http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
// $Id: Validator.java 888884 2009-12-09 17:36:46Z mrglavas $

package javax.xml.validation;

import java.io.IOException;

import javax.xml.transform.Result;
import javax.xml.transform.Source;

import org.w3c.dom.ls.LSResourceResolver;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;


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(Source) and validate(Source, Result) methods take a Source instance, the Source
instance must be a SAXSource, DOMSource, StAXSource or StreamSource.

Author: Kohsuke Kawaguchi
Version:$Revision: 888884 $, $Date: 2009-12-09 12:36:46 -0500 (Wed, 09 Dec 2009) $
Since:1.5
/**
 * <p>A processor that checks an XML document against {@link Schema}.</p>
 * 
 * <p>
 * A validator is a thread-unsafe and non-reentrant object.
 * In other words, it is the application's responsibility to make
 * sure that one {@link Validator} object is not used from
 * more than one thread at any given time, and while the <tt>validate</tt>
 * method is invoked, applications may not recursively call
 * the <tt>validate</tt> method.
 * <p>
 *
 * Note that while the {@link #validate(javax.xml.transform.Source)} and {@link #validate(javax.xml.transform.Source, javax.xml.transform.Result)}
 * methods take a {@link Source} instance, the <code>Source</code>
 * instance must be a <code>SAXSource</code>, <code>DOMSource</code>, <code>StAXSource</code> or <code>StreamSource</code>.
 *
 * @author  <a href="mailto:Kohsuke.Kawaguchi@Sun.com">Kohsuke Kawaguchi</a>
 * @version $Revision: 888884 $, $Date: 2009-12-09 12:36:46 -0500 (Wed, 09 Dec 2009) $
 * @since 1.5
 */
public abstract class Validator {
    
    
Constructor for derived classes.


The constructor does nothing.

 Derived classes must create Validator objects that have null ErrorHandler and null LSResourceResolver. 
/**
     * Constructor for derived classes.
     * 
     * <p>
     * The constructor does nothing.
     * 
     * <p>
     * Derived classes must create {@link Validator} objects that have
     * <tt>null</tt> {@link ErrorHandler} and
     * <tt>null</tt> {@link LSResourceResolver}.
     */
    protected Validator() {
    }
    
	
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 Validators
thus saving resources associated with the creation of new Validators.


The reset Validator is not guaranteed to have the same LSResourceResolver or ErrorHandler Objects, e.g. Object.equals(Object obj). It is guaranteed to have a functionally equal LSResourceResolver and ErrorHandler.


/**
	 * <p>Reset this <code>Validator</code> to its original configuration.</p>
	 * 
	 * <p><code>Validator</code> is reset to the same state as when it was created with
	 * {@link Schema#newValidator()}.
	 * <code>reset()</code> is designed to allow the reuse of existing <code>Validator</code>s
	 * thus saving resources associated with the creation of new <code>Validator</code>s.</p>
	 * 
	 * <p>The reset <code>Validator</code> is not guaranteed to have the same {@link LSResourceResolver} or {@link ErrorHandler}
	 * <code>Object</code>s, e.g. {@link Object#equals(Object obj)}.  It is guaranteed to have a functionally equal
	 * <code>LSResourceResolver</code> and <code>ErrorHandler</code>.</p>
	 */
	public abstract void reset();

    
Validates the specified input.


This is just a convenience method of:

validate(source,null);



See Also:
  • setErrorHandler(ErrorHandler)
/**
     * Validates the specified input.
     * 
     * <p>
     * This is just a convenience method of:
     * <pre>
     * validate(source,null);
     * </pre>
     * 
     * @see #setErrorHandler(ErrorHandler)
     */
    public void validate(Source source) throws SAXException, IOException {
        validate(source, null);
    }
    
    
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
  StAXSource
  StreamSource
 



 

  null
  OK
  OK
  OK
  OK
 

 

  SAXResult
  OK
  Err
  Err
  Err
 

 

  DOMResult
  Err
  OK
  Err
  Err
 

 

