JdoPropertyUtils.java

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 *  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
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 *
 *        http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.isis.objectstore.jdo.datanucleus.metamodel;

import java.text.MessageFormat;
import java.util.List;

import javax.jdo.annotations.PrimaryKey;

import org.apache.isis.applib.filter.Filter;
import org.apache.isis.core.metamodel.spec.ObjectSpecification;
import org.apache.isis.core.metamodel.spec.feature.Contributed;
import org.apache.isis.core.metamodel.spec.feature.ObjectAssociation;
import org.apache.isis.core.metamodel.spec.feature.OneToOneAssociation;
import org.apache.isis.objectstore.jdo.metamodel.facets.object.persistencecapable.JdoPersistenceCapableFacet;
import org.apache.isis.objectstore.jdo.metamodel.util.JdoPrimaryKeyPropertyFilter;

public final class JdoPropertyUtils {

    private JdoPropertyUtils() {
    }

    /**
     * Searches for the property annotated with {@link PrimaryKey}.
     * <p>
     * Returns the {@link OneToOneAssociation} if there is precisely one; else
     * <tt>null</tt>.
     * 
     * @see JdoPrimaryKeyPropertyFilter
     */
    public static OneToOneAssociation getPrimaryKeyPropertyFor(final ObjectSpecification objectSpec) {
        return getPropertyFor(objectSpec, "@PrimaryKey", new JdoPrimaryKeyPropertyFilter());
    }

    public static boolean hasPrimaryKeyProperty(final ObjectSpecification objectSpec) {
        return getPrimaryKeyPropertyFor(objectSpec) != null;
    }
    
    private static OneToOneAssociation getPropertyFor(final ObjectSpecification objSpec, final String annotationName, final Filter<ObjectAssociation> filter) {
        if (objSpec == null || !objSpec.containsFacet(JdoPersistenceCapableFacet.class)) {
            return null;
        }
        final List<? extends ObjectAssociation> propertyList = objSpec.getAssociations(Contributed.EXCLUDED, filter);
        if (propertyList.size() == 0) {
            return JdoPropertyUtils.getPropertyFor(objSpec.superclass(), annotationName, filter);
        }
        if (propertyList.size() > 1) {
            throw new IllegalStateException(MessageFormat.format("Shouldn''t have more than one property annotated with {0} (''{1}'')", annotationName, objSpec.getFullIdentifier()));
        }
        return (OneToOneAssociation) propertyList.get(0);
    }

}