org.onebusaway.gtfs_transformer.deferred.DeferredValueSupport.java Source code

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Here is the source code for org.onebusaway.gtfs_transformer.deferred.DeferredValueSupport.java

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/**
 * Copyright (C) 2012 Google, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.onebusaway.gtfs_transformer.deferred;

import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.Converter;
import org.onebusaway.csv_entities.schema.BeanWrapper;
import org.onebusaway.csv_entities.schema.SingleFieldMapping;
import org.onebusaway.gtfs.model.AgencyAndId;
import org.onebusaway.gtfs.serialization.GtfsReader;
import org.onebusaway.gtfs.serialization.GtfsReaderContext;
import org.onebusaway.gtfs.serialization.mappings.ConverterFactory;

public class DeferredValueSupport {

    private final GtfsReader _reader;

    private final EntitySchemaCache _schemaCache;

    public DeferredValueSupport(GtfsReader reader, EntitySchemaCache schemaCache) {
        _reader = reader;
        _schemaCache = schemaCache;
    }

    public GtfsReader getReader() {
        return _reader;
    }

    /**
     * Returns a {@link AgencyAndId} with the specified new id value and the
     * appropriate agency id prefix. By default, we use the GTFS reader's default
     * agency id. However, if the specified bean+property has an existing
     * {@link AgencyAndId} value, we use the agency-id specified there.
     */
    public AgencyAndId resolveAgencyAndId(BeanWrapper bean, String propertyName, String newId) {
        GtfsReaderContext context = _reader.getGtfsReaderContext();
        String agencyId = context.getDefaultAgencyId();
        AgencyAndId existingId = (AgencyAndId) bean.getPropertyValue(propertyName);
        if (existingId != null) {
            agencyId = existingId.getAgencyId();
        }
        return new AgencyAndId(agencyId, newId);
    }

    /**
     * Returns a {@link Converter} that can convert values to the target value
     * type. If the target entity type + property has a custom converter defined
     * in the GTFS entity schema, we will use that as instead.
     * 
     * @param targetEntityType the target entity type whose property will be
     *          updated.
     * @param targetPropertyName the target property name for the property that
     *          will be updated on the target entity.
     * @param targetValueType the target value type we wish to convert to
     */
    public Converter resolveConverter(Class<?> targetEntityType, String targetPropertyName,
            Class<?> targetValueType) {
        SingleFieldMapping mapping = _schemaCache.getFieldMappingForCsvFieldName(targetEntityType,
                targetPropertyName);
        if (mapping == null) {
            mapping = _schemaCache.getFieldMappingForObjectFieldName(targetEntityType, targetPropertyName);
        }
        if (mapping != null) {
            if (mapping instanceof ConverterFactory) {
                ConverterFactory factory = (ConverterFactory) mapping;
                return factory.create(_reader.getContext());
            }
            if (mapping instanceof Converter) {
                return (Converter) mapping;
            }
        }
        return ConvertUtils.lookup(targetValueType);
    }
}