.

Specified by:

loadHandlerFromXML in class AbstractImporterHandler

Parameters:

xml - xml configuration

Throws:

IOException - could not load from XML

loadFilterFromXML

protected abstract void loadFilterFromXML(org.apache.commons.configuration.XMLConfiguration xml)
                                   throws IOException

Throws:

IOException

toString

public String toString()

Overrides:

toString in class AbstractImporterHandler

equals

public boolean equals(Object other)

Overrides:

equals in class AbstractImporterHandler

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractImporterHandler