ca.sqlpower.dao.helper.AbstractSPPersisterHelper.java Source code

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Here is the source code for ca.sqlpower.dao.helper.AbstractSPPersisterHelper.java

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/*
 * Copyright (c) 2009, SQL Power Group Inc.
 *
 * This file is part of SQL Power Library.
 *
 * SQL Power Library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * SQL Power Library 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>. 
 */

package ca.sqlpower.dao.helper;

import java.util.List;

import ca.sqlpower.dao.PersistedSPOProperty;
import ca.sqlpower.dao.PersistedSPObject;
import ca.sqlpower.object.SPObject;

import com.google.common.collect.Multimap;

public abstract class AbstractSPPersisterHelper<T extends SPObject> implements SPPersisterHelper<T> {

    /**
     * Returns a simple string for use in exceptions from
     * {@link SPPersisterHelper#commitProperty(SPObject, String, Object)} and
     * {@link SPPersisterHelper#findProperty(SPObject, String)}. This
     * message describes that a persistable property cannot be found on the
     * object. This is refactored here as a lot of methods throw an exception
     * with a message equivalent to this one.
     * 
     * @param spo
     *            The {@link SPObject} that does not contain the given property.
     * @param propertyName
     *            The property we want to find on the {@link SPObject} that
     *            cannot be found.
     * @return An error message for exceptions that describes the above.
     */
    public static String createSPPersistenceExceptionMessage(SPObject spo, String propertyName) {
        return "Cannot persist property \"" + propertyName + "\" on " + spo.getClass() + " with name \""
                + spo.getName() + "\" and UUID \"" + spo.getUUID() + "\"";
    }

    /**
     * Finds and removes a property from a {@link Multimap} of persisted
     * properties of a given {@link SPObject}.
     * 
     * @param uuid
     *            The UUID of the {@link SPObject} to find and remove the
     *            property from.
     * @param propertyName
     *            The JavaBean property name.
     * @param persistedProperties
     *            {@link Multimap} of persisted properties to retrieve and
     *            remove the property from.
     * @return The value of the property.
     */
    public static Object findPropertyAndRemove(String uuid, String propertyName,
            Multimap<String, PersistedSPOProperty> persistedProperties) {
        for (PersistedSPOProperty property : persistedProperties.get(uuid)) {
            if (property.getPropertyName().equals(propertyName)) {
                Object newValue = property.getNewValue();
                persistedProperties.remove(uuid, property);
                return newValue;
            }
        }
        // Property might not be persisted because it might be null. 
        // We therefore need to return null.
        return null;
    }

    /**
     * Finds a property from a {@link Multimap} of persisted
     * properties of a given {@link SPObject} without removing the property.
     * 
     * @param uuid
     *            The UUID of the {@link SPObject} to find and remove the
     *            property from.
     * @param propertyName
     *            The JavaBean property name.
     * @param persistedProperties
     *            {@link Multimap} of persisted properties to retrieve and
     *            remove the property from.
     * @return The value of the property.
     */
    public static PersistedSPOProperty findProperty(String uuid, String propertyName,
            Multimap<String, PersistedSPOProperty> persistedProperties) {
        for (PersistedSPOProperty property : persistedProperties.get(uuid)) {
            if (property.getPropertyName().equals(propertyName)) {
                return property;
            }
        }
        // Property might not be persisted because it might be null. 
        // We therefore need to return null.
        return null;
    }

    /**
     * Finds the {@link PersistedSPObject} in a {@link List} that matches the
     * given UUIDs
     * 
     * @param parentUUID
     *            The {@link SPObject}'s parent UUID.
     * @param persistedObjects
     *            The {@link List} of {@link PersistedSPObject}s to search
     *            through.
     * @return The matching {@link PersistedSPObject}. If it cannot be found,
     *         null is returned.
     */
    public static PersistedSPObject findPersistedSPObject(String parentUUID, String childUUID,
            List<PersistedSPObject> persistedObjects) {
        for (PersistedSPObject pwo : persistedObjects) {
            if (pwo.isLoaded())
                continue;
            if (pwo.getParentUUID().equals(parentUUID)) {
                if (pwo.getUUID().equals(childUUID)) {
                    return pwo;
                }
            }
        }
        return null;
    }

}