org.dspace.app.xmlui.objectmanager

Class SAXFilter

java.lang.Object

org.dspace.app.xmlui.objectmanager.SAXFilter

All Implemented Interfaces:

ContentHandler, LexicalHandler

public class SAXFilter
extends Object
implements ContentHandler, LexicalHandler

This is a Swiss army like SAX Filter, its purpose is to filter out undesirable SAX events from the stream. The primary application of this is for inserting SAX fragment into an existing SAX pipeline, under this scenario you would not want new startDocument or endDocument events interfering with the existing pipeline thus this class can filter those out. The Swiss army part comes in because it's configurable. Instead of defining a static set of events that are filled out by default all events are filled out and must be turned on to allow each type individually. Primarily you can filter events based upon their type, i.e. start/end elements or start/end documents. However there is one special control, and that is to only allow elements below a minimum level. .

Author:

Scott Phillips

Constructor Summary

Constructors

Constructor and Description
SAXFilter(ContentHandler contentHandler, LexicalHandler lexicalHandler, org.xml.sax.helpers.NamespaceSupport namespaces) Construct a new SAXFilter such that the allowed events will be routed to the corresponding content and lexical handlers.

Method Summary

Methods

Modifier and Type	Method and Description
SAXFilter	allowCDATA() Allow CDATA events
SAXFilter	allowCharacters() Allow character events
SAXFilter	allowComments() Allow comment events
SAXFilter	allowDocumentLocators() Allow document locator events
SAXFilter	allowDocuments() Allow start/end document events
SAXFilter	allowDTDs() Allow DTD events
SAXFilter	allowElements() allow start/end element events
SAXFilter	allowElements(int minimumElementLevel) Allow start/end element events.
SAXFilter	allowEntities() Allow XML entities events
SAXFilter	allowIgnorableWhitespace() Allow ignorable whitespace events
SAXFilter	allowPrefixMappings() allow start/end prefix mapping events
SAXFilter	allowProcessingInstructions() Allow processing instruction events
SAXFilter	allowSkippedEntities() Allow start / end events for skipped entities
void	characters(char[] ch, int start, int length) Character content.
void	comment(char[] ch, int start, int length) XML comment.
void	endCDATA() End of character data.
void	endDocument() End of the document.
void	endDTD() End of a DTD declaration.
void	endElement(String uri, String localName, String qName) End of an element.
void	endEntity(String name) End of an entity.
void	endPrefixMapping(String prefix) End of a prefix mapping.
void	ignorableWhitespace(char[] ch, int start, int length) Ignorable whitespace is recognized.
void	processingInstruction(String target, String data) A processing instruction was parsed.
SAXFilter	setDefaultNamespace(String uri) Add a default namespace is none is provided.
void	setDocumentLocator(Locator locator) Supply a callback object for location awareness.
void	skippedEntity(String name) Recognize a skipped entity.
void	startCDATA() Start of character data.
void	startDocument() Start of the document.
void	startDTD(String name, String publicId, String systemId) Start of a DTD declaration.
void	startElement(String uri, String localName, String qName, Attributes atts) Start of an element.
void	startEntity(String name) Start of an entity.
void	startPrefixMapping(String prefix, String uri) A namespace prefix is declared.

Methods inherited from class java.lang.Object

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

Constructor Detail

SAXFilter

public SAXFilter(ContentHandler contentHandler,
         LexicalHandler lexicalHandler,
         org.xml.sax.helpers.NamespaceSupport namespaces)

Construct a new SAXFilter such that the allowed events will be routed to the corresponding content and lexical handlers.

Parameters:

contentHandler - The SAX content handler.

lexicalHandler - The SAX lexical handler.

namespaces - Namespace support which records what prefixes have been defined.

Method Detail

allowDocuments

public SAXFilter allowDocuments()

Allow start/end document events

Returns:

this instance.

allowDocumentLocators

public SAXFilter allowDocumentLocators()

Allow document locator events

Returns:

this instance.

allowProcessingInstructions

public SAXFilter allowProcessingInstructions()

Allow processing instruction events

Returns:

this instance.

allowPrefixMappings

public SAXFilter allowPrefixMappings()

allow start/end prefix mapping events

Returns:

this instance.

allowElements

public SAXFilter allowElements()

allow start/end element events

Returns:

this instance.

allowElements

public SAXFilter allowElements(int minimumElementLevel)

Allow start/end element events. However only allow those start / end events if they are below the given XML level. I.e. each nested element is a new level.

Parameters:

minimumElementLevel - the minimum level required.

