Class SAXHandler

All Implemented Interfaces:
ContentHandler, DTDHandler, EntityResolver, ErrorHandler, DeclHandler, LexicalHandler

public class SAXHandler extends DefaultHandler implements LexicalHandler, DeclHandler, DTDHandler
A support class for SAXBuilder which listens for SAX events.

People overriding this class are cautioned to ensure that the implementation of the cleanUp() method resets to a virgin state. The cleanUp() method will be called when this SAXHandler is reset(), which may happen multiple times between parses. The cleanUp() method must ensure that there are no references remaining to any external instances.

Overriding of this class is permitted to allow for different handling of SAX events. Once you have created a subclass of this, you also need to create a custom implementation of SAXHandlerFactory to supply your instances to SAXBuilder

If the XMLReader producing the SAX Events supports a document Locator, then this instance will use the locator to supply the line and column data from the SAX locator to the JDOMFactory. Note: the SAX specification for the SAX Locator indicates that the line and column represent the position of the end of the SAX Event. For example, the line and column of the simple XML <root /> would be line 1, column 9.

Author:
Brett McLaughlin, Jason Hunter, Philip Nelson, Bradley S. Huffman, phil@triloggroup.com, Rolf Lear
See Also:
  • Constructor Details

    • SAXHandler

      public SAXHandler()
      This will create a new SAXHandler that listens to SAX events and creates a JDOM Document. The objects will be constructed using the default factory.
    • SAXHandler

      public SAXHandler(JDOMFactory factory)
      This will create a new SAXHandler that listens to SAX events and creates a JDOM Document. The objects will be constructed using the provided factory.
      Parameters:
      factory - JDOMFactory to be used for constructing objects
  • Method Details

    • resetSubCLass

      protected void resetSubCLass()
      Override this method if you are a subclasser, and you want to clear the state of your SAXHandler instance in preparation for a new parse.
    • reset

      public final void reset()
      Restore this SAXHandler to a clean state ready for another parse round. All internal variables are cleared to an initialized state, and then the resetSubClass() method is called to clear any methods that a subclass may need to have reset.
    • pushElement

      protected void pushElement(Element element)
      Pushes an element onto the tree under construction. Allows subclasses to put content under a dummy root element which is useful for building content that would otherwise be a non-well formed document.
      Parameters:
      element - root element under which content will be built
    • getDocument

      public Document getDocument()
      Returns the document. Should be called after parsing is complete.
      Returns:
      Document - Document that was built
    • getFactory

      public JDOMFactory getFactory()
      Returns the factory used for constructing objects.
      Returns:
      JDOMFactory - the factory used for constructing objects.
      See Also:
    • setExpandEntities

      public void setExpandEntities(boolean expand)
      This sets whether or not to expand entities during the build. A true means to expand entities as normal content. A false means to leave entities unexpanded as EntityRef objects. The default is true.
      Parameters:
      expand - boolean indicating whether entity expansion should occur.
    • getExpandEntities

      public boolean getExpandEntities()
      Returns whether or not entities will be expanded during the build.
      Returns:
      boolean - whether entity expansion will occur during build.
      See Also:
    • setIgnoringElementContentWhitespace

      public void setIgnoringElementContentWhitespace(boolean ignoringWhite)
      Specifies whether or not the parser should eliminate whitespace in element content (sometimes known as "ignorable whitespace") when building the document. Only whitespace which is contained within element content that has an element only content model will be eliminated (see XML Rec 3.2.1). For this setting to take effect requires that validation be turned on. The default value of this setting is false.
      Parameters:
      ignoringWhite - Whether to ignore ignorable whitespace
    • setIgnoringBoundaryWhitespace

      public void setIgnoringBoundaryWhitespace(boolean ignoringBoundaryWhite)
      Specifies whether or not the parser should eliminate text() nodes containing only whitespace when building the document. See SAXBuilder.setIgnoringBoundaryWhitespace(boolean).
      Parameters:
      ignoringBoundaryWhite - Whether to ignore only whitespace content
    • getIgnoringBoundaryWhitespace

      public boolean getIgnoringBoundaryWhitespace()
      Returns whether or not the parser will eliminate element content containing only whitespace.
      Returns:
      boolean - whether only whitespace content will be ignored during build.
      See Also:
    • getIgnoringElementContentWhitespace

