public abstract class ValidatorHandler extends Object implements ContentHandler
A ValidatorHandler
object is not thread-safe and not reentrant.
In other words, it is the application's responsibility to make
sure that one ValidatorHandler
object is not used from
more than one thread at any given time.
ValidatorHandler
checks if the SAX events follow
the set of constraints described in the associated Schema
,
and additionally it may modify the SAX events (for example
by adding default values, etc.)
ValidatorHandler
extends from ContentHandler
,
but it refines the underlying ContentHandler
in
the following way:
uri
, localName
, and qname
,
even though SAX allows some of them to be null.
Similarly, the user-specified ContentHandler
will receive non-null
Strings for all three parameters.
ValidatorHandler
's
ContentHandler.startPrefixMapping(String,String)
and
ContentHandler.endPrefixMapping(String)
are invoked
properly. Similarly, the user-specified ContentHandler
will receive startPrefixMapping/endPrefixMapping events.
If the ValidatorHandler
introduces additional namespace
bindings, the user-specified ContentHandler
will receive
additional startPrefixMapping/endPrefixMapping events.
Attributes
for the
ContentHandler.startElement(String,String,String,Attributes)
method
may or may not include xmlns* attributes.
A ValidatorHandler
is automatically reset every time
the startDocument method is invoked.
This spec defines the following feature that must be recognized
by all ValidatorHandler
implementations.
http://xml.org/sax/features/namespace-prefixes
This feature controls how a ValidatorHandler
introduces
namespace bindings that were not present in the original SAX event
stream.
When this feature is set to true, it must make
sure that the user's ContentHandler
will see
the corresponding xmlns*
attribute in
the Attributes
object of the
ContentHandler.startElement(String,String,String,Attributes)
callback. Otherwise, xmlns*
attributes must not be
added to Attributes
that's passed to the
user-specified ContentHandler
.
(Note that regardless of this switch, namespace bindings are
always notified to applications through
ContentHandler.startPrefixMapping(String,String)
and
ContentHandler.endPrefixMapping(String)
methods of the
ContentHandler
specified by the user.)
Note that this feature does NOT affect the way
a ValidatorHandler
receives SAX events. It merely
changes the way it augments SAX events.
This feature is set to false
by default.
Modifier | Constructor and Description |
---|---|
protected |
ValidatorHandler()
Constructor for derived classes.
|
Modifier and Type | Method and Description |
---|---|
abstract ContentHandler |
getContentHandler()
Gets the
ContentHandler which receives the
augmented validation result. |
abstract ErrorHandler |
getErrorHandler()
Gets the current
ErrorHandler set to this ValidatorHandler . |
boolean |
getFeature(String name)
Look up the value of a feature flag.
|
Object |
getProperty(String name)
Look up the value of a property.
|
abstract LSResourceResolver |
getResourceResolver()
Gets the current
LSResourceResolver set to this ValidatorHandler . |
abstract TypeInfoProvider |
getTypeInfoProvider()
Obtains the
TypeInfoProvider implementation of this
ValidatorHandler . |
abstract void |
setContentHandler(ContentHandler receiver)
Sets the
ContentHandler which receives
the augmented validation result. |
abstract void |
setErrorHandler(ErrorHandler errorHandler)
Sets the
ErrorHandler to receive errors encountered
during the validation. |
void |
setFeature(String name,
boolean value)
Set a feature for this
ValidatorHandler . |
void |
setProperty(String name,
Object object)
Set the value of a property.
|
abstract void |
setResourceResolver(LSResourceResolver resourceResolver)
Sets the
LSResourceResolver to customize
resource resolution while in a validation episode. |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
characters, endDocument, endElement, endPrefixMapping, ignorableWhitespace, processingInstruction, setDocumentLocator, skippedEntity, startDocument, startElement, startPrefixMapping
protected ValidatorHandler()
Constructor for derived classes.
The constructor does nothing.