Returns:

this SAXFilter instance.

allowIgnorableWhitespace

public SAXFilter allowIgnorableWhitespace()

Allow ignorable whitespace events

Returns:

this instance.

allowSkippedEntities

public SAXFilter allowSkippedEntities()

Allow start / end events for skipped entities

Returns:

this instance.

allowCharacters

public SAXFilter allowCharacters()

Allow character events

Returns:

this instance.

allowDTDs

public SAXFilter allowDTDs()

Allow DTD events

Returns:

this instance.

allowEntities

public SAXFilter allowEntities()

Allow XML entities events

Returns:

this instance.

allowCDATA

public SAXFilter allowCDATA()

Allow CDATA events

Returns:

this instance.

allowComments

public SAXFilter allowComments()

Allow comment events

Returns:

this instance.

setDefaultNamespace

public SAXFilter setDefaultNamespace(String uri)

Add a default namespace is none is provided. The namespace should have already been declared (add added to the namespace support object

Parameters:

uri - the default namespace uri.

Returns:

this instance.

startDocument

public void startDocument()
                   throws SAXException

Start of the document.

Specified by:

startDocument in interface ContentHandler

Throws:

SAXException - passed through.

endDocument

public void endDocument()
                 throws SAXException

End of the document.

Specified by:

endDocument in interface ContentHandler

Throws:

SAXException - passed through.

setDocumentLocator

public void setDocumentLocator(Locator locator)

Supply a callback object for location awareness.

Specified by:

setDocumentLocator in interface ContentHandler

Parameters:

locator - the new locator.

processingInstruction

public void processingInstruction(String target,
                         String data)
                           throws SAXException

A processing instruction was parsed.

Specified by:

processingInstruction in interface ContentHandler

Parameters:

target - the processing instruction target.

data - from the processing instruction.

Throws:

SAXException - passed through.

startPrefixMapping

public void startPrefixMapping(String prefix,
                      String uri)
                        throws SAXException

A namespace prefix is declared.

Specified by:

startPrefixMapping in interface ContentHandler

Parameters:

prefix - a tag prefix.

uri - namespace indicated by the prefix.

Throws:

SAXException - passed through.

endPrefixMapping

public void endPrefixMapping(String prefix)
                      throws SAXException

End of a prefix mapping.

Specified by:

endPrefixMapping in interface ContentHandler

Parameters:

prefix - the name of the mapping.

Throws:

SAXException - passed through.

startElement

public void startElement(String uri,
                String localName,
                String qName,
                Attributes atts)
                  throws SAXException

Start of an element.

Specified by:

startElement in interface ContentHandler

Parameters:

uri - namespace of the element.

localName - local name of the element.

qName - qualified name of the element.

atts - attributes of this instance of the element.

Throws:

SAXException - passed through.

endElement

public void endElement(String uri,
              String localName,
              String qName)
                throws SAXException

End of an element.

Specified by:

endElement in interface ContentHandler

Parameters:

uri - namespace of the element.

localName - local name of the element.

qName - qualified name of the element.

Throws:

SAXException - passed through.

ignorableWhitespace

public void ignorableWhitespace(char[] ch,
                       int start,
                       int length)
                         throws SAXException

Ignorable whitespace is recognized.

Specified by:

ignorableWhitespace in interface ContentHandler

Parameters:

ch - content of the whitespace.

start - starting position.

length - length of the whitespace.

Throws:

SAXException - passed through.

skippedEntity

public void skippedEntity(String name)
                   throws SAXException

Recognize a skipped entity.

Specified by:

skippedEntity in interface ContentHandler

Parameters:

name - name of the entity.

Throws:

SAXException - passed through.

characters

public void characters(char[] ch,
              int start,
              int length)
                throws SAXException

Character content.

Specified by:

characters in interface ContentHandler

Parameters:

ch - content characters.

start - starting position.

length - length of content.

Throws:

SAXException - passed through.

startDTD

public void startDTD(String name,
            String publicId,
            String systemId)
              throws SAXException

Start of a DTD declaration.

Specified by:

startDTD in interface LexicalHandler

Parameters:

name - of the DTD.

publicId - public identifier for the DTD.

systemId - system identifier for the DTD.

Throws:

SAXException - passed through.

endDTD

public void endDTD()
            throws SAXException

End of a DTD declaration.

Specified by:

endDTD in interface LexicalHandler

Throws:

SAXException - passed through.

startEntity

public void startEntity(String name)
                 throws SAXException

Start of an entity.

Specified by:

startEntity in interface LexicalHandler

Parameters:

name - of the entity.

Throws:

SAXException - passed through.

endEntity

public void endEntity(String name)
               throws SAXException

End of an entity.

Specified by:

endEntity in interface LexicalHandler

Parameters:

name - of the entity.

Throws:

SAXException - passed through

startCDATA

public void startCDATA()
                throws SAXException

Start of character data.

Specified by:

startCDATA in interface LexicalHandler

Throws:

SAXException - passed through.

endCDATA

public void endCDATA()
              throws SAXException

End of character data.

Specified by:

endCDATA in interface LexicalHandler

Throws:

SAXException - passed through.

comment

public void comment(char[] ch,
           int start,
           int length)
             throws SAXException

XML comment.

Specified by:

comment in interface LexicalHandler

Parameters:

ch - content of the comment.

start - starting position.

length - length of the comment.

Throws:

SAXException - passed through.