  StAXResult
  Err
  Err
  OK
  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. 
Params:
  • 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:
See Also:
/**
     * Validates the specified input and send the augmented validation
     * result to the specified output.
     * 
     * <p>
     * This method places the following restrictions on the types of
     * the {@link Source}/{@link Result} accepted.
     * 
     * <h4>{@link Source}/{@link Result} accepted:</h4>
     * <table border=1>
     * <thead>
     *  <tr>
     *   <td></td>
     *   <td>{@link javax.xml.transform.sax.SAXSource}</td>
     *   <td>{@link javax.xml.transform.dom.DOMSource}</td>
     *   <td>{@link javax.xml.transform.stax.StAXSource}</td>
     *   <td>{@link javax.xml.transform.stream.StreamSource}</td>
     *  </tr>
     * </thead>
     * <tbody>
     *  <tr>
     *   <td><tt>null</tt></td>
     *   <td>OK</td>
     *   <td>OK</td>
     *   <td>OK</td>
     *   <td>OK</td>
     *  </tr>
     *  <tr>
     *   <td>{@link javax.xml.transform.sax.SAXResult}</td>
     *   <td>OK</td>
     *   <td>Err</td>
     *   <td>Err</td>
     *   <td>Err</td>
     *  </tr>
     *  <tr>
     *   <td>{@link javax.xml.transform.dom.DOMResult}</td>
     *   <td>Err</td>
     *   <td>OK</td>
     *   <td>Err</td>
     *   <td>Err</td>
     *  </tr>
     *  <tr>
     *   <td>{@link javax.xml.transform.stax.StAXResult}</td>
     *   <td>Err</td>
     *   <td>Err</td>
     *   <td>OK</td>
     *   <td>Err</td>
     *  </tr>
     *  <tr>
     *   <td>{@link javax.xml.transform.stream.StreamResult}</td>
     *   <td>Err</td>
     *   <td>Err</td>
     *   <td>Err</td>
     *   <td>OK</td>
     *  </tr>
     * </tbody>
     * </table>
     *
     * <p>
     * To validate one {@link Source} into another kind of {@link Result}, use the identity transformer
     * (see {@link javax.xml.transform.TransformerFactory#newTransformer()}).
     * 
     * <p>
     * Errors found during the validation is sent to the specified
     * {@link ErrorHandler}.
     * 
     * <p>
     * If a document is valid, or if a document contains some errors
     * but none of them were fatal and the {@link ErrorHandler} didn't
     * throw any exception, then the method returns normally.
     * 
     * @param source
     *      XML to be validated. Must not be null.
     * 
     * @param result
     *      The {@link Result} object that receives (possibly augmented)
     *      XML. This parameter can be null if the caller is not interested
     *      in it.
     *      
     *      Note that when a {@link javax.xml.transform.dom.DOMResult} is used,
     *      a validator might just pass the same DOM node from
     *      {@link javax.xml.transform.dom.DOMSource} to
     *      {@link javax.xml.transform.dom.DOMResult}
     *      (in which case <tt>source.getNode()==result.getNode()</tt>),
     *      it might copy the entire DOM tree, or it might alter the
     *      node given by the source.
     * 
     * @throws IllegalArgumentException
     *      If the {@link Result} type doesn't match the {@link Source} type,
     *      or if the specified source is not a
     *      {@link javax.xml.transform.sax.SAXSource},
     *      {@link javax.xml.transform.dom.DOMSource},
     *      {@link javax.xml.transform.stax.StAXSource} or
     *      {@link javax.xml.transform.stream.StreamSource}. 
     * 
     * @throws SAXException
     *      If the {@link ErrorHandler} throws a {@link SAXException} or
     *      if a fatal error is found and the {@link ErrorHandler} returns
     *      normally.
     * 
     * @throws IOException
     *      If the validator is processing a
     *      {@link javax.xml.transform.sax.SAXSource} and the
     *      underlying {@link org.xml.sax.XMLReader} throws an
     *      {@link IOException}.
     * 
     * @throws NullPointerException
     *      If the <tt>source</tt> parameter is null.
     * 
     * @see #validate(Source)
     */
    public abstract void validate(Source source, Result result) throws SAXException, IOException;
    
