A processor that checks an XML document against Schema
.
A validator is a thread-unsafe and non-reentrant object.
In other words, it is the application's responsibility to make
sure that one Validator
object is not used from
more than one thread at any given time, and while the validate
method is invoked, applications may not recursively call
the validate method.
Note that while the validate(javax.xml.transform.Source)
and validate(javax.xml.transform.Source, javax.xml.transform.Result)
methods take a Source
instance, the Source
instance must be a SAXSource
, DOMSource
, StAXSource
or StreamSource
.
Protected Constructor Summary
Validator()
Constructor for derived classes.
|
Public Method Summary
abstract ErrorHandler |
getErrorHandler()
Gets the current
ErrorHandler set to this Validator . |
boolean | |
Object | |
abstract LSResourceResolver |
getResourceResolver()
Gets the current
LSResourceResolver set to this Validator . |
abstract void |
reset()
Reset this |
abstract void |
setErrorHandler(ErrorHandler errorHandler)
Sets the
ErrorHandler to receive errors encountered
during the validate method invocation. |
void | |
void | |
abstract void |
setResourceResolver(LSResourceResolver resourceResolver)
Sets the
LSResourceResolver to customize
resource resolution while in a validation episode. |
void | |
abstract void |
Inherited Method Summary
Protected Constructors
protected Validator ()
Constructor for derived classes.
The constructor does nothing.
Derived classes must create Validator
objects that have
null ErrorHandler
and
null LSResourceResolver
.
Public Methods
public abstract ErrorHandler getErrorHandler ()
Gets the current ErrorHandler
set to this Validator
.
Returns
- This method returns the object that was last set through
the
setErrorHandler(ErrorHandler)
method, or null if that method has never been called since thisValidator
has created.
See Also
public boolean getFeature (String name)
Look up the value of a feature flag.
The feature name is any fully-qualified URI. It is
possible for a Validator
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.
Parameters
name | The feature name, which is a non-null fully-qualified URI. |
---|
Returns
- The current value of the feature (true or false).
Throws
SAXNotRecognizedException | If the feature value can't be assigned or retrieved. |
---|---|
SAXNotSupportedException | When the
Validator recognizes the feature name but
cannot determine its value at this time. |
NullPointerException | When the name parameter is null. |
See Also
public Object getProperty (String name)
Look up the value of a property.
The property name is any fully-qualified URI. It is
possible for a Validator
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.
Validator
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.
Parameters
name | The property name, which is a non-null fully-qualified URI. |
---|
Returns
- The current value of the property.
Throws
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 the name parameter is null. |
See Also
public abstract LSResourceResolver getResourceResolver ()
Gets the current LSResourceResolver
set to this Validator
.
Returns
- This method returns the object that was last set through
the
setResourceResolver(LSResourceResolver)
method, or null if that method has never been called since thisValidator
has created.
See Also
public abstract void reset ()
Reset this Validator
to its original configuration.
Validator
is reset to the same state as when it was created with
Schema.newValidator()
.
reset()
is designed to allow the reuse of existing Validator
s
thus saving resources associated with the creation of new Validator
s.
The reset Validator
is not guaranteed to have the same LSResourceResolver
or ErrorHandler
Object
s, e.g. Object.equals(Object)
. It is guaranteed to have a functionally equal
LSResourceResolver
and ErrorHandler
.
public abstract void setErrorHandler (ErrorHandler errorHandler)
Sets the ErrorHandler
to receive errors encountered
during the validate
method invocation.
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 caller of the validate
method will be thrown
the same Throwable
object.
Validator
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 Validator
object is created, initially
this field is set to null.
Parameters
errorHandler | A new error handler to be set. This parameter can be null. |
---|
public void setFeature (String name, boolean value)
Set the value of a feature flag.
Feature can be used to control the way a Validator
parses schemas, although Validator
s are not required
to recognize any specific property names.
The feature name is any fully-qualified URI. It is
possible for a Validator
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.
Parameters
name | The feature name, which is a non-null fully-qualified URI. |
---|---|
value | The requested value of the feature (true or false). |
Throws
SAXNotRecognizedException | If the feature value can't be assigned or retrieved. |
---|---|
SAXNotSupportedException | When the
Validator recognizes the feature name but
cannot set the requested value. |
NullPointerException | When the name parameter is null. |
See Also
public void setProperty (String name, Object object)
Set the value of a property.
The property name is any fully-qualified URI. It is
possible for a Validator
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.
Validator
s are not required to recognize setting
any specific property names.
Parameters
name | The property name, which is a non-null fully-qualified URI. |
---|---|
object | The requested value for the property. |
Throws
SAXNotRecognizedException | If the property value can't be assigned or retrieved. |
---|---|
SAXNotSupportedException | When the
Validator recognizes the property name but
cannot set the requested value. |
NullPointerException | When the name parameter is null. |
public abstract void setResourceResolver (LSResourceResolver resourceResolver)
Sets the LSResourceResolver
to customize
resource resolution while in a validation episode.
Validator
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 Validator
will abort the parsing and
the caller of the validate
method will receive
the same RuntimeException
.
When a new Validator
object is created, initially
this field is set to null.
Parameters
resourceResolver | A new resource resolver to be set. This parameter can be null. |
---|
public void validate (Source source)
Validates the specified input.
This is just a convenience method of:
validate(source,null);
Parameters
source |
---|
Throws
SAXException | |
---|---|
IOException |
See Also
public abstract void validate (Source source, Result result)
Validates the specified input and send the augmented validation result to the specified output.
This method places the following restrictions on the types of
the Source
/Result
accepted.
Source
/Result
accepted:
SAXSource |
DOMSource |
StreamSource |
||
null | OK | OK | OK | OK |
SAXResult |
OK | Err | Err | Err |
DOMResult |
Err | OK | Err | Err |
StreamResult |
Err | Err | Err | OK |
To validate one Source
into another kind of Result
, use the identity transformer
(see TransformerFactory.newTransformer()
).
Errors found during the validation is sent to the specified
ErrorHandler
.
If a document is valid, or if a document contains some errors
but none of them were fatal and the ErrorHandler
didn't
throw any exception, then the method returns normally.
Parameters
source | XML to be validated. Must not be null. |
---|---|
result | The Result object that receives (possibly augmented)
XML. This parameter can be null if the caller is not interested
in it.
Note that when a DOMResult is used,
a validator might just pass the same DOM node from
DOMSource to
DOMResult
(in which case source.getNode()==result.getNode()),
it might copy the entire DOM tree, or it might alter the
node given by the source. |
Throws
IllegalArgumentException | If the Result type doesn't match the Source type,
or if the specified source is not a
SAXSource ,
DOMSource or
StreamSource . |
---|---|
SAXException | If the ErrorHandler throws a SAXException or
if a fatal error is found and the ErrorHandler returns
normally. |
IOException | If the validator is processing a
SAXSource and the
underlying XMLReader throws an
IOException . |
NullPointerException | If the source parameter is null. |