// original code from Apache Solr - ported to work with Lucene 3.x and reformatted to Search coding style
package org.apache.solr.analysis;
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 );
}
}
}