    
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. 
Params:
  • errorHandler – 
     A new error handler to be set. This parameter can be null.
/**
     * Sets the {@link ErrorHandler} to receive errors encountered
     * during the <code>validate</code> method invocation.
     * 
     * <p>
     * Error handler can be used to customize the error handling process
     * during a validation. When an {@link ErrorHandler} is set,
     * errors found during the validation will be first sent
     * to the {@link ErrorHandler}.
     * 
     * <p>
     * The error handler can abort further validation immediately
     * by throwing {@link 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 {@link ErrorHandler} 
     * 
     * <p>
     * If any {@link Throwable} is thrown from an {@link ErrorHandler},
     * the caller of the <code>validate</code> method will be thrown
     * the same {@link Throwable} object.
     * 
     * <p>
     * {@link Validator} is not allowed to
     * throw {@link SAXException} without first reporting it to
     * {@link ErrorHandler}.
     * 
     * <p>
     * When the {@link ErrorHandler} is null, the implementation will
     * behave as if the following {@link ErrorHandler} is set:
     * <pre>
     * class DraconianErrorHandler implements {@link ErrorHandler} {
     *     public void fatalError( {@link org.xml.sax.SAXParseException} e ) throws {@link SAXException} {
     *         throw e;
     *     }
     *     public void error( {@link org.xml.sax.SAXParseException} e ) throws {@link SAXException} {
     *         throw e;
     *     }
     *     public void warning( {@link org.xml.sax.SAXParseException} e ) throws {@link SAXException} {
     *         // noop
     *     }
     * }
     * </pre>
     * 
     * <p>
     * When a new {@link Validator} object is created, initially
     * this field is set to null.
     * 
     * @param   errorHandler
     *      A new error handler to be set. This parameter can be null.
     */
    public abstract void setErrorHandler(ErrorHandler errorHandler);
    
    
Gets the current ErrorHandler set to this Validator. 
See Also:
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 this Validator has created.
/**
     * Gets the current {@link ErrorHandler} set to this {@link Validator}.
     * 
     * @return

     *      This method returns the object that was last set through
     *      the {@link #setErrorHandler(ErrorHandler)} method, or null
     *      if that method has never been called since this {@link Validator}
     *      has created.
     * 
     * @see #setErrorHandler(ErrorHandler)
     */
    public abstract ErrorHandler getErrorHandler();
    
    
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. 
Params:
  • resourceResolver – 
     A new resource resolver to be set. This parameter can be null.
/**
     * Sets the {@link LSResourceResolver} to customize
     * resource resolution while in a validation episode.
     * 
     * <p>
     * {@link Validator} uses a {@link LSResourceResolver}
     * when it needs to locate external resources while a validation,
     * although exactly what constitutes "locating external resources" is
     * up to each schema language.
     * 
     * <p>
     * When the {@link LSResourceResolver} is null, the implementation will
     * behave as if the following {@link LSResourceResolver} is set:
     * <pre>
     * class DumbLSResourceResolver implements {@link LSResourceResolver} {
     *     public {@link org.w3c.dom.ls.LSInput} resolveResource(
     *         String publicId, String systemId, String baseURI) {
     *         
     *         return null; // always return null
     *     }
     * }
     * </pre>
     * 
     * <p>
     * If a {@link LSResourceResolver} throws a {@link RuntimeException}
     *  (or instances of its derived classes),
     * then the {@link Validator} will abort the parsing and  
     * the caller of the <code>validate</code> method will receive
     * the same {@link RuntimeException}. 
     * 
     * <p>
     * When a new {@link Validator} object is created, initially
     * this field is set to null.
     * 
     * @param   resourceResolver
     *      A new resource resolver to be set. This parameter can be null.
     */
    public abstract void setResourceResolver(LSResourceResolver resourceResolver);
    
    
Gets the current LSResourceResolver set to this Validator. 
See Also:
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 this Validator has created.
/**
     * Gets the current {@link LSResourceResolver} set to this {@link Validator}.
     * 
     * @return

     *      This method returns the object that was last set through
     *      the {@link #setResourceResolver(LSResourceResolver)} method, or null
     *      if that method has never been called since this {@link Validator}
     *      has created.
     * 
     * @see #setErrorHandler(ErrorHandler)
     */
    public abstract LSResourceResolver getResourceResolver();
    
    
    
    
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.


