/*

 * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package javax.xml.bind.helpers;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

import org.w3c.dom.Node;

import javax.xml.bind.JAXBException;

import javax.xml.bind.PropertyException;

import javax.xml.bind.UnmarshalException;

import javax.xml.bind.Unmarshaller;

import javax.xml.bind.ValidationEventHandler;

import javax.xml.bind.JAXBElement;

import javax.xml.bind.annotation.adapters.XmlAdapter;

import javax.xml.bind.attachment.AttachmentUnmarshaller;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParserFactory;

import javax.xml.stream.XMLEventReader;

import javax.xml.stream.XMLStreamReader;

import javax.xml.transform.Source;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.sax.SAXSource;

import javax.xml.transform.stream.StreamSource;

import javax.xml.validation.Schema;

import java.io.*;

import java.net.URL;

/**

 * Partial default {@code Unmarshaller} implementation.

 *

 * <p>

 * This class provides a partial default implementation for the

 * {@link javax.xml.bind.Unmarshaller}interface.

 *

 * <p>

 * A JAXB Provider has to implement five methods (getUnmarshallerHandler,

 * unmarshal(Node), unmarshal(XMLReader,InputSource),

 * unmarshal(XMLStreamReader), and unmarshal(XMLEventReader).

 *

 * @author <ul>

 *         <li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li>

 *         </ul>

 * @see javax.xml.bind.Unmarshaller

 * @since 1.6, JAXB 1.0

 */

public abstract class AbstractUnmarshallerImpl implements Unmarshaller

{

    /** handler that will be used to process errors and warnings during unmarshal */

    private ValidationEventHandler eventHandler =

        new DefaultValidationEventHandler();

    /** whether or not the unmarshaller will validate */

    protected boolean validating = false;

    /**

     * XMLReader that will be used to parse a document.

     */

    private XMLReader reader = null;

    /**

     * Obtains a configured XMLReader.

     *

     * This method is used when the client-specified

     * {@link SAXSource} object doesn't have XMLReader.

     *

     * {@link Unmarshaller} is not re-entrant, so we will

     * only use one instance of XMLReader.

     */

    protected XMLReader getXMLReader() throws JAXBException {

        if(reader==null) {

            try {

                SAXParserFactory parserFactory;

                parserFactory = SAXParserFactory.newInstance();

                parserFactory.setNamespaceAware(true);

                // there is no point in asking a validation because

                // there is no guarantee that the document will come with

                // a proper schemaLocation.

                parserFactory.setValidating(false);

                reader = parserFactory.newSAXParser().getXMLReader();

            } catch( ParserConfigurationException e ) {

                throw new JAXBException(e);

            } catch( SAXException e ) {

                throw new JAXBException(e);

            }

        }

        return reader;

    }

    public Object unmarshal( Source source ) throws JAXBException {

        if( source == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "source" ) );

        }

        if(source instanceof SAXSource)

            return unmarshal( (SAXSource)source );

        if(source instanceof StreamSource)

            return unmarshal( streamSourceToInputSource((StreamSource)source));

        if(source instanceof DOMSource)

            return unmarshal( ((DOMSource)source).getNode() );

        // we don't handle other types of Source

        throw new IllegalArgumentException();

    }

    // use the client specified XMLReader contained in the SAXSource.

    private Object unmarshal( SAXSource source ) throws JAXBException {

        XMLReader r = source.getXMLReader();

        if( r == null )

            r = getXMLReader();

        return unmarshal( r, source.getInputSource() );

    }

    /**

     * Unmarshals an object by using the specified XMLReader and the InputSource.

     *

     * The callee should call the setErrorHandler method of the XMLReader

     * so that errors are passed to the client-specified ValidationEventHandler.

     */

    protected abstract Object unmarshal( XMLReader reader, InputSource source ) throws JAXBException;

    public final Object unmarshal( InputSource source ) throws JAXBException {

        if( source == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "source" ) );

        }

        return unmarshal( getXMLReader(), source );

    }

    private Object unmarshal( String url ) throws JAXBException {

        return unmarshal( new InputSource(url) );

    }

    public final Object unmarshal( URL url ) throws JAXBException {

        if( url == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "url" ) );

        }

        return unmarshal( url.toExternalForm() );

    }

    public final Object unmarshal( File f ) throws JAXBException {

        if( f == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "file" ) );

        }

        try {

            return unmarshal(new BufferedInputStream(new FileInputStream(f)));

        } catch( FileNotFoundException e ) {

            throw new IllegalArgumentException(e.getMessage());

        }

    }

    public final Object unmarshal( java.io.InputStream is )

        throws JAXBException {

        if( is == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "is" ) );

        }

        InputSource isrc = new InputSource( is );

        return unmarshal( isrc );

    }

    public final Object unmarshal( Reader reader ) throws JAXBException {

        if( reader == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "reader" ) );

        }

        InputSource isrc = new InputSource( reader );

        return unmarshal( isrc );

    }

    private static InputSource streamSourceToInputSource( StreamSource ss ) {

        InputSource is = new InputSource();

        is.setSystemId( ss.getSystemId() );

        is.setByteStream( ss.getInputStream() );

        is.setCharacterStream( ss.getReader() );

        return is;

    }

    /**

     * Indicates whether or not the Unmarshaller is configured to validate

     * during unmarshal operations.

     * <p>

     * <i><b>Note:</b> I named this method isValidating() to stay in-line

     * with JAXP, as opposed to naming it getValidating(). </i>

     *

     * @return true if the Unmarshaller is configured to validate during

     *        unmarshal operations, false otherwise

     * @throws JAXBException if an error occurs while retrieving the validating

     *        flag

     */

    public boolean isValidating() throws JAXBException {

        return validating;

    }

    /**

     * Allow an application to register a validation event handler.

