org.eclipse.persistence.internal.jaxb.DomHandlerConverter Maven / Gradle / Ivy

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/*******************************************************************************
 * Copyright (c) 1998, 2012 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
 ******************************************************************************/
package org.eclipse.persistence.internal.jaxb;

import java.lang.reflect.Method;
import javax.xml.bind.ValidationEventHandler;
import javax.xml.bind.annotation.DomHandler;
import javax.xml.transform.Source;
import javax.xml.transform.Result;
import javax.xml.transform.dom.DOMResult;

import org.xml.sax.ErrorHandler;

import org.eclipse.persistence.exceptions.JAXBException;
import org.eclipse.persistence.internal.helper.ConversionManager;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.jaxb.JAXBErrorHandler;
import org.eclipse.persistence.mappings.DatabaseMapping;
import org.eclipse.persistence.oxm.mappings.converters.XMLConverter;
import org.eclipse.persistence.oxm.XMLMarshaller;
import org.eclipse.persistence.oxm.XMLUnmarshaller;
import org.eclipse.persistence.platform.xml.XMLPlatform;
import org.eclipse.persistence.platform.xml.XMLPlatformFactory;
import org.eclipse.persistence.platform.xml.XMLTransformer;
import org.eclipse.persistence.sessions.Session;

/**
 * INTERNAL:
 * Purpose:Provide support for the JAXB DomHandler API through the use of an EclipseLink
 * Converter.
 * 
Responsibilities:

 * Wrap a provided instance of a DomHandler implementation.
 * Invoke the createUnmarshaller method on DomHandler and to a transform on unmarshal
 * Invoke the marshal method on the DomHandler on a marshal
 * 
 *
 * @author mmacivor
 *
 */
public class DomHandlerConverter implements XMLConverter {
    private DomHandler domHandler;
    private XMLPlatform xmlPlatform;
    private String domHandlerClassName;
    private Class elementClass;
    private Class resultType;

    public DomHandlerConverter(String domHandlerClassName) {
        this.domHandlerClassName = domHandlerClassName;
    }

    public void initialize(DatabaseMapping mapping, Session session) {
        try {
            ConversionManager cMgr = session.getDatasourcePlatform().getConversionManager();
            Class domHandlerClass = cMgr.convertClassNameToClass(domHandlerClassName);

            this.domHandler = domHandlerClass.newInstance();

            Method createUnmarshallerMethod = PrivilegedAccessHelper.getDeclaredMethod(domHandlerClass, "createUnmarshaller", new Class[]{ValidationEventHandler.class});
            resultType = PrivilegedAccessHelper.getMethodReturnType(createUnmarshallerMethod);

            Method getElementMethod = PrivilegedAccessHelper.getDeclaredMethod(domHandlerClass, "getElement", new Class[]{resultType});
            elementClass = PrivilegedAccessHelper.getMethodReturnType(getElementMethod);

            xmlPlatform = XMLPlatformFactory.getInstance().getXMLPlatform();
        } catch(Exception ex) {
            throw JAXBException.couldNotInitializeDomHandlerConverter(ex, domHandlerClassName, mapping.getAttributeName());
        }
    }

    public Object convertDataValueToObjectValue(Object dataValue, Session session, XMLUnmarshaller unmarshaller) {
        if(dataValue instanceof org.w3c.dom.Element) {
            ErrorHandler handler = unmarshaller.getErrorHandler();
            Result result = null;
            if(handler != null && handler instanceof JAXBErrorHandler) {
                result = domHandler.createUnmarshaller(((JAXBErrorHandler)handler).getValidationEventHandler());
            } else {
                result = domHandler.createUnmarshaller(null);
            }
            xmlPlatform.newXMLTransformer().transform((org.w3c.dom.Element)dataValue, result);
            return domHandler.getElement(result);
        }
        return dataValue;
    }

    public Object convertObjectValueToDataValue(Object objectValue, Session session, XMLMarshaller marshaller) {
        if (objectValue != null && elementClass.isAssignableFrom(objectValue.getClass())) {
            ErrorHandler handler = marshaller.getErrorHandler();
            Source source = null;
            if(handler != null && handler instanceof JAXBErrorHandler) {
                source = domHandler.marshal(objectValue, ((JAXBErrorHandler)handler).getValidationEventHandler());
            } else {
                source = domHandler.marshal(objectValue, null);
            }
            DOMResult result = new DOMResult();
            XMLTransformer xmlTransformer = xmlPlatform.newXMLTransformer();
            xmlTransformer.setFormattedOutput(marshaller.isFormattedOutput());
            xmlTransformer.transform(source, result);
            return result.getNode().getFirstChild();
        }
        return objectValue;
    }

    public boolean isMutable() {
        return true;
    }

    public Object convertDataValueToObjectValue(Object dataValue, Session session) {
        return convertDataValueToObjectValue(dataValue, session, null);
    }

    public Object convertObjectValueToDataValue(Object objectValue, Session session) {
        return convertObjectValueToDataValue(objectValue, session, null);
    }

}