FacetFieldFactory.java

/**
 * Copyright 2008 The University of North Carolina at Chapel Hill
 *
 * 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 edu.unc.lib.dl.search.solr.model;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.apache.solr.client.solrj.response.FacetField;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import edu.unc.lib.dl.search.solr.exception.InvalidFacetException;
import edu.unc.lib.dl.search.solr.exception.InvalidHierarchicalFacetException;
import edu.unc.lib.dl.search.solr.util.SearchSettings;
import edu.unc.lib.dl.search.solr.util.SolrSettings;

public class FacetFieldFactory {
	private static final Logger LOG = LoggerFactory.getLogger(FacetFieldFactory.class);
	
	private SearchSettings searchSettings;
	private SolrSettings solrSettings;

	public GenericFacet createFacet(String fieldKey, String facetValue) {
		Class<?> facetClass = searchSettings.getFacetClasses().get(fieldKey);
		if (facetClass == null) {
			facetClass = GenericFacet.class;
		}
		try {
			Constructor<?> constructor = facetClass.getConstructor(String.class, String.class);
			Object newFacet = constructor.newInstance(fieldKey, facetValue);
			/*if (newFacet == null)
				throw new Exception();*/
			return (GenericFacet) newFacet;
		} catch (InvocationTargetException e) {
			if (e.getCause() instanceof InvalidHierarchicalFacetException)
				throw (InvalidHierarchicalFacetException)e.getCause();
			throw new InvalidFacetException(
					"An exception occurred while attempting to instantiate a new facet field object for " + fieldKey + " "
							+ facetValue, e);
		} catch (Exception e) {
			LOG.debug(e.getClass().getName());
			throw new InvalidFacetException(
					"An exception occurred while attempting to instantiate a new facet field object for " + fieldKey + " "
							+ facetValue, e);
		}

	}

	public FacetFieldList createFacetFieldList(List<FacetField> facetFields) {
		if (facetFields == null)
			return null;
		Map<String, String> fieldNameMappings = solrSettings.getFieldNameToKey();

		FacetFieldList facetFieldList = new FacetFieldList();
		for (FacetField facetField : facetFields) {
			String fieldName = fieldNameMappings.get(facetField.getName());
			if (facetField.getValueCount() > 0) {
				facetFieldList.add(createFacetFieldObject(fieldName, facetField));
			}
		}
		return facetFieldList;
	}

	public FacetFieldObject createFacetFieldObject(String fieldKey, FacetField facetField) {
		List<GenericFacet> values = new ArrayList<GenericFacet>();

		// Generate list of facet values from Solr facet fields if they are provided.
		if (facetField != null) {
			Class<?> facetClass = searchSettings.getFacetClasses().get(fieldKey);
			if (facetClass == null) {
				facetClass = GenericFacet.class;
			}
			try {
				Constructor<?> constructor = facetClass.getConstructor(String.class, FacetField.Count.class);
				if (facetField != null) {
					for (FacetField.Count value : facetField.getValues()) {
						values.add((GenericFacet) constructor.newInstance(fieldKey, value));
					}
				}
			} catch (Exception e) {
				throw new InvalidFacetException(
						"An exception occurred while attempting to instantiate a new facet field object for " + fieldKey, e);
			}
		}

		return new FacetFieldObject(fieldKey, values);
	}

	public void addMissingFacetFieldObjects(FacetFieldList facetFieldList, Collection<String> allFacetNames) {
		for (String facetName : allFacetNames) {
			if (!facetFieldList.contains(facetName))
				facetFieldList.add(createFacetFieldObject(facetName, null));
		}
	}

	public void setSearchSettings(SearchSettings searchSettings) {
		this.searchSettings = searchSettings;
	}

	public void setSolrSettings(SolrSettings solrSettings) {
		this.solrSettings = solrSettings;
	}
}