package org.apache.solr.analysis;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file 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 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.
*/
import java.io.IOException;
import java.io.InputStream;
import java.text.Collator;
import java.text.ParseException;
import java.text.RuleBasedCollator;
import java.util.Locale;
import org.apache.commons.io.IOUtils;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.collation.CollationKeyFilter;
import org.apache.solr.common.ResourceLoader;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.util.plugin.ResourceLoaderAware;
/**
* Factory for {@link CollationKeyFilter}.
* <p>
* This factory can be created in two ways:
* <ul>
* <li>Based upon a system collator associated with a Locale.
* <li>Based upon a tailored ruleset.
* </ul>
* <p>
* Using a System collator:
* <ul>
* <li>language: ISO-639 language code (mandatory)
* <li>country: ISO-3166 country code (optional)
* <li>variant: vendor or browser-specific code (optional)
* <li>strength: 'primary','secondary','tertiary', or 'identical' (optional)
* <li>decomposition: 'no','canonical', or 'full' (optional)
* </ul>
* <p>
* Using a Tailored ruleset:
* <ul>
* <li>custom: UTF-8 text file containing rules supported by RuleBasedCollator (mandatory)
* <li>strength: 'primary','secondary','tertiary', or 'identical' (optional)
* <li>decomposition: 'no','canonical', or 'full' (optional)
* </ul>
*
* @see Collator
* @see Locale
* @see RuleBasedCollator
* @since solr 1.5
*/
public class CollationKeyFilterFactory extends BaseTokenFilterFactory implements ResourceLoaderAware {
private Collator collator;
public void inform(ResourceLoader loader) {
String custom = args.get("custom");
String language = args.get("language");
String country = args.get("country");
String variant = args.get("variant");
String strength = args.get("strength");
String decomposition = args.get("decomposition");
if (custom == null && language == null)
throw new SolrException(ErrorCode.SERVER_ERROR, "Either custom or language is required.");
if (custom != null &&
(language != null || country != null || variant != null))
throw new SolrException(ErrorCode.SERVER_ERROR, "Cannot specify both language and custom. "
+ "To tailor rules for a built-in language, see the javadocs for RuleBasedCollator. "
+ "Then save the entire customized ruleset to a file, and use with the custom parameter");
if (language != null) {
// create from a system collator, based on Locale.
collator = createFromLocale(language, country, variant);
} else {
// create from a custom ruleset
collator = createFromRules(custom, loader);
}
// set the strength flag, otherwise it will be the default.
if (strength != null) {
if (strength.equalsIgnoreCase("primary"))
collator.setStrength(Collator.PRIMARY);
else if (strength.equalsIgnoreCase("secondary"))
collator.setStrength(Collator.SECONDARY);
else if (strength.equalsIgnoreCase("tertiary"))
collator.setStrength(Collator.TERTIARY);
else if (strength.equalsIgnoreCase("identical"))
collator.setStrength(Collator.IDENTICAL);
else
throw new SolrException(ErrorCode.SERVER_ERROR, "Invalid strength: " + strength);
}
// set the decomposition flag, otherwise it will be the default.
if (decomposition != null) {
if (decomposition.equalsIgnoreCase("no"))
collator.setDecomposition(Collator.NO_DECOMPOSITION);
else if (decomposition.equalsIgnoreCase("canonical"))
collator.setDecomposition(Collator.CANONICAL_DECOMPOSITION);
else if (decomposition.equalsIgnoreCase("full"))
collator.setDecomposition(Collator.FULL_DECOMPOSITION);
else
throw new SolrException(ErrorCode.SERVER_ERROR, "Invalid decomposition: " + decomposition);
}
}
public TokenStream create(TokenStream input) {
return new CollationKeyFilter(input, collator);
}
/*
* Create a locale from language, with optional country and variant.
* Then return the appropriate collator for the locale.
*/
private Collator createFromLocale(String language, String country, String variant) {
Locale locale;
if (language != null && country == null && variant != null)
throw new SolrException(ErrorCode.SERVER_ERROR,
"To specify variant, country is required");
else if (language != null && country != null && variant != null)
locale = new Locale(language, country, variant);
else if (language != null && country != null)
locale = new Locale(language, country);
else
locale = new Locale(language);
return Collator.getInstance(locale);
}
/*
* Read custom rules from a file, and create a RuleBasedCollator
* The file cannot support comments, as # might be in the rules!
*/
private Collator createFromRules(String fileName, ResourceLoader loader) {
InputStream input = null;
try {
input = loader.openResource(fileName);
String rules = IOUtils.toString(input, "UTF-8");
return new RuleBasedCollator(rules);
} catch (IOException e) {
// io error
throw new RuntimeException(e);
} catch (ParseException e) {
// invalid rules
throw new RuntimeException(e);
} finally {
IOUtils.closeQuietly(input);
}
}
}