nl.knaw.huygens.solr.SolrUtils.java Source code

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Here is the source code for nl.knaw.huygens.solr.SolrUtils.java

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package nl.knaw.huygens.solr;

/*
 * #%L
 * Timbuctoo VRE
 * =======
 * Copyright (C) 2012 - 2015 Huygens ING
 * =======
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */

import java.util.List;
import java.util.regex.Pattern;

import org.apache.commons.lang.StringUtils;
import org.apache.solr.parser.SolrQueryParserBase;

import com.google.common.base.Splitter;
import com.google.common.collect.Lists;

public class SolrUtils {

    // Special Lucene characters: + - & | ! ( ) { } [ ] ^ " ~ * ? : \
    private static final Pattern SPECIAL = Pattern.compile("[+\\-&|!(){}\\[\\]\\^\"~*?:\\\\]");

    public static String fuzzy(String text) {
        if (StringUtils.isBlank(text) || SPECIAL.matcher(text).find()) {
            return text;
        }
        StringBuilder builder = new StringBuilder();
        String[] terms = StringUtils.split(text);
        appendTerm(builder, terms[0]);
        for (int i = 1; i < terms.length; i++) {
            builder.append(" AND ");
            appendTerm(builder, terms[i]);
        }
        return builder.toString();
    }

    private static void appendTerm(StringBuilder builder, String term) {
        builder.append(term);
        if (term.length() < 4) {
            builder.append("~0.5");
        } else {
            builder.append("~0.7");
        }
    }

    public static String escapeFacetId(String string) {
        return SolrQueryParserBase.escape(string).replaceAll(" ", "\\\\ ");
    }

    public static List<String> splitTerms(String terms) {
        Iterable<String> split = Splitter.on(" ").split(terms);
        StringBuilder tmpTerm = null;
        boolean append = false;
        List<String> termlist = Lists.newArrayList();
        for (String part : split) {
            if (part.startsWith("\"")) {
                tmpTerm = new StringBuilder(part);
                append = true;

            } else if (part.endsWith("\"")) {
                tmpTerm.append(" ").append(part);
                termlist.add(tmpTerm.toString());
                append = false;

            } else if (append) {
                tmpTerm.append(" ").append(part);

            } else {
                termlist.add(part);
            }
        }
        return termlist;
    }

    private SolrUtils() {
        throw new AssertionError("Non-instantiable class");
    }

}