com.liferay.portal.search.solr.internal.suggest.NGramQueryBuilderImpl.java Source code

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Here is the source code for com.liferay.portal.search.solr.internal.suggest.NGramQueryBuilderImpl.java

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/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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 Lesser General Public License for more
 * details.
 */

package com.liferay.portal.search.solr.internal.suggest;

import com.liferay.portal.kernel.search.Field;
import com.liferay.portal.kernel.search.SearchException;
import com.liferay.portal.kernel.search.suggest.NGramHolder;
import com.liferay.portal.kernel.search.suggest.NGramHolderBuilder;
import com.liferay.portal.kernel.util.StringBundler;
import com.liferay.portal.kernel.util.StringPool;
import com.liferay.portal.search.solr.suggest.NGramQueryBuilder;

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.solr.client.solrj.SolrQuery;

import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;
import org.osgi.service.component.annotations.ReferenceCardinality;
import org.osgi.service.component.annotations.ReferencePolicy;
import org.osgi.service.component.annotations.ReferencePolicyOption;

/**
 * @author Michael C. Han
 */
@Component(immediate = true, service = NGramQueryBuilder.class)
public class NGramQueryBuilderImpl implements NGramQueryBuilder {

    