org.apache.nutch.parse.html
Class DOMBuilder

java.lang.Object
  extended by 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


Copyright © 2006 The Apache Software Foundation