     * <p>

     * The validation event handler will be called by the JAXB Provider if any

     * validation errors are encountered during calls to any of the

     * {@code unmarshal} methods.  If the client application does not register

     * a validation event handler before invoking the unmarshal methods, then

     * all validation events will be silently ignored and may result in

     * unexpected behaviour.

     *

     * @param handler the validation event handler

     * @throws JAXBException if an error was encountered while setting the

     *        event handler

     */

    public void setEventHandler(ValidationEventHandler handler)

        throws JAXBException {

        if( handler == null ) {

            eventHandler = new DefaultValidationEventHandler();

        } else {

            eventHandler = handler;

        }

    }

    /**

     * Specifies whether or not the Unmarshaller should validate during

     * unmarshal operations. By default, the {@code Unmarshaller} does

     * not validate.

     * <p>

     * This method may only be invoked before or after calling one of the

     * unmarshal methods.

     *

     * @param validating true if the Unmarshaller should validate during

     *       unmarshal, false otherwise

     * @throws JAXBException if an error occurred while enabling or disabling

     * validation at unmarshal time

     */

    public void setValidating(boolean validating) throws JAXBException {

        this.validating = validating;

    }

    /**

     * Return the current event handler or the default event handler if one

     * hasn't been set.

     *

     * @return the current ValidationEventHandler or the default event handler

     *        if it hasn't been set

     * @throws JAXBException if an error was encountered while getting the

     *        current event handler

     */

    public ValidationEventHandler getEventHandler() throws JAXBException {

        return eventHandler;

    }

    /**

     * Creates an UnmarshalException from a SAXException.

     *

     * This is an utility method provided for the derived classes.

     *

     * <p>

     * When a provider-implemented ContentHandler wants to throw a

     * JAXBException, it needs to wrap the exception by a SAXException.

     * If the unmarshaller implementation blindly wrap SAXException

     * by JAXBException, such an exception will be a JAXBException

     * wrapped by a SAXException wrapped by another JAXBException.

     * This is silly.

     *

     * <p>

     * This method checks the nested exception of SAXException

     * and reduce those excessive wrapping.

     *

     * @return the resulting UnmarshalException

     */

    protected UnmarshalException createUnmarshalException( SAXException e ) {

        // check the nested exception to see if it's an UnmarshalException

        Exception nested = e.getException();

        if(nested instanceof UnmarshalException)

            return (UnmarshalException)nested;

        if(nested instanceof RuntimeException)

            // typically this is an unexpected exception,

            // just throw it rather than wrap it, so that the full stack

            // trace can be displayed.

            throw (RuntimeException)nested;

        // otherwise simply wrap it

        if(nested!=null)

            return new UnmarshalException(nested);

        else

            return new UnmarshalException(e);

    }

    /**

     * Default implementation of the setProperty method always

     * throws PropertyException since there are no required

     * properties. If a provider needs to handle additional

     * properties, it should override this method in a derived class.

     */

    public void setProperty( String name, Object value )

        throws PropertyException {

        if( name == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "name" ) );

        }

        throw new PropertyException(name, value);

    }

    /**

     * Default implementation of the getProperty method always

     * throws PropertyException since there are no required

     * properties. If a provider needs to handle additional

     * properties, it should override this method in a derived class.

     */

    public Object getProperty( String name )

        throws PropertyException {

        if( name == null ) {

            throw new IllegalArgumentException(

                Messages.format( Messages.MUST_NOT_BE_NULL, "name" ) );

        }

        throw new PropertyException(name);

    }

    public Object unmarshal(XMLEventReader reader) throws JAXBException {

        throw new UnsupportedOperationException();

    }

    public Object unmarshal(XMLStreamReader reader) throws JAXBException {

        throw new UnsupportedOperationException();

    }

    public <T> JAXBElement<T> unmarshal(Node node, Class<T> expectedType) throws JAXBException {

        throw new UnsupportedOperationException();

    }

    public <T> JAXBElement<T> unmarshal(Source source, Class<T> expectedType) throws JAXBException {

        throw new UnsupportedOperationException();

    }

    public <T> JAXBElement<T> unmarshal(XMLStreamReader reader, Class<T> expectedType) throws JAXBException {

        throw new UnsupportedOperationException();

    }

    public <T> JAXBElement<T> unmarshal(XMLEventReader reader, Class<T> expectedType) throws JAXBException {

        throw new UnsupportedOperationException();

    }

    public void setSchema(Schema schema) {

        throw new UnsupportedOperationException();

    }

    public Schema getSchema() {

        throw new UnsupportedOperationException();

    }

    public void setAdapter(XmlAdapter adapter) {

        if(adapter==null)

            throw new IllegalArgumentException();

        setAdapter((Class)adapter.getClass(),adapter);

    }

    public <A extends XmlAdapter> void setAdapter(Class<A> type, A adapter) {

        throw new UnsupportedOperationException();

    }

    public <A extends XmlAdapter> A getAdapter(Class<A> type) {

        throw new UnsupportedOperationException();

    }

    public void setAttachmentUnmarshaller(AttachmentUnmarshaller au) {

        throw new UnsupportedOperationException();

    }

    public AttachmentUnmarshaller getAttachmentUnmarshaller() {

        throw new UnsupportedOperationException();

    }

    public void setListener(Listener listener) {

        throw new UnsupportedOperationException();

    }

    public Listener getListener() {

        throw new UnsupportedOperationException();

    }

}