org.apache.nutch.parse.html
Class DOMBuilder

java.lang.Object
  org.apache.nutch.parse.html.DOMBuilder

All Implemented Interfaces:

ContentHandler, LexicalHandler

public class DOMBuilder
extends Object
implements ContentHandler, LexicalHandler

This class takes SAX events (in addition to some extra events that SAX doesn't handle yet) and adds the result to a document or document fragment.

Field Summary

protected Node	m_currentNode Current node
Document	m_doc Root document
DocumentFragment	m_docFrag First node of document fragment or null if not a DocumentFragment
protected Stack	m_elemStack Vector of element nodes
protected boolean	m_inCData Flag indicating that we are processing a CData section

Constructor Summary

DOMBuilder(Document doc)
DOMBuilder instance constructor...

DOMBuilder(Document doc, DocumentFragment docFrag)
DOMBuilder instance constructor...

DOMBuilder(Document doc, Node node)
DOMBuilder instance constructor...

Method Summary

protected void	append(Node newNode) Append a node to the current container.
void	cdata(char[] ch, int start, int length) Receive notification of cdata.
void	characters(char[] ch, int start, int length) Receive notification of character data.
void	charactersRaw(char[] ch, int start, int length) If available, when the disable-output-escaping attribute is used, output raw text without escaping.
void	comment(char[] ch, int start, int length) Report an XML comment anywhere in the document.
void	endCDATA() Report the end of a CDATA section.
void	endDocument() Receive notification of the end of a document.
void	endDTD() Report the end of DTD declarations.
void	endElement(String ns, String localName, String name) Receive notification of the end of an element.
void	endEntity(String name) Report the end of an entity.
void	endPrefixMapping(String prefix) End the scope of a prefix-URI mapping.
void	entityReference(String name) Receive notivication of a entityReference.
Node	getCurrentNode() Get the node currently being processed.
Node	getRootNode() Get the root node of the DOM being created.
Writer	getWriter() Return null since there is no Writer for this class.
void	ignorableWhitespace(char[] ch, int start, int length) Receive notification of ignorable whitespace in element content.
void	processingInstruction(String target, String data) Receive notification of a processing instruction.
void	setDocumentLocator(Locator locator) Receive an object for locating the origin of SAX document events.
void	setIDAttribute(String id, Element elem) Set an ID string to node association in the ID table.
void	skippedEntity(String name) Receive notification of a skipped entity.
void	startCDATA() Report the start of a CDATA section.
void	startDocument() Receive notification of the beginning of a document.
void	startDTD(String name, String publicId, String systemId) Report the start of DTD declarations, if any.
void	startElement(String ns, String localName, String name, Attributes atts) Receive notification of the beginning of an element.
void	startEntity(String name) Report the beginning of an entity.
void	startPrefixMapping(String prefix, String uri) Begin the scope of a prefix-URI Namespace mapping.

Methods inherited from class java.lang.Object

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

Field Detail

m_doc

public Document m_doc

Root document

m_currentNode

protected Node m_currentNode

Current node

m_docFrag

public DocumentFragment m_docFrag

First node of document fragment or null if not a DocumentFragment

m_elemStack

protected Stack m_elemStack

Vector of element nodes

m_inCData

protected boolean m_inCData

Flag indicating that we are processing a CData section

Constructor Detail

DOMBuilder

public DOMBuilder(Document doc,
                  Node node)

DOMBuilder instance constructor... it will add the DOM nodes to the document fragment.

Parameters:

doc - Root document

node - Current node

DOMBuilder

public DOMBuilder(Document doc,
                  DocumentFragment docFrag)

DOMBuilder instance constructor... it will add the DOM nodes to the document fragment.

Parameters:

doc - Root document

docFrag - Document fragment

DOMBuilder

public DOMBuilder(Document doc)

DOMBuilder instance constructor... it will add the DOM nodes to the document.

Parameters:

doc - Root document

Method Detail

getRootNode

public Node getRootNode()

Get the root node of the DOM being created. This is either a Document or a DocumentFragment.

Returns:

The root document or document fragment if not null

getCurrentNode

public Node getCurrentNode()

Get the node currently being processed.

Returns:

the current node being processed

getWriter

public Writer getWriter()

Return null since there is no Writer for this class.

Returns:

null

append

protected void append(Node newNode)
               throws SAXException

Append a node to the current container.

Parameters:

newNode - New node to append

Throws:

SAXException

setDocumentLocator

public void setDocumentLocator(Locator locator)

Receive an object for locating the origin of SAX document events.

SAX parsers are strongly encouraged (though not absolutely required) to supply a locator: if it does so, it must supply the locator to the application by invoking this method before invoking any of the other methods in the ContentHandler interface.

