Class Validator
- java.lang.Object
-
- javax.xml.validation.Validator
public abstract class Validator extends Object
A processor that checks an XML document against Schema
.
A validator object is not thread-safe and not reentrant. 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.
- Since:
- 1.5
Constructor Summary
Modifier | Constructor | Description |
---|---|---|
protected | Validator() | Constructor for derived classes. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
abstract ErrorHandler | getErrorHandler() | Gets the current |
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 |
abstract void | reset() | Reset this |
abstract void | setErrorHandler(ErrorHandler errorHandler) | Sets the |
void | setFeature(String name,
boolean value) | Set the value of a feature flag. |
void | setProperty(String name,
Object object) | Set the value of a property. |
abstract void | setResourceResolver(LSResourceResolver resourceResolver) | Sets the |
void | validate(Source source) | Validates the specified input. |
abstract void | validate(Source source,
Result result) | Validates the specified input and send the augmented validation result to the specified output. |
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
Validator
protected Validator()
Constructor for derived classes.
The constructor does nothing.
Derived classes must create Validator
objects that have null
ErrorHandler
and null
LSResourceResolver
.
Method Detail
reset
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 obj)
. It is guaranteed to have a functionally equal LSResourceResolver
and ErrorHandler
.
validate
public void validate(Source source) throws SAXException, IOException
Validates the specified input.
This is just a convenience method for validate(Source source, Result result)
with result
of null
.
- Parameters:
-
source
- XML to be validated. Must be an XML document or XML element and must not be null. For backwards compatibility, the results of attempting to validate anything other than a document or element are implementation-dependent. Implementations must either recognize and process the input or throw an IllegalArgumentException. - Throws:
-
IllegalArgumentException
- If theSource
is an XML artifact that the implementation cannot validate (for example, a processing instruction). -
SAXException
- If theErrorHandler
throws aSAXException
or if a fatal error is found and theErrorHandler
returns normally. -
IOException
- If the validator is processing aSAXSource
and the underlyingXMLReader
throws anIOException
. -
NullPointerException
- Ifsource
isnull
. - See Also:
validate(Source source, Result result)
validate
public abstract void validate(Source source, Result result) throws SAXException, IOException
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.
StreamSource | SAXSource | DOMSource | StAXSource | |
---|---|---|---|---|
null | OK | OK | OK | OK |
StreamResult | OK | IllegalArgumentException | IllegalArgumentException | IllegalArgumentException |
SAXResult | IllegalArgumentException | OK | IllegalArgumentException | IllegalArgumentException |
DOMResult | IllegalArgumentException | IllegalArgumentException | OK | IllegalArgumentException |
StAXResult | IllegalArgumentException | IllegalArgumentException | IllegalArgumentException | 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 be an XML document or XML element and must not be null. For backwards compatibility, the results of attempting to validate anything other than a document or element are implementation-dependent. Implementations must either recognize and process the input or throw an IllegalArgumentException. -
result
- TheResult
object that receives (possibly augmented) XML. This parameter can be null if the caller is not interested in it. Note that when aDOMResult
is used, a validator might just pass the same DOM node fromDOMSource
toDOMResult
(in which casesource.getNode()==result.getNode()
), it might copy the entire DOM tree, or it might alter the node given by the source. - Throws:
-
IllegalArgumentException
- If theResult
type doesn't match theSource
type of if theSource
is an XML artifact that the implementation cannot validate (for example, a processing instruction). -
SAXException
- If theErrorHandler
throws aSAXException
or if a fatal error is found and theErrorHandler
returns normally. -
IOException
- If the validator is processing aSAXSource
and the underlyingXMLReader
throws anIOException
. -
NullPointerException
- If thesource
parameter isnull
. - See Also:
validate(Source source)
setErrorHandler
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 implements ErrorHandler { public void fatalError( SAXParseException e ) throws SAXException { throw e; } public void error( SAXParseException e ) throws SAXException { throw e; } public void warning( SAXParseException e ) throws SAXException { // 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.
getErrorHandler
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:
setErrorHandler(ErrorHandler)
setResourceResolver
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 implements LSResourceResolver { public LSInput 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.
getResourceResolver
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:
setErrorHandler(ErrorHandler)
getFeature
public boolean getFeature(String name) throws SAXNotRecognizedException, SAXNotSupportedException
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 theValidator
recognizes the feature name but cannot determine its value at this time. -
NullPointerException
- When the name parameter is null. - See Also:
setFeature(String, boolean)
setFeature
public void setFeature(String name, boolean value) throws SAXNotRecognizedException, SAXNotSupportedException
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 feature 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 theValidator
recognizes the feature name but cannot set the requested value. -
NullPointerException
- When the name parameter is null. - See Also:
getFeature(String)
setProperty
public void setProperty(String name, Object object) throws SAXNotRecognizedException, SAXNotSupportedException
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.
All implementations that implement JAXP 1.5 or newer are required to support the XMLConstants.ACCESS_EXTERNAL_DTD
and XMLConstants.ACCESS_EXTERNAL_SCHEMA
properties.
-
Access to external DTDs in source or Schema file is restricted to the protocols specified by the
XMLConstants.ACCESS_EXTERNAL_DTD
property. If access is denied during validation due to the restriction of this property,SAXException
will be thrown by thevalidate(Source)
method.Access to external reference set by the schemaLocation attribute is restricted to the protocols specified by the
XMLConstants.ACCESS_EXTERNAL_SCHEMA
property. If access is denied during validation due to the restriction of this property,SAXException
will be thrown by thevalidate(Source)
method.
- 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 theValidator
recognizes the property name but cannot set the requested value. -
NullPointerException
- When the name parameter is null.
getProperty
public Object getProperty(String name) throws SAXNotRecognizedException, SAXNotSupportedException
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:
setProperty(String, Object)