      public boolean getIgnoringElementContentWhitespace()
      Returns whether or not the parser will eliminate whitespace in element content (sometimes known as "ignorable whitespace") when building the document.
      Returns:
      boolean - whether ignorable whitespace will be ignored during build.
      See Also:
    • startDocument

      public void startDocument()
      Specified by:
      startDocument in interface ContentHandler
      Overrides:
      startDocument in class DefaultHandler
    • externalEntityDecl

      public void externalEntityDecl(String name, String publicID, String systemID) throws SAXException
      This is called when the parser encounters an external entity declaration.
      Specified by:
      externalEntityDecl in interface DeclHandler
      Parameters:
      name - entity name
      publicID - public id
      systemID - system id
      Throws:
      SAXException - when things go wrong
    • attributeDecl

      public void attributeDecl(String eName, String aName, String type, String valueDefault, String value)
      This handles an attribute declaration in the internal subset.
      Specified by:
      attributeDecl in interface DeclHandler
      Parameters:
      eName - String element name of attribute
      aName - String attribute name
      type - String attribute type
      valueDefault - String default value of attribute
      value - String value of attribute
    • elementDecl

      public void elementDecl(String name, String model)
      Handle an element declaration in a DTD.
      Specified by:
      elementDecl in interface DeclHandler
      Parameters:
      name - String name of element
      model - String model of the element in DTD syntax
    • internalEntityDecl

      public void internalEntityDecl(String name, String value)
      Handle an internal entity declaration in a DTD.
      Specified by:
      internalEntityDecl in interface DeclHandler
      Parameters:
      name - String name of entity
      value - String value of the entity
    • processingInstruction

      public void processingInstruction(String target, String data) throws SAXException
      This will indicate that a processing instruction has been encountered. (The XML declaration is not a processing instruction and will not be reported.)
      Specified by:
      processingInstruction in interface ContentHandler
      Overrides:
      processingInstruction in class DefaultHandler
      Parameters:
      target - String target of PI
      data - String containing all data sent to the PI. This typically looks like one or more attribute value pairs.
      Throws:
      SAXException - when things go wrong
    • skippedEntity

      public void skippedEntity(String name) throws SAXException
      This indicates that an unresolvable entity reference has been encountered, normally because the external DTD subset has not been read.
      Specified by:
      skippedEntity in interface ContentHandler
      Overrides:
      skippedEntity in class DefaultHandler
      Parameters:
      name - String name of entity
      Throws:
      SAXException - when things go wrong
    • startPrefixMapping

      public void startPrefixMapping(String prefix, String uri) throws SAXException
      This will add the prefix mapping to the JDOM Document object.
      Specified by:
      startPrefixMapping in interface ContentHandler
      Overrides:
      startPrefixMapping in class DefaultHandler
      Parameters:
      prefix - String namespace prefix.
      uri - String namespace URI.
      Throws:
      SAXException
    • startElement

      public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException
      This reports the occurrence of an actual element. It will include the element's attributes, with the exception of XML vocabulary specific attributes, such as xmlns:[namespace prefix] and xsi:schemaLocation.
      Specified by:
      startElement in interface ContentHandler
      Overrides:
      startElement in class DefaultHandler
      Parameters:
      namespaceURI - String namespace URI this element is associated with, or an empty String
      localName - String name of element (with no namespace prefix, if one is present)
      qName - String XML 1.0 version of element name: [namespace prefix]:[localName]
      atts - Attributes list for this element
      Throws:
      SAXException - when things go wrong
    • characters

      public void characters(char[] ch, int start, int length) throws SAXException
      This will report character data (within an element).
      Specified by:
      characters in interface ContentHandler
      Overrides:
      characters in class DefaultHandler
      Parameters:
      ch - char[] character array with character data
      start - int index in array where data starts.
      length - int length of data.
      Throws:
      SAXException
    • ignorableWhitespace

      public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException
      Capture ignorable whitespace as text. If setIgnoringElementContentWhitespace(true) has been called then this method does nothing.
      Specified by:
      ignorableWhitespace in interface ContentHandler
      Overrides:
      ignorableWhitespace in class DefaultHandler
      Parameters:
      ch - [] - char array of ignorable whitespace
      start - int - starting position within array
      length - int - length of whitespace after start
      Throws:
      SAXException - when things go wrong
    • flushCharacters