The locator allows the application to determine the end position of any document-related event, even if the parser is not reporting an error. Typically, the application will use this information for reporting its own errors (such as character content that does not match an application's business rules). The information returned by the locator is probably not sufficient for use with a search engine.

Note that the locator will return correct information only during the invocation of the events in this interface. The application should not attempt to use it at any other time.

Specified by:

setDocumentLocator in interface ContentHandler

Parameters:

locator - An object that can return the location of any SAX document event.

See Also:

Locator

startDocument

public void startDocument()
                   throws SAXException

Receive notification of the beginning of a document.

The SAX parser will invoke this method only once, before any other methods in this interface or in DTDHandler (except for setDocumentLocator).

Specified by:

startDocument in interface ContentHandler

Throws:

SAXException

endDocument

public void endDocument()
                 throws SAXException

Receive notification of the end of a document.

The SAX parser will invoke this method only once, and it will be the last method invoked during the parse. The parser shall not invoke this method until it has either abandoned parsing (because of an unrecoverable error) or reached the end of input.

Specified by:

endDocument in interface ContentHandler

Throws:

SAXException

startElement

public void startElement(String ns,
                         String localName,
                         String name,
                         Attributes atts)
                  throws SAXException

Receive notification of the beginning of an element.

The Parser will invoke this method at the beginning of every element in the XML document; there will be a corresponding endElement() event for every startElement() event (even when the element is empty). All of the element's content will be reported, in order, before the corresponding endElement() event.

If the element name has a namespace prefix, the prefix will still be attached. Note that the attribute list provided will contain only attributes with explicit values (specified or defaulted): #IMPLIED attributes will be omitted.

Specified by:

startElement in interface ContentHandler

Parameters:

ns - The namespace of the node

localName - The local part of the qualified name

name - The element name.

atts - The attributes attached to the element, if any.

Throws:

SAXException

See Also:

endElement(java.lang.String, java.lang.String, java.lang.String), Attributes

endElement

public void endElement(String ns,
                       String localName,
                       String name)
                throws SAXException

Receive notification of the end of an element.

The SAX parser will invoke this method at the end of every element in the XML document; there will be a corresponding startElement() event for every endElement() event (even when the element is empty).

If the element name has a namespace prefix, the prefix will still be attached to the name.

Specified by:

endElement in interface ContentHandler

Parameters:

ns - the namespace of the element

localName - The local part of the qualified name of the element

name - The element name

Throws:

SAXException

setIDAttribute

public void setIDAttribute(String id,
                           Element elem)

Set an ID string to node association in the ID table.

Parameters:

id - The ID string.

elem - The associated ID.

characters

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

Receive notification of character data.

The Parser will call this method to report each chunk of character data. SAX parsers may return all contiguous character data in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity, so that the Locator provides useful information.

The application must not attempt to read from the array outside of the specified range.

Note that some parsers will report whitespace using the ignorableWhitespace() method rather than this one (validating parsers must do so).

Specified by:

characters in interface ContentHandler

Parameters:

ch - The characters from the XML document.

start - The start position in the array.

length - The number of characters to read from the array.

Throws:

SAXException

See Also:

ignorableWhitespace(char[], int, int), Locator

charactersRaw

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

If available, when the disable-output-escaping attribute is used, output raw text without escaping. A PI will be inserted in front of the node with the name "lotusxsl-next-is-raw" and a value of "formatter-to-dom".

Parameters:

ch - Array containing the characters

start - Index to start of characters in the array

length - Number of characters in the array

Throws:

SAXException

startEntity

public void startEntity(String name)
                 throws SAXException

Report the beginning of an entity. The start and end of the document entity are not reported. The start and end of the external DTD subset are reported using the pseudo-name "[dtd]". All other events must be properly nested within start/end entity events.

Specified by:

startEntity in interface LexicalHandler

Parameters:

name - The name of the entity. If it is a parameter entity, the name will begin with '%'.

Throws:

SAXException

See Also:

endEntity(java.lang.String), DeclHandler.internalEntityDecl(java.lang.String, java.lang.String), DeclHandler.externalEntityDecl(java.lang.String, java.lang.String, java.lang.String)

endEntity

public void endEntity(String name)
               throws SAXException

Report the end of an entity.

Specified by:

endEntity in interface LexicalHandler

Parameters:

name - The name of the entity that is ending.

Throws:

SAXException

See Also:

startEntity(java.lang.String)

entityReference

public void entityReference(String name)
                     throws SAXException

Receive notivication of a entityReference.

Parameters:

name - name of the entity reference

Throws:

SAXException

ignorableWhitespace

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

Receive notification of ignorable whitespace in element content.

Validating Parsers must use this method to report each chunk of ignorable whitespace (see the W3C XML 1.0 recommendation, section 2.10): non-validating parsers may also use this method if they are capable of parsing and using content models.

SAX parsers may return all contiguous whitespace in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity, so that the Locator provides useful information.