Derived classes must create ValidatorHandler
objects that have
null
ErrorHandler
and
null
LSResourceResolver
.
public abstract void setContentHandler(ContentHandler receiver)
ContentHandler
which receives
the augmented validation result.
When a ContentHandler
is specified, a
ValidatorHandler
will work as a filter
and basically copy the incoming events to the
specified ContentHandler
.
In doing so, a ValidatorHandler
may modify
the events, for example by adding defaulted attributes.
A ValidatorHandler
may buffer events to certain
extent, but to allow ValidatorHandler
to be used
by a parser, the following requirement has to be met.
ContentHandler.startElement(String, String, String, Attributes)
,
ContentHandler.endElement(String, String, String)
,
ContentHandler.startDocument()
, or
ContentHandler.endDocument()
are invoked on a ValidatorHandler
,
the same method on the user-specified ContentHandler
must be invoked for the same event before the callback
returns.
ValidatorHandler
may not introduce new elements that
were not present in the input.
ValidatorHandler
may not remove attributes that were
present in the input.
When a callback method on the specified ContentHandler
throws an exception, the same exception object must be thrown
from the ValidatorHandler
. The ErrorHandler
should not be notified of such an exception.
This method can be called even during a middle of a validation.
receiver
- A ContentHandler
or a null value.public abstract ContentHandler getContentHandler()
ContentHandler
which receives the
augmented validation result.getContentHandler()
method, or null
if that method has never been called since this ValidatorHandler
has created.setContentHandler(ContentHandler)
public abstract void setErrorHandler(ErrorHandler errorHandler)
ErrorHandler
to receive errors encountered
during the validation.
Error handler can be used to customize the error handling process
during a validation. When an ErrorHandler
is set,
errors found during the validation will be first sent
to the ErrorHandler
.
The error handler can abort further validation immediately
by throwing SAXException
from the handler. Or for example
it can print an error to the screen and try to continue the
validation by returning normally from the ErrorHandler
If any Throwable
is thrown from an ErrorHandler
,
the same Throwable
object will be thrown toward the
root of the call stack.
ValidatorHandler
is not allowed to
throw SAXException
without first reporting it to
ErrorHandler
.
When the ErrorHandler
is null, the implementation will
behave as if the following ErrorHandler
is set:
class DraconianErrorHandler implementsErrorHandler
{ public void fatalError(SAXParseException
e ) throwsSAXException
{ throw e; } public void error(SAXParseException
e ) throwsSAXException
{ throw e; } public void warning(SAXParseException
e ) throwsSAXException
{ // noop } }
When a new ValidatorHandler
object is created, initially
this field is set to null.
errorHandler
- A new error handler to be set. This parameter can be null.public abstract ErrorHandler getErrorHandler()
ErrorHandler
set to this ValidatorHandler
.setErrorHandler(ErrorHandler)
method, or null
if that method has never been called since this ValidatorHandler
has created.setErrorHandler(ErrorHandler)
public abstract void setResourceResolver(LSResourceResolver resourceResolver)
LSResourceResolver
to customize
resource resolution while in a validation episode.
ValidatorHandler
uses a LSResourceResolver
when it needs to locate external resources while a validation,
although exactly what constitutes "locating external resources" is
up to each schema language.
When the LSResourceResolver
is null, the implementation will
behave as if the following LSResourceResolver
is set:
class DumbLSResourceResolver implementsLSResourceResolver
{ publicLSInput
resolveResource( String publicId, String systemId, String baseURI) { return null; // always return null } }
If a LSResourceResolver
throws a RuntimeException
(or instances of its derived classes),
then the ValidatorHandler
will abort the parsing and
the caller of the validate
method will receive
the same RuntimeException
.
When a new ValidatorHandler
object is created, initially
this field is set to null.
resourceResolver
- A new resource resolver to be set. This parameter can be null.public abstract LSResourceResolver getResourceResolver()
LSResourceResolver
set to this ValidatorHandler
.setResourceResolver(LSResourceResolver)
method, or null
if that method has never been called since this ValidatorHandler
has created.setErrorHandler(ErrorHandler)
public abstract TypeInfoProvider getTypeInfoProvider()
TypeInfoProvider
implementation of this
ValidatorHandler
.
