org.apache.mahout.utils.regex.AnalyzerTransformer.java Source code

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Here is the source code for org.apache.mahout.utils.regex.AnalyzerTransformer.java

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/*
 * 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.
 */

package org.apache.mahout.utils.regex;

import com.google.common.io.Closeables;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.util.Version;
import org.apache.mahout.common.lucene.TokenStreamIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.StringReader;

public class AnalyzerTransformer implements RegexTransformer {

    private Analyzer analyzer;
    private String fieldName = "text";

    private static final Logger log = LoggerFactory.getLogger(AnalyzerTransformer.class);

    public AnalyzerTransformer() {
        this(new StandardAnalyzer(Version.LUCENE_46), "text");
    }

    public AnalyzerTransformer(Analyzer analyzer) {
        this(analyzer, "text");
    }

    public AnalyzerTransformer(Analyzer analyzer, String fieldName) {
        this.analyzer = analyzer;
        this.fieldName = fieldName;
    }

    @Override
    public String transformMatch(String match) {
        StringBuilder result = new StringBuilder();
        TokenStream ts = null;
        try {
            ts = analyzer.tokenStream(fieldName, new StringReader(match));
            ts.addAttribute(CharTermAttribute.class);
            ts.reset();
            TokenStreamIterator iter = new TokenStreamIterator(ts);
            while (iter.hasNext()) {
                result.append(iter.next()).append(' ');
            }
            ts.end();
        } catch (IOException e) {
            throw new IllegalStateException(e);
        } finally {
            try {
                Closeables.close(ts, true);
            } catch (IOException e) {
                log.error(e.getMessage(), e);
            }
        }
        return result.toString();
    }

    public Analyzer getAnalyzer() {
        return analyzer;
    }

    public void setAnalyzer(Analyzer analyzer) {
        this.analyzer = analyzer;
    }
}