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java.lang.Object | +--gnu.xml.pipeline.TeeConsumer
Fans its events out to two other consumers, a "tee" filter stage in an event pipeline. Networks can be assembled with multiple output points.
Error handling should be simple if you remember that exceptions you throw will cancel later stages in that callback's pipeline, and generally the producer will stop if it sees such an exception. You may want to protect your pipeline against such backflows, making a kind of reverse filter (or valve?) so that certain exceptions thrown by your pipeline will caught and handled before the producer sees them. Just use a "try/catch" block, rememebering that really important cleanup tasks should be in "finally" clauses.
That issue isn't unique to "tee" consumers, but tee consumers have the additional twist that exceptions thrown by the first consumer will cause the second consumer not to see the callback (except for the endDocument callback, which signals state cleanup).
| Constructor Summary | |
TeeConsumer(EventConsumer car,
EventConsumer cdr)
Constructs a consumer which sends all its events to the first consumer, and then the second one. |
|
| Method Summary | |
void |
attributeDecl(java.lang.String element,
java.lang.String attribute,
java.lang.String type,
java.lang.String valueDefault,
java.lang.String value)
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 element,
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 entity,
java.lang.String publicId,
java.lang.String systemId)
Report a parsed external entity declaration. |
ContentHandler |
getContentHandler()
Returns the content handler being used. |
DTDHandler |
getDTDHandler()
Returns the dtd handler being used. |
EventConsumer |
getFirst()
Returns the first pipeline to get event calls. |
java.lang.Object |
getProperty(java.lang.String id)
Returns the declaration or lexical handler being used. |
EventConsumer |
getRest()
Returns the second pipeline to get event calls. |
void |
ignorableWhitespace(char[] buf,
int off,
int len)
Receive notification of ignorable whitespace in element content. |
void |
internalEntityDecl(java.lang.String entity,
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 |
setErrorHandler(ErrorHandler handler)
Provides the error handler to both subsequent nodes of this filter stage. |
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 atts)
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 ndata)
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 |
| Constructor Detail |
public TeeConsumer(EventConsumer car,
EventConsumer cdr)
car - The first consumer to get the eventscdr - The second consumer to get the events| Method Detail |
public EventConsumer getFirst()
public EventConsumer getRest()
public final ContentHandler getContentHandler()
getContentHandler in interface EventConsumerpublic final DTDHandler getDTDHandler()
getDTDHandler in interface EventConsumer
public final java.lang.Object getProperty(java.lang.String id)
throws SAXNotRecognizedException
getProperty in interface EventConsumergnu.xml.pipeline.EventConsumerid - This is a URI identifying the type of property desired.SAXNotRecognizedException - Thrown if the particular
pipeline stage does not understand the specified identifier.public void setErrorHandler(ErrorHandler handler)
setErrorHandler in interface EventConsumergnu.xml.pipeline.EventConsumerhandler - encapsulates error handling policy for this stagepublic void setDocumentLocator(Locator l)
ContentHandlerSAX 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.
setDocumentLocator in interface ContentHandlerorg.xml.sax.ContentHandlerlocator - An object that can return the location of
any SAX document event.Locator
public void startDocument()
throws SAXException
ContentHandlerThe SAX parser will invoke this method only once, before any
other methods in this interface or in DTDHandler (except for setDocumentLocator).
startDocument in interface ContentHandlerorg.xml.sax.ContentHandlerSAXException - Any SAX exception, possibly
wrapping another exception.ContentHandler.endDocument()
public void endDocument()
throws SAXException
ContentHandlerThe 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.
endDocument in interface ContentHandlerorg.xml.sax.ContentHandlerSAXException - Any SAX exception, possibly
wrapping another exception.ContentHandler.startDocument()
public void startPrefixMapping(java.lang.String prefix,
java.lang.String uri)
throws SAXException
ContentHandlerThe 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.
startPrefixMapping in interface ContentHandlerorg.xml.sax.ContentHandlerprefix - The Namespace prefix being declared.uri - The Namespace URI the prefix is mapped to.SAXException - The client may throw
an exception during processing.ContentHandler.endPrefixMapping(java.lang.String),
ContentHandler.startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
public void endPrefixMapping(java.lang.String prefix)
throws SAXException
ContentHandlerSee startPrefixMapping for
details. This event will always occur after the corresponding
endElement event, but the order of
endPrefixMapping events is not otherwise
guaranteed.
endPrefixMapping in interface ContentHandlerorg.xml.sax.ContentHandlerprefix - The prefix that was being mapping.SAXException - The client may throw
an exception during processing.ContentHandler.startPrefixMapping(java.lang.String, java.lang.String),
ContentHandler.endElement(java.lang.String, java.lang.String, java.lang.String)
public void skippedEntity(java.lang.String name)
throws SAXException
ContentHandlerThe 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.
skippedEntity in interface ContentHandlerorg.xml.sax.ContentHandlername - 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]".SAXException - Any SAX exception, possibly
wrapping another exception.
public void startElement(java.lang.String uri,
java.lang.String local,
java.lang.String name,
Attributes atts)
throws SAXException
ContentHandlerThe 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:
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).
startElement in interface ContentHandlerorg.xml.sax.ContentHandleruri - 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.SAXException - Any SAX exception, possibly
wrapping another exception.ContentHandler.endElement(java.lang.String, java.lang.String, java.lang.String),
Attributes
public void endElement(java.lang.String uri,
java.lang.String local,
java.lang.String name)
throws SAXException
ContentHandlerThe 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.
endElement in interface ContentHandlerorg.xml.sax.ContentHandleruri - 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.SAXException - Any SAX exception, possibly
wrapping another exception.
public void processingInstruction(java.lang.String target,
java.lang.String data)
throws SAXException
ContentHandlerThe 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.