Params:
  • name – The feature name, which is a non-null fully-qualified URI.
Throws:
See Also:
Returns:The current value of the feature (true or false).
/**
     * Look up the value of a feature flag.
     *
     * <p>The feature name is any fully-qualified URI.  It is
     * possible for a {@link 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.
     *
     * <p>Implementors are free (and encouraged) to invent their own features,
     * using names built on their own URIs.</p>
     *
     * @param name The feature name, which is a non-null fully-qualified URI.
     * @return The current value of the feature (true or false).
     * @exception org.xml.sax.SAXNotRecognizedException If the feature
     *            value can't be assigned or retrieved.
     * @exception org.xml.sax.SAXNotSupportedException When the
     *            {@link Validator} recognizes the feature name but 
     *            cannot determine its value at this time.
     * @throws NullPointerException
     *          When the name parameter is null.
     * @see #setFeature(String, boolean)
     */
    public boolean getFeature(String name) throws SAXNotRecognizedException, SAXNotSupportedException {
        if(name==null) throw new NullPointerException("the name parameter is null");
        throw new SAXNotRecognizedException(name);
    }
    
    
Set the value of a feature flag.

 Feature can be used to control the way a Validator parses schemas, although Validators 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.


Params:
  • name – The feature name, which is a non-null fully-qualified URI.
  • value – The requested value of the feature (true or false).
Throws:
See Also:
/**
     * Set the value of a feature flag.
     *
     * <p>
     * Feature can be used to control the way a {@link Validator}
     * parses schemas, although {@link Validator}s are not required
     * to recognize any specific property names.</p>
     *
     * <p>The feature name is any fully-qualified URI.  It is
     * possible for a {@link 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.</p>
     *
     * @param name The feature name, which is a non-null fully-qualified URI.
     * @param value The requested value of the feature (true or false).
     * 
     * @exception org.xml.sax.SAXNotRecognizedException If the feature
     *            value can't be assigned or retrieved.
     * @exception org.xml.sax.SAXNotSupportedException When the
     *            {@link Validator} recognizes the feature name but 
     *            cannot set the requested value.
     * @throws NullPointerException
     *          When the name parameter is null.
     * 
     * @see #getFeature(String)
     */
    public void setFeature(String name, boolean value) throws SAXNotRecognizedException, SAXNotSupportedException {
        if(name==null) throw new NullPointerException("the name parameter is null");
        throw new SAXNotRecognizedException(name);
    }
    
    
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.


Validators are not required to recognize setting any specific property names.


Params:
  • name – The property name, which is a non-null fully-qualified URI.
  • object – The requested value for the property.
Throws:
/**
     * Set the value of a property.
     *
     * <p>The property name is any fully-qualified URI.  It is
     * possible for a {@link 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.</p>
     *
     * <p>{@link Validator}s are not required to recognize setting
     * any specific property names.</p>
     *
     * @param name The property name, which is a non-null fully-qualified URI.
     * @param object The requested value for the property.
     * @exception org.xml.sax.SAXNotRecognizedException If the property
     *            value can't be assigned or retrieved.
     * @exception org.xml.sax.SAXNotSupportedException When the
     *            {@link Validator} recognizes the property name but 
     *            cannot set the requested value.
     * @throws NullPointerException
     *          When the name parameter is null.
     */
    public void setProperty(String name, Object object) throws SAXNotRecognizedException, SAXNotSupportedException {
        if(name==null) throw new NullPointerException("the name parameter is null");
        throw new SAXNotRecognizedException(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.


Validators 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.


Params:
  • name – The property name, which is a non-null fully-qualified URI.
Throws:
See Also:
Returns:The current value of the property.
/**
     * Look up the value of a property.
     *
     * <p>The property name is any fully-qualified URI.  It is
     * possible for a {@link 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.</p>
     *
     * <p>{@link Validator}s are not required to recognize any specific
     * property names.</p>
     *
     * <p>Implementors are free (and encouraged) to invent their own properties,
     * using names built on their own URIs.</p>
     *
     * @param name The property name, which is a non-null fully-qualified URI.
     * @return The current value of the property.
     * @exception org.xml.sax.SAXNotRecognizedException If the property
     *            value can't be assigned or retrieved.
     * @exception org.xml.sax.SAXNotSupportedException When the
     *            XMLReader recognizes the property name but 
     *            cannot determine its value at this time.
     * @throws NullPointerException
     *          When the name parameter is null.
     * @see #setProperty(String, Object)
     */
    public Object getProperty(String name) throws SAXNotRecognizedException, SAXNotSupportedException {
        if(name==null) throw new NullPointerException("the name parameter is null");
        throw new SAXNotRecognizedException(name);
    }
}