gnu.xml.pipeline
Class DomConsumer.Handler

java.lang.Object
  |
  +--gnu.xml.pipeline.DomConsumer.Handler
All Implemented Interfaces:
ContentHandler, DeclHandler, DTDHandler, LexicalHandler
Enclosing class:
DomConsumer

public static class DomConsumer.Handler
extends java.lang.Object
implements ContentHandler, LexicalHandler, DTDHandler, DeclHandler

Class used to intercept various parsing events and use them to populate a DOM document. Subclasses would typically know and use backdoors into specific DOM implementations, used to implement DTD-related functionality.

Note that if this ever throws a DOMException (runtime exception) that will indicate a bug in the DOM (e.g. doesn't support something per specification) or the parser (e.g. emitted an illegal name, or accepted illegal input data).


Field Summary
protected  DomConsumer consumer
           
 
Constructor Summary
protected DomConsumer.Handler(DomConsumer consumer)
          Subclasses may use SAX2 events to provide additional behaviors in the resulting DOM.
 
Method Summary
 void attributeDecl(java.lang.String element, java.lang.String attr, java.lang.String x, java.lang.String y, java.lang.String z)
          Report an attribute type declaration.
 void characters(char[] buf, int off, int len)
          Receive notification of character data.
 void comment(char[] buf, int off, int len)
          Report an XML comment anywhere in the document.
 void elementDecl(java.lang.String name, java.lang.String model)
          Report an element type declaration.
 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(java.lang.String uri, java.lang.String local, java.lang.String name)
          Receive notification of the end of an element.
 void endEntity(java.lang.String name)
          Report the end of an entity.
 void endPrefixMapping(java.lang.String prefix)
          End the scope of a prefix-URI mapping.
 void externalEntityDecl(java.lang.String name, java.lang.String pubid, java.lang.String sysid)
          Report a parsed external entity declaration.
protected  Document getDocument()
          Returns the document under construction.
 void ignorableWhitespace(char[] buf, int off, int len)
          Receive notification of ignorable whitespace in element content.
 void internalEntityDecl(java.lang.String name, java.lang.String value)
          Report an internal entity declaration.
 void notationDecl(java.lang.String name, java.lang.String pubid, java.lang.String sysid)
          Receive notification of a notation declaration event.
 void processingInstruction(java.lang.String target, java.lang.String data)
          Receive notification of a processing instruction.
 void setDocumentLocator(Locator l)
          Receive an object for locating the origin of SAX document events.
 void skippedEntity(java.lang.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(java.lang.String name, java.lang.String pubid, java.lang.String sysid)
          Report the start of DTD declarations, if any.
 void startElement(java.lang.String uri, java.lang.String local, java.lang.String name, Attributes attrs)
          Receive notification of the beginning of an element.
 void startEntity(java.lang.String name)
          Report the beginning of some internal and external XML entities.
 void startPrefixMapping(java.lang.String prefix, java.lang.String uri)
          Begin the scope of a prefix-URI Namespace mapping.
 void unparsedEntityDecl(java.lang.String name, java.lang.String pubid, java.lang.String sysid, java.lang.String notation)
          Receive notification of an unparsed entity declaration event.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

consumer

protected DomConsumer consumer
Constructor Detail

DomConsumer.Handler

protected DomConsumer.Handler(DomConsumer consumer)
                       throws SAXException
Subclasses may use SAX2 events to provide additional behaviors in the resulting DOM.
Method Detail

getDocument

protected Document getDocument()
Returns the document under construction.

setDocumentLocator

public void setDocumentLocator(Locator l)
Description copied from interface: ContentHandler
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
Following copied from interface: org.xml.sax.ContentHandler
Parameters:
locator - An object that can return the location of any SAX document event.
See Also:
Locator

startDocument

public void startDocument()
                   throws SAXException
Description copied from interface: ContentHandler
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
Following copied from interface: org.xml.sax.ContentHandler
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.
See Also:
ContentHandler.endDocument()

endDocument

public void endDocument()
                 throws SAXException
Description copied from interface: ContentHandler
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
Following copied from interface: org.xml.sax.ContentHandler
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.
See Also:
ContentHandler.startDocument()

processingInstruction

public void processingInstruction(java.lang.String target,
                                  java.lang.String data)
                           throws SAXParseException
Description copied from interface: ContentHandler
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 must 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
Following copied from interface: org.xml.sax.ContentHandler
Parameters:
target - The processing instruction target.
data - The processing instruction data, or null if none was supplied. The data does not include any whitespace separating it from the target.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.

characters

public void characters(char[] buf,
                       int off,
                       int len)
                throws SAXException
Description copied from interface: ContentHandler
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 in element content using the ignorableWhitespace method rather than this one (validating parsers must do so).