The application must not attempt to read from the array outside of the specified range.

Specified by:

ignorableWhitespace in interface ContentHandler

Parameters:

ch - The characters from the XML document.

start - The start position in the array.

length - The number of characters to read from the array.

Throws:

SAXException

See Also:

characters(char[], int, int)

processingInstruction

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

Receive notification of a processing instruction.

The Parser will invoke this method once for each processing instruction found: note that processing instructions may occur before or after the main document element.

A SAX parser should never report an XML declaration (XML 1.0, section 2.8) or a text declaration (XML 1.0, section 4.3.1) using this method.

Specified by:

processingInstruction in interface ContentHandler

Parameters:

target - The processing instruction target.

data - The processing instruction data, or null if none was supplied.

Throws:

SAXException

comment

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

Report an XML comment anywhere in the document. This callback will be used for comments inside or outside the document element, including comments in the external DTD subset (if read).

Specified by:

comment in interface LexicalHandler

Parameters:

ch - An array holding the characters in the comment.

start - The starting position in the array.

length - The number of characters to use from the array.

Throws:

SAXException

startCDATA

public void startCDATA()
                throws SAXException

Report the start of a CDATA section.

Specified by:

startCDATA in interface LexicalHandler

Throws:

SAXException

See Also:

endCDATA()

endCDATA

public void endCDATA()
              throws SAXException

Report the end of a CDATA section.

Specified by:

endCDATA in interface LexicalHandler

Throws:

SAXException

See Also:

startCDATA()

cdata

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

Receive notification of cdata.

The Parser will call this method to report each chunk of character data. SAX parsers may return all contiguous character data in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity, so that the Locator provides useful information.

The application must not attempt to read from the array outside of the specified range.

Note that some parsers will report whitespace using the ignorableWhitespace() method rather than this one (validating parsers must do so).

Parameters:

ch - The characters from the XML document.

start - The start position in the array.

length - The number of characters to read from the array.

Throws:

SAXException

See Also:

ignorableWhitespace(char[], int, int), Locator

startDTD

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

Report the start of DTD declarations, if any. Any declarations are assumed to be in the internal subset unless otherwise indicated.

Specified by:

startDTD in interface LexicalHandler

Parameters:

name - The document type name.

publicId - The declared public identifier for the external DTD subset, or null if none was declared.

systemId - The declared system identifier for the external DTD subset, or null if none was declared.

Throws:

SAXException

See Also:

endDTD(), startEntity(java.lang.String)

endDTD

public void endDTD()
            throws SAXException

Report the end of DTD declarations.

Specified by:

endDTD in interface LexicalHandler

Throws:

SAXException

See Also:

startDTD(java.lang.String, java.lang.String, java.lang.String)

startPrefixMapping

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

Begin the scope of a prefix-URI Namespace mapping.

The information from this event is not necessary for normal Namespace processing: the SAX XML reader will automatically replace prefixes for element and attribute names when the http://xml.org/sax/features/namespaces feature is true (the default).

There are cases, however, when applications need to use prefixes in character data or in attribute values, where they cannot safely be expanded automatically; the start/endPrefixMapping event supplies the information to the application to expand prefixes in those contexts itself, if necessary.

Note that start/endPrefixMapping events are not guaranteed to be properly nested relative to each-other: all startPrefixMapping events will occur before the corresponding startElement event, and all endPrefixMapping events will occur after the corresponding endElement event, but their order is not guaranteed.

Specified by:

startPrefixMapping in interface ContentHandler

Parameters:

prefix - The Namespace prefix being declared.

uri - The Namespace URI the prefix is mapped to.

Throws:

SAXException

See Also:

endPrefixMapping(java.lang.String), startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)

endPrefixMapping

public void endPrefixMapping(String prefix)
                      throws SAXException

End the scope of a prefix-URI mapping.

See startPrefixMapping for details. This event will always occur after the corresponding endElement event, but the order of endPrefixMapping events is not otherwise guaranteed.

Specified by:

endPrefixMapping in interface ContentHandler

Parameters:

prefix - The prefix that was being mapping.

Throws:

SAXException

See Also:

startPrefixMapping(java.lang.String, java.lang.String), endElement(java.lang.String, java.lang.String, java.lang.String)

skippedEntity

public void skippedEntity(String name)
                   throws SAXException

Receive notification of a skipped entity.

The Parser will invoke this method once for each entity skipped. Non-validating processors may skip entities if they have not seen the declarations (because, for example, the entity was declared in an external DTD subset). All processors may skip external entities, depending on the values of the http://xml.org/sax/features/external-general-entities and the http://xml.org/sax/features/external-parameter-entities properties.

Specified by:

skippedEntity in interface ContentHandler

Parameters:

name - The name of the skipped entity. If it is a parameter entity, the name will begin with '%'.

Throws:

SAXException