org.hibernate.envers.boot.internal.AdditionalJaxbMappingProducerImpl.java Source code

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Here is the source code for org.hibernate.envers.boot.internal.AdditionalJaxbMappingProducerImpl.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.envers.boot.internal;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;

import org.hibernate.HibernateException;
import org.hibernate.boot.jaxb.Origin;
import org.hibernate.boot.jaxb.SourceType;
import org.hibernate.boot.jaxb.hbm.spi.JaxbHbmHibernateMapping;
import org.hibernate.boot.jaxb.internal.MappingBinder;
import org.hibernate.boot.jaxb.spi.Binding;
import org.hibernate.boot.model.source.internal.hbm.MappingDocument;
import org.hibernate.boot.spi.AdditionalJaxbMappingProducer;
import org.hibernate.boot.spi.MetadataBuildingContext;
import org.hibernate.boot.spi.MetadataImplementor;
import org.hibernate.envers.configuration.internal.MappingCollector;
import org.hibernate.service.ServiceRegistry;

import org.jboss.jandex.IndexView;
import org.jboss.logging.Logger;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;

/**
 * @author Steve Ebersole
 */
public class AdditionalJaxbMappingProducerImpl implements AdditionalJaxbMappingProducer {
    private static final Logger log = Logger.getLogger(AdditionalJaxbMappingProducerImpl.class);

    @Override
    public Collection<MappingDocument> produceAdditionalMappings(final MetadataImplementor metadata,
            IndexView jandexIndex, final MappingBinder mappingBinder,
            final MetadataBuildingContext buildingContext) {
        final ServiceRegistry serviceRegistry = metadata.getMetadataBuildingOptions().getServiceRegistry();
        final EnversService enversService = serviceRegistry.getService(EnversService.class);

        if (!enversService.isEnabled()) {
            // short-circuit if envers integration has been disabled.
            return Collections.emptyList();
        }

        final ArrayList<MappingDocument> additionalMappingDocuments = new ArrayList<MappingDocument>();

        // atm we do not have distinct origin info for envers
        final Origin origin = new Origin(SourceType.OTHER, "envers");
        //      final DOMWriter writer = new DOMWriter();

        final MappingCollector mappingCollector = new MappingCollector() {
            @Override
            public void addDocument(Document document) throws DocumentException {
                dump(document);

                // while the commented-out code here is more efficient (well, understanding that
                // this whole process is un-efficient)  it leads to un-decipherable messages when
                // we get mapping mapping errors from envers output.
                //            final DOMSource domSource = new DOMSource( writer.write( document ) );
                //            domSource.setSystemId( "envers" );
                //            final Binding jaxbBinding = mappingBinder.bind( domSource, origin );

                // this form at least allows us to get better error messages
                final ByteArrayOutputStream baos = new ByteArrayOutputStream();
                final Writer w = new PrintWriter(baos);
                try {
                    final XMLWriter xw = new XMLWriter(w, new OutputFormat(" ", true));
                    xw.write(document);
                    w.flush();
                } catch (IOException e) {
                    throw new HibernateException("Unable to bind Envers-generated XML", e);
                }

                ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
                BufferedInputStream bis = new BufferedInputStream(bais);
                final Binding jaxbBinding = mappingBinder.bind(bis, origin);

                final JaxbHbmHibernateMapping jaxbRoot = (JaxbHbmHibernateMapping) jaxbBinding.getRoot();
                additionalMappingDocuments.add(new MappingDocument(jaxbRoot, origin, buildingContext));
            }
        };

        enversService.initialize(metadata, mappingCollector);

        return additionalMappingDocuments;
    }

    private static void dump(Document document) {
        if (!log.isTraceEnabled()) {
            return;
        }

        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
        final Writer w = new PrintWriter(baos);

        try {
            final XMLWriter xw = new XMLWriter(w, new OutputFormat(" ", true));
            xw.write(document);
            w.flush();
        } catch (IOException e1) {
            e1.printStackTrace();
        }

        log.tracef("Envers-generate entity mapping -----------------------------\n%s", baos.toString());
        log.trace("------------------------------------------------------------");
    }
}