Specified by:
characters in interface ContentHandler
Following copied from interface: org.xml.sax.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 - Any SAX exception, possibly wrapping another exception.
See Also:
ContentHandler.ignorableWhitespace(char[], int, int), Locator

skippedEntity

public void skippedEntity(java.lang.String name)
                   throws SAXException
Description copied from interface: ContentHandler
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
Following copied from interface: org.xml.sax.ContentHandler
Parameters:
name - The name of the skipped entity. If it is a parameter entity, the name will begin with '%', and if it is the external DTD subset, it will be the string "[dtd]".
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.

startPrefixMapping

public void startPrefixMapping(java.lang.String prefix,
                               java.lang.String uri)
                        throws SAXException
Description copied from interface: ContentHandler
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 otherwise guaranteed.

There should never be start/endPrefixMapping events for the "xml" prefix, since it is predeclared and immutable.

Specified by:
startPrefixMapping in interface ContentHandler
Following copied from interface: org.xml.sax.ContentHandler
Parameters:
prefix - The Namespace prefix being declared.
uri - The Namespace URI the prefix is mapped to.
Throws:
SAXException - The client may throw an exception during processing.
See Also:
ContentHandler.endPrefixMapping(java.lang.String), ContentHandler.startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)

endPrefixMapping

public void endPrefixMapping(java.lang.String prefix)
                      throws SAXException
Description copied from interface: ContentHandler
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
Following copied from interface: org.xml.sax.ContentHandler
Parameters:
prefix - The prefix that was being mapping.
Throws:
SAXException - The client may throw an exception during processing.
See Also:
ContentHandler.startPrefixMapping(java.lang.String, java.lang.String), ContentHandler.endElement(java.lang.String, java.lang.String, java.lang.String)

startElement

public void startElement(java.lang.String uri,
                         java.lang.String local,
                         java.lang.String name,
                         Attributes attrs)
                  throws SAXParseException
Description copied from interface: ContentHandler
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.

This event allows up to three name components for each element:

  1. the Namespace URI;
  2. the local name; and
  3. the qualified (prefixed) name.

Any or all of these may be provided, depending on the values of the http://xml.org/sax/features/namespaces and the http://xml.org/sax/features/namespace-prefixes properties:

Note that the attribute list provided will contain only attributes with explicit values (specified or defaulted): #IMPLIED attributes will be omitted. The attribute list will contain attributes used for Namespace declarations (xmlns* attributes) only if the http://xml.org/sax/features/namespace-prefixes property is true (it is false by default, and support for a true value is optional).

Specified by:
startElement in interface ContentHandler
Following copied from interface: org.xml.sax.ContentHandler
Parameters:
uri - The Namespace URI, or the empty string if the element has no Namespace URI or if Namespace processing is not being performed.
localName - The local name (without prefix), or the empty string if Namespace processing is not being performed.
qName - The qualified name (with prefix), or the empty string if qualified names are not available.
atts - The attributes attached to the element. If there are no attributes, it shall be an empty Attributes object.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.
See Also:
ContentHandler.endElement(java.lang.String, java.lang.String, java.lang.String), Attributes

endElement

public void endElement(java.lang.String uri,
                       java.lang.String local,
                       java.lang.String name)
                throws SAXException
Description copied from interface: ContentHandler
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).

For information on the names, see startElement.

Specified by:
endElement in interface ContentHandler
Following copied from interface: org.xml.sax.ContentHandler
Parameters:
uri - The Namespace URI, or the empty string if the element has no Namespace URI or if Namespace processing is not being performed.
localName - The local name (without prefix), or the empty string if Namespace processing is not being performed.
qName - The qualified XML 1.0 name (with prefix), or the empty string if qualified names are not available.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.

ignorableWhitespace

public void ignorableWhitespace(char[] buf,
                                int off,
                                int len)
                         throws SAXException
Description copied from interface: ContentHandler
Receive notification of ignorable whitespace in element content.

Validating Parsers must use this method to report each chunk of whitespace in element content (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
Following copied from interface: org.xml.sax.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 - Any SAX exception, possibly wrapping another exception.
See Also:
ContentHandler.characters(char[], int, int)

startCDATA

public void startCDATA()
                throws SAXException
Description copied from interface: LexicalHandler
Report the start of a CDATA section.

The contents of the CDATA section will be reported through the regular characters event; this event is intended only to report the boundary.

