io.pelle.mango.db.util.MergingPersistenceUnitPostProcessor.java Source code

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Here is the source code for io.pelle.mango.db.util.MergingPersistenceUnitPostProcessor.java

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/**
 * Copyright (c) 2013 Christian Pelster.
 * 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Christian Pelster - initial API and implementation
 */
package io.pelle.mango.db.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.springframework.orm.jpa.persistenceunit.MutablePersistenceUnitInfo;
import org.springframework.orm.jpa.persistenceunit.PersistenceUnitPostProcessor;

/**
 * This merges all JPA entities from multiple jars. To use it, all entities must
 * be listed in their respective persistence.xml files using the <class> tag.
 * 
 * @see http://forum.springsource.org/showthread.php?t=61763
 */
public class MergingPersistenceUnitPostProcessor implements PersistenceUnitPostProcessor {
    private String targetPersistenceUnitName;

    private final Logger LOG = Logger.getLogger(MergingPersistenceUnitPostProcessor.class);

    Map<String, List<String>> puiClasses = new HashMap<String, List<String>>();

    MutablePersistenceUnitInfo targetPui;

    List<MutablePersistenceUnitInfo> puisToMerge = new ArrayList<MutablePersistenceUnitInfo>();

    private void mergeManagedClasses(MutablePersistenceUnitInfo sourcePui) {
        LOG.info(String.format("merging persistence unit '%s' to '%s'", sourcePui.getPersistenceUnitName(),
                targetPui.getPersistenceUnitName()));

        for (String managedClassName : sourcePui.getManagedClassNames()) {
            targetPui.addManagedClassName(managedClassName);
        }
    }

    /** {@inheritDoc} */
    @Override
    public void postProcessPersistenceUnitInfo(MutablePersistenceUnitInfo pui) {
        if (pui.getPersistenceUnitName().endsWith(targetPersistenceUnitName)) {
            LOG.info(String.format("target persistence unit '%s' (%s)", pui.getPersistenceUnitName(),
                    StringUtils.join(pui.getManagedClassNames().listIterator(), ",")));
            targetPui = pui;

            for (MutablePersistenceUnitInfo puiToMerge : puisToMerge) {
                mergeManagedClasses(puiToMerge);
            }
        } else {
            if (targetPui == null) {
                LOG.info(String.format("persistence unit '%s' marked for later merging (%s)",
                        pui.getPersistenceUnitName(),
                        StringUtils.join(pui.getManagedClassNames().listIterator(), ",")));
                puisToMerge.add(pui);
            } else {
                mergeManagedClasses(pui);
            }
        }
    }

    public void setTargetPersistenceUnitName(String targetPersistenceUnitName) {
        this.targetPersistenceUnitName = targetPersistenceUnitName;
    }

}