PatternTokenizerFactory.java

/*
 * Licensed to ElasticSearch and Shay Banon under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. ElasticSearch 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.
 */

package org.elasticsearch.index.analysis;

import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.pattern.PatternTokenizer;
import org.elasticsearch.ElasticSearchIllegalArgumentException;
import org.elasticsearch.ElasticSearchIllegalStateException;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.inject.assistedinject.Assisted;
import org.elasticsearch.common.regex.Regex;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.settings.IndexSettings;

import java.io.IOException;
import java.io.Reader;
import java.util.regex.Pattern;

public class PatternTokenizerFactory extends AbstractTokenizerFactory {

    private final Pattern pattern;
    private final int group;

    @Inject
    public PatternTokenizerFactory(Index index, @IndexSettings Settings indexSettings, @Assisted String name, @Assisted Settings settings) {
        super(index, indexSettings, name, settings);

        String sPattern = settings.get("pattern", "\\W+" /*PatternAnalyzer.NON_WORD_PATTERN*/);
        if (sPattern == null) {
            throw new ElasticSearchIllegalArgumentException("pattern is missing for [" + name + "] tokenizer of type 'pattern'");
        }

        this.pattern = Regex.compile(sPattern, settings.get("flags"));
        this.group = settings.getAsInt("group", -1);
    }

    @Override
    public Tokenizer create(Reader reader) {
        try {
            return new PatternTokenizer(reader, pattern, group);
        } catch (IOException e) {
            throw new ElasticSearchIllegalStateException("failed to create pattern tokenizer", e);
        }
    }
}