Specified by:
startCDATA in interface LexicalHandler
Following copied from interface: org.xml.sax.ext.LexicalHandler
Throws:
SAXException - The application may raise an exception.
See Also:
LexicalHandler.endCDATA()

endCDATA

public void endCDATA()
              throws SAXException
Description copied from interface: LexicalHandler
Report the end of a CDATA section.
Specified by:
endCDATA in interface LexicalHandler
Following copied from interface: org.xml.sax.ext.LexicalHandler
Throws:
SAXException - The application may raise an exception.
See Also:
LexicalHandler.startCDATA()

startDTD

public void startDTD(java.lang.String name,
                     java.lang.String pubid,
                     java.lang.String sysid)
              throws SAXException
Description copied from interface: LexicalHandler
Report the start of DTD declarations, if any.

This method is intended to report the beginning of the DOCTYPE declaration; if the document has no DOCTYPE declaration, this method will not be invoked.

All declarations reported through DTDHandler or DeclHandler events must appear between the startDTD and endDTD events. Declarations are assumed to belong to the internal DTD subset unless they appear between startEntity and endEntity events. Comments and processing instructions from the DTD should also be reported between the startDTD and endDTD events, in their original order of (logical) occurrence; they are not required to appear in their correct locations relative to DTDHandler or DeclHandler events, however.

Note that the start/endDTD events will appear within the start/endDocument events from ContentHandler and before the first startElement event.

Specified by:
startDTD in interface LexicalHandler
Following copied from interface: org.xml.sax.ext.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 - The application may raise an exception.
See Also:
LexicalHandler.endDTD(), LexicalHandler.startEntity(java.lang.String)

endDTD

public void endDTD()
            throws SAXException
Description copied from interface: LexicalHandler
Report the end of DTD declarations.

This method is intended to report the end of the DOCTYPE declaration; if the document has no DOCTYPE declaration, this method will not be invoked.

Specified by:
endDTD in interface LexicalHandler
Following copied from interface: org.xml.sax.ext.LexicalHandler
Throws:
SAXException - The application may raise an exception.
See Also:
LexicalHandler.startDTD(java.lang.String, java.lang.String, java.lang.String)

comment

public void comment(char[] buf,
                    int off,
                    int len)
             throws SAXException
Description copied from interface: LexicalHandler
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). Comments in the DTD must be properly nested inside start/endDTD and start/endEntity events (if used).

Specified by:
comment in interface LexicalHandler
Following copied from interface: org.xml.sax.ext.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 - The application may raise an exception.

startEntity

public void startEntity(java.lang.String name)
                 throws SAXException
Description copied from interface: LexicalHandler
Report the beginning of some internal and external XML entities.

The reporting of parameter entities (including the external DTD subset) is optional, and SAX2 drivers that support LexicalHandler may not support it; you can use the http://xml.org/sax/features/lexical-handler/parameter-entities feature to query or control the reporting of parameter entities.

General entities are reported with their regular names, parameter entities have '%' prepended to their names, and the external DTD subset has the pseudo-entity name "[dtd]".

When a SAX2 driver is providing these events, all other events must be properly nested within start/end entity events. There is no additional requirement that events from DeclHandler or DTDHandler be properly ordered.

Note that skipped entities will be reported through the skippedEntity event, which is part of the ContentHandler interface.

Because of the streaming event model that SAX uses, some entity boundaries cannot be reported under any circumstances:

These will be silently expanded, with no indication of where the original entity boundaries were.

Note also that the boundaries of character references (which are not really entities anyway) are not reported.

All start/endEntity events must be properly nested.

Specified by:
startEntity in interface LexicalHandler
Following copied from interface: org.xml.sax.ext.LexicalHandler
Parameters:
name - The name of the entity. If it is a parameter entity, the name will begin with '%', and if it is the external DTD subset, it will be "[dtd]".
Throws:
SAXException - The application may raise an exception.
See Also:
LexicalHandler.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(java.lang.String name)
               throws SAXException
Description copied from interface: LexicalHandler
Report the end of an entity.
Specified by:
endEntity in interface LexicalHandler
Following copied from interface: org.xml.sax.ext.LexicalHandler
Parameters:
name - The name of the entity that is ending.
Throws:
SAXException - The application may raise an exception.
See Also:
LexicalHandler.startEntity(java.lang.String)

notationDecl

public void notationDecl(java.lang.String name,
                         java.lang.String pubid,
                         java.lang.String sysid)
                  throws SAXException
Description copied from interface: DTDHandler
Receive notification of a notation declaration event.

It is up to the application to record the notation for later reference, if necessary.

At least one of publicId and systemId must be non-null. If a system identifier is present, and it is a URL, the SAX parser must resolve it fully before passing it to the application through this event.

There is no guarantee that the notation declaration will be reported before any unparsed entities that use it.

