com.norconex.importer.handler

Class AbstractImporterHandler

java.lang.Object

com.norconex.importer.handler.AbstractImporterHandler

All Implemented Interfaces:

IXMLConfigurable

Direct Known Subclasses:

AbstractDocumentFilter, AbstractDocumentSplitter, AbstractDocumentTagger, AbstractDocumentTransformer

public abstract class AbstractImporterHandler
extends Object
implements IXMLConfigurable

Base class for handlers applying only to certain type of documents by providing a way to restrict applicable documents based on a metadata field value, where the value matches a regular expression. For instance, to apply a handler only to text documents, you can use the following:

   myHandler.setRestriction("document.contentType", "^text/.*$");
 

Subclasses inherit this IXMLConfigurable configuration:

  <restrictTo caseSensitive="[false|true]"
          field="(name of metadata field name to match)">
      (regular expression of value to match)
  </restrictTo>
  <!-- multiple "restrictTo" tags allowed (only one needs to match) -->
 

Subclasses must test if a document is accepted using the isApplicable(String, ImporterMetadata, boolean) method.

Subclasses can safely be used as either pre-parse or post-parse handlers.

Since:

2.0.0

Author:

Pascal Essiembre

Constructor Summary

Constructors

Constructor and Description
AbstractImporterHandler(String xmltag)

Method Summary

Modifier and Type	Method and Description
void	addRestriction(PropertyMatcher... restriction) Adds one or more restrictions this handler should be restricted to.
void	addRestriction(String field, String regex, boolean caseSensitive) Adds a restriction this handler should be restricted to.
void	addRestrictions(List<PropertyMatcher> restrictions) Adds restrictions this handler should be restricted to.
void	clearRestrictions() Clears all restrictions.
protected String	detectCharsetIfBlank(String charset, String reference, InputStream document, ImporterMetadata metadata, boolean parsed) Convenience method for handlers that need to detect an input encoding if the explicitly provided encoding is blank.
boolean	equals(Object other)
List<PropertyMatcher>	getRestrictions() Gets all restrictions
int	hashCode()
protected boolean	isApplicable(String reference, ImporterMetadata metadata, boolean parsed) Class to invoke by subclasses to find out if this handler should be rejected or not based on the metadata restriction provided.
void	loadFromXML(Reader in)
protected abstract void	loadHandlerFromXML(org.apache.commons.configuration.XMLConfiguration xml) Loads configuration settings specific to the implementing class.
boolean	removeRestriction(PropertyMatcher restriction) Removes a restriction.
int	removeRestriction(String field) Removes all restrictions on a given field.
protected abstract void	saveHandlerToXML(EnhancedXMLStreamWriter writer) Saves configuration settings specific to the implementing class.
void	saveToXML(Writer out)
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractImporterHandler

public AbstractImporterHandler(String xmltag)

Method Detail

addRestriction

public void addRestriction(String field,
                           String regex,
                           boolean caseSensitive)

Adds a restriction this handler should be restricted to.

Parameters:

field - metadata property/field

regex - regular expression

caseSensitive - whether regular expression should be case sensitive

addRestriction

public void addRestriction(PropertyMatcher... restriction)

Adds one or more restrictions this handler should be restricted to.

Parameters:

restriction - the restriction

Since:

2.4.0

addRestrictions

public void addRestrictions(List<PropertyMatcher> restrictions)

Adds restrictions this handler should be restricted to.

Parameters:

restrictions - the restrictions

Since:

2.4.0

removeRestriction

public int removeRestriction(String field)

Removes all restrictions on a given field.

Parameters:

field - the field to remove restrictions on

Returns:

how many elements were removed

Since:

2.4.0

removeRestriction

public boolean removeRestriction(PropertyMatcher restriction)

Removes a restriction.

Parameters:

restriction - the restriction to remove

Returns:

true if this handler contained the restriction

Since:

2.4.0

clearRestrictions

public void clearRestrictions()

Clears all restrictions.

Since:

2.4.0

getRestrictions

public List<PropertyMatcher> getRestrictions()

Gets all restrictions

Returns:

the restrictions

Since:

2.4.0

isApplicable

protected final boolean isApplicable(String reference,
                                     ImporterMetadata metadata,
                                     boolean parsed)

Class to invoke by subclasses to find out if this handler should be rejected or not based on the metadata restriction provided.

Parameters:

reference - document reference

metadata - document metadata.

parsed - if the document was parsed (i.e. imported) already

Returns:

true if this handler is applicable to the document

detectCharsetIfBlank

protected final String detectCharsetIfBlank(String charset,
                                            String reference,
                                            InputStream document,
                                            ImporterMetadata metadata,
                                            boolean parsed)

Convenience method for handlers that need to detect an input encoding if the explicitly provided encoding is blank. Detection is only attempted if parsing has not occurred (since parsing converts everything to UTF-8 already).

Parameters:

charset - the character encoding to test if blank

reference - the reference of the document to detect charset on

document - the document to detect charset on

metadata - the document metadata to check for declared encoding

parsed - whether the document has already been parsed or not.

Returns:

detected and clean encoding.

loadFromXML

public final void loadFromXML(Reader in)
                       throws IOException

Specified by:

loadFromXML in interface IXMLConfigurable

Throws:

IOException

loadHandlerFromXML

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

Loads configuration settings specific to the implementing class.

Parameters:

xml - xml configuration

Throws:

IOException - could not load from XML

saveToXML

public final void saveToXML(Writer out)
                     throws IOException

Specified by:

saveToXML in interface IXMLConfigurable

Throws:

IOException

saveHandlerToXML

protected abstract void saveHandlerToXML(EnhancedXMLStreamWriter writer)
                                  throws XMLStreamException

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.

Parameters:

writer - the xml writer

Throws:

XMLStreamException - could not save to XML

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object