processingInstruction in interface ContentHandlerorg.xml.sax.ContentHandlertarget - 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.SAXException - Any SAX exception, possibly
wrapping another exception.
public void characters(char[] buf,
int off,
int len)
throws SAXException
ContentHandlerThe 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).
characters in interface ContentHandlerorg.xml.sax.ContentHandlerch - The characters from the XML document.start - The start position in the array.length - The number of characters to read from the array.SAXException - Any SAX exception, possibly
wrapping another exception.ContentHandler.ignorableWhitespace(char[], int, int),
Locator
public void ignorableWhitespace(char[] buf,
int off,
int len)
throws SAXException
ContentHandlerValidating 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.
ignorableWhitespace in interface ContentHandlerorg.xml.sax.ContentHandlerch - The characters from the XML document.start - The start position in the array.length - The number of characters to read from the array.SAXException - Any SAX exception, possibly
wrapping another exception.ContentHandler.characters(char[], int, int)
public void notationDecl(java.lang.String name,
java.lang.String pubid,
java.lang.String sysid)
throws SAXException
DTDHandlerIt 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.
notationDecl in interface DTDHandlerorg.xml.sax.DTDHandlername - 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.SAXException - Any SAX exception, possibly
wrapping another exception.DTDHandler.unparsedEntityDecl(java.lang.String, java.lang.String, java.lang.String, java.lang.String),
AttributeList
public void unparsedEntityDecl(java.lang.String name,
java.lang.String pubid,
java.lang.String sysid,
java.lang.String ndata)
throws SAXException
DTDHandlerNote 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.
unparsedEntityDecl in interface DTDHandlerorg.xml.sax.DTDHandlername - 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.SAXException - Any SAX exception, possibly
wrapping another exception.DTDHandler.notationDecl(java.lang.String, java.lang.String, java.lang.String),
AttributeList
public void attributeDecl(java.lang.String element,
java.lang.String attribute,
java.lang.String type,
java.lang.String valueDefault,
java.lang.String value)
throws SAXException
DeclHandlerOnly 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.
attributeDecl in interface DeclHandlerorg.xml.sax.ext.DeclHandlereName - 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.SAXException - The application may raise an exception.
public void elementDecl(java.lang.String element,
java.lang.String model)
throws SAXException
DeclHandlerThe 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.
elementDecl in interface DeclHandlerorg.xml.sax.ext.DeclHandlername - The element type name.model - The content model as a normalized string.SAXException - The application may raise an exception.
public void externalEntityDecl(java.lang.String entity,
java.lang.String publicId,
java.lang.String systemId)
throws SAXException
DeclHandlerOnly the effective (first) declaration for each entity will be reported.
externalEntityDecl in interface DeclHandlerorg.xml.sax.ext.DeclHandlername - 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.SAXException - The application may raise an exception.DeclHandler.internalEntityDecl(java.lang.String, java.lang.String),
DTDHandler.unparsedEntityDecl(java.lang.String, java.lang.String, java.lang.String, java.lang.String)
public void internalEntityDecl(java.lang.String entity,
java.lang.String value)
throws SAXException
DeclHandlerOnly the effective (first) declaration for each entity will be reported. All parameter entities in the value will be expanded, but general entities will not.
internalEntityDecl in interface DeclHandlerorg.xml.sax.ext.DeclHandlername - The name of the entity. If it is a parameter
entity, the name will begin with '%'.value - The replacement text of the entity.SAXException - The application may raise an exception.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)
public void comment(char[] buf,
int off,
int len)
throws SAXException
LexicalHandlerThis 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).
comment in interface LexicalHandlerorg.xml.sax.ext.LexicalHandlerch - 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.SAXException - The application may raise an exception.
public void startCDATA()
throws SAXException
LexicalHandlerThe contents of the CDATA section will be reported through
the regular characters event; this event is intended only to report
the boundary.
startCDATA in interface LexicalHandlerorg.xml.sax.ext.LexicalHandlerSAXException - The application may raise an exception.LexicalHandler.endCDATA()
public void endCDATA()
throws SAXException
LexicalHandlerendCDATA in interface LexicalHandlerorg.xml.sax.ext.LexicalHandlerSAXException - The application may raise an exception.LexicalHandler.startCDATA()
public void startEntity(java.lang.String name)
throws SAXException
LexicalHandlerThe 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.
startEntity in interface LexicalHandlerorg.xml.sax.ext.LexicalHandlername - 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]".SAXException - The application may raise an exception.LexicalHandler.endEntity(java.lang.String),
DeclHandler.internalEntityDecl(java.lang.String, java.lang.String),
DeclHandler.externalEntityDecl(java.lang.String, java.lang.String, java.lang.String)
public void endEntity(java.lang.String name)
throws SAXException
LexicalHandlerendEntity in interface LexicalHandlerorg.xml.sax.ext.LexicalHandlername - The name of the entity that is ending.SAXException - The application may raise an exception.LexicalHandler.startEntity(java.lang.String)
public void startDTD(java.lang.String name,
java.lang.String pubid,
java.lang.String sysid)
throws SAXException
LexicalHandlerThis 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.
startDTD in interface LexicalHandlerorg.xml.sax.ext.LexicalHandlername - 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.SAXException - The application may raise an
exception.LexicalHandler.endDTD(),
LexicalHandler.startEntity(java.lang.String)
public void endDTD()
throws SAXException
LexicalHandlerThis method is intended to report the end of the DOCTYPE declaration; if the document has no DOCTYPE declaration, this method will not be invoked.
endDTD in interface LexicalHandlerorg.xml.sax.ext.LexicalHandlerSAXException - The application may raise an exception.LexicalHandler.startDTD(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 |
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