The obtained TypeInfoProvider
can be queried during a parse
to access the type information determined by the validator.
Some schema languages do not define the notion of type, for those languages, this method may not be supported. However, to be compliant with this specification, implementations for W3C XML Schema 1.0 must support this operation.
TypeInfo
.
Otherwise a non-null valid TypeInfoProvider
.public boolean getFeature(String name) throws SAXNotRecognizedException, SAXNotSupportedException
The feature name is any fully-qualified URI. It is
possible for a ValidatorHandler
to recognize a feature name but
temporarily be unable to return its value.
Some feature values may be available only in specific
contexts, such as before, during, or after a validation.
Implementors are free (and encouraged) to invent their own features, using names built on their own URIs.
name
- The feature name, which is a non-null fully-qualified URI.SAXNotRecognizedException
- If the feature
value can't be assigned or retrieved.SAXNotSupportedException
- When the
ValidatorHandler
recognizes the feature name but
cannot determine its value at this time.NullPointerException
- When name
is null
.setFeature(String, boolean)
public void setFeature(String name, boolean value) throws SAXNotRecognizedException, SAXNotSupportedException
Set a feature for this ValidatorHandler
.
Feature can be used to control the way a
ValidatorHandler
parses schemas. The feature name is
any fully-qualified URI. It is possible for a
SchemaFactory
to
expose a feature value but to be unable to change the current
value. Some feature values may be immutable or mutable only in
specific contexts, such as before, during, or after a
validation.
All implementations are required to support the XMLConstants.FEATURE_SECURE_PROCESSING
feature.
When the feature is:
true
: the implementation will limit XML processing to conform to implementation limits.
Examples include enity expansion limits and XML Schema constructs that would consume large amounts of resources.
If XML processing is limited for security reasons, it will be reported via a call to the registered
ErrorHandler.fatalError(SAXParseException exception)
.
See setErrorHandler(ErrorHandler errorHandler)
.
false
: the implementation will processing XML according to the XML specifications without
regard to possible implementation limits.
name
- The feature name, which is a non-null fully-qualified URI.value
- The requested value of the feature (true or false).SAXNotRecognizedException
- If the feature
value can't be assigned or retrieved.SAXNotSupportedException
- When the
ValidatorHandler
recognizes the feature name but
cannot set the requested value.NullPointerException
- When name
is null
.getFeature(String)
public void setProperty(String name, Object object) throws SAXNotRecognizedException, SAXNotSupportedException
The property name is any fully-qualified URI. It is
possible for a ValidatorHandler
to recognize a property name but
to be unable to change the current value.
Some property values may be immutable or mutable only
in specific contexts, such as before, during, or after
a validation.
ValidatorHandler
s are not required to recognize setting
any specific property names.
name
- The property name, which is a non-null fully-qualified URI.object
- The requested value for the property.SAXNotRecognizedException
- If the property
value can't be assigned or retrieved.SAXNotSupportedException
- When the
ValidatorHandler
recognizes the property name but
cannot set the requested value.NullPointerException
- When name
is null
.public Object getProperty(String name) throws SAXNotRecognizedException, SAXNotSupportedException
The property name is any fully-qualified URI. It is
possible for a ValidatorHandler
to recognize a property name but
temporarily be unable to return its value.
Some property values may be available only in specific
contexts, such as before, during, or after a validation.
ValidatorHandler
s are not required to recognize any specific
property names.
Implementors are free (and encouraged) to invent their own properties, using names built on their own URIs.
name
- The property name, which is a non-null fully-qualified URI.SAXNotRecognizedException
- If the property
value can't be assigned or retrieved.SAXNotSupportedException
- When the
XMLReader recognizes the property name but
cannot determine its value at this time.NullPointerException
- When name
is null
.setProperty(String, Object)
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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