      protected void flushCharacters() throws SAXException
      This will flush any characters from SAX character calls we've been buffering.
      Throws:
      SAXException - when things go wrong
    • flushCharacters

      protected void flushCharacters(String data) throws SAXException
      Flush the given string into the document. This is a protected method so subclassers can control text handling without knowledge of the internals of this class.
      Parameters:
      data - string to flush
      Throws:
      SAXException - if the state of the handler does not allow this.
    • endElement

      public void endElement(String namespaceURI, String localName, String qName) throws SAXException
      Indicates the end of an element (</[element name]>) is reached. Note that the parser does not distinguish between empty elements and non-empty elements, so this will occur uniformly.
      Specified by:
      endElement in interface ContentHandler
      Overrides:
      endElement in class DefaultHandler
      Parameters:
      namespaceURI - String URI of namespace this element is associated with
      localName - String name of element without prefix
      qName - String name of element in XML 1.0 form
      Throws:
      SAXException - when things go wrong
    • startDTD

      public void startDTD(String name, String publicID, String systemID) throws SAXException
      This will signify that a DTD is being parsed, and can be used to ensure that comments and other lexical structures in the DTD are not added to the JDOM Document object.
      Specified by:
      startDTD in interface LexicalHandler
      Parameters:
      name - String name of element listed in DTD
      publicID - String public ID of DTD
      systemID - String system ID of DTD
      Throws:
      SAXException
    • endDTD

      public void endDTD()
      This signifies that the reading of the DTD is complete.
      Specified by:
      endDTD in interface LexicalHandler
    • startEntity

      public void startEntity(String name) throws SAXException
      Specified by:
      startEntity in interface LexicalHandler
      Throws:
      SAXException
    • endEntity

      public void endEntity(String name) throws SAXException
      Specified by:
      endEntity in interface LexicalHandler
      Throws:
      SAXException
    • startCDATA

      public void startCDATA()
      Report a CDATA section
      Specified by:
      startCDATA in interface LexicalHandler
    • endCDATA

      public void endCDATA() throws SAXException
      Report a CDATA section
      Specified by:
      endCDATA in interface LexicalHandler
      Throws:
      SAXException
    • comment

      public void comment(char[] ch, int start, int length) throws SAXException
      This reports that a comments is parsed. If not in the DTD, this comment is added to the current JDOM Element, or the Document itself if at that level.
      Specified by:
      comment in interface LexicalHandler
      Parameters:
      ch - ch[] array of comment characters.
      start - int index to start reading from.
      length - int length of data.
      Throws:
      SAXException - if the state of the handler disallows this call
    • notationDecl

      public void notationDecl(String name, String publicID, String systemID) throws SAXException
      Handle the declaration of a Notation in a DTD
      Specified by:
      notationDecl in interface DTDHandler
      Overrides:
      notationDecl in class DefaultHandler
      Parameters:
      name - name of the notation
      publicID - the public ID of the notation
      systemID - the system ID of the notation
      Throws:
      SAXException
    • unparsedEntityDecl

      public void unparsedEntityDecl(String name, String publicID, String systemID, String notationName)
      Handler for unparsed entity declarations in the DTD
      Specified by:
      unparsedEntityDecl in interface DTDHandler
      Overrides:
      unparsedEntityDecl in class DefaultHandler
      Parameters:
      name - String of the unparsed entity decl
      publicID - String of the unparsed entity decl
      systemID - String of the unparsed entity decl
      notationName - String of the unparsed entity decl
    • getCurrentElement

      public Element getCurrentElement() throws SAXException
      Returns the being-parsed element.
      Returns:
      Element - element being built.
      Throws:
      SAXException - if the state of the handler disallows this call
    • setDocumentLocator

      public void setDocumentLocator(Locator locator)
      Receives an object for locating the origin of SAX document events. This method is invoked by the SAX parser.

      JDOMFactory implementations can use the getDocumentLocator() method to get access to the Locator during parse.

      Specified by:
      setDocumentLocator in interface ContentHandler
      Overrides:
      setDocumentLocator in class DefaultHandler
      Parameters:
      locator - Locator an object that can return the location of any SAX document event.
    • getDocumentLocator

      public Locator getDocumentLocator()
      Provides access to the Locator object provided by the SAX parser.
      Returns:
      Locator an object that can return the location of any SAX document event.