Specified by:
notationDecl in interface DTDHandler
Following copied from interface: org.xml.sax.DTDHandler
Parameters:
name - The notation name.
publicId - The notation's public identifier, or null if none was given.
systemId - The notation's system identifier, or null if none was given.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.
See Also:
DTDHandler.unparsedEntityDecl(java.lang.String, java.lang.String, java.lang.String, java.lang.String), AttributeList

unparsedEntityDecl

public void unparsedEntityDecl(java.lang.String name,
                               java.lang.String pubid,
                               java.lang.String sysid,
                               java.lang.String notation)
                        throws SAXException
Description copied from interface: DTDHandler
Receive notification of an unparsed entity declaration event.

Note that the notation name corresponds to a notation reported by the notationDecl event. It is up to the application to record the entity for later reference, if necessary.

If the system identifier is a URL, the parser must resolve it fully before passing it to the application.

Specified by:
unparsedEntityDecl in interface DTDHandler
Following copied from interface: org.xml.sax.DTDHandler
Parameters:
name - The unparsed entity's name.
publicId - The entity's public identifier, or null if none was given.
systemId - The entity's system identifier.
notation - name The name of the associated notation.
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.
See Also:
DTDHandler.notationDecl(java.lang.String, java.lang.String, java.lang.String), AttributeList

elementDecl

public void elementDecl(java.lang.String name,
                        java.lang.String model)
                 throws SAXException
Description copied from interface: DeclHandler
Report an element type declaration.

The content model will consist of the string "EMPTY", the string "ANY", or a parenthesised group, optionally followed by an occurrence indicator. The model will be normalized so that all parameter entities are fully resolved and all whitespace is removed,and will include the enclosing parentheses. Other normalization (such as removing redundant parentheses or simplifying occurrence indicators) is at the discretion of the parser.

Specified by:
elementDecl in interface DeclHandler
Following copied from interface: org.xml.sax.ext.DeclHandler
Parameters:
name - The element type name.
model - The content model as a normalized string.
Throws:
SAXException - The application may raise an exception.

attributeDecl

public void attributeDecl(java.lang.String element,
                          java.lang.String attr,
                          java.lang.String x,
                          java.lang.String y,
                          java.lang.String z)
                   throws SAXException
Description copied from interface: DeclHandler
Report an attribute type declaration.

Only the effective (first) declaration for an attribute will be reported. The type will be one of the strings "CDATA", "ID", "IDREF", "IDREFS", "NMTOKEN", "NMTOKENS", "ENTITY", "ENTITIES", a parenthesized token group with the separator "|" and all whitespace removed, or the word "NOTATION" followed by a space followed by a parenthesized token group with all whitespace removed.

Any parameter entities in the attribute value will be expanded, but general entities (and character references) will not.

Specified by:
attributeDecl in interface DeclHandler
Following copied from interface: org.xml.sax.ext.DeclHandler
Parameters:
eName - The name of the associated element.
aName - The name of the attribute.
type - A string representing the attribute type.
valueDefault - A string representing the attribute default ("#IMPLIED", "#REQUIRED", or "#FIXED") or null if none of these applies.
value - A string representing the attribute's default value, or null if there is none.
Throws:
SAXException - The application may raise an exception.

internalEntityDecl

public void internalEntityDecl(java.lang.String name,
                               java.lang.String value)
                        throws SAXException
Description copied from interface: DeclHandler
Report an internal entity declaration.

Only the effective (first) declaration for each entity will be reported. All parameter entities in the value will be expanded, but general entities will not.

Specified by:
internalEntityDecl in interface DeclHandler
Following copied from interface: org.xml.sax.ext.DeclHandler
Parameters:
name - The name of the entity. If it is a parameter entity, the name will begin with '%'.
value - The replacement text of the entity.
Throws:
SAXException - The application may raise an exception.
See Also:
DeclHandler.externalEntityDecl(java.lang.String, java.lang.String, java.lang.String), DTDHandler.unparsedEntityDecl(java.lang.String, java.lang.String, java.lang.String, java.lang.String)

externalEntityDecl

public void externalEntityDecl(java.lang.String name,
                               java.lang.String pubid,
                               java.lang.String sysid)
                        throws SAXException
Description copied from interface: DeclHandler
Report a parsed external entity declaration.

Only the effective (first) declaration for each entity will be reported.

Specified by:
externalEntityDecl in interface DeclHandler
Following copied from interface: org.xml.sax.ext.DeclHandler
Parameters:
name - The name of the entity. If it is a parameter entity, the name will begin with '%'.
publicId - The declared public identifier of the entity, or null if none was declared.
systemId - The declared system identifier of the entity.
Throws:
SAXException - The application may raise an exception.
See Also:
DeclHandler.internalEntityDecl(java.lang.String, java.lang.String), DTDHandler.unparsedEntityDecl(java.lang.String, java.lang.String, java.lang.String, java.lang.String)

Source code is GPL'd in the JAXP subproject at http://savannah.gnu.org/projects/classpathx
This documentation was derived from that source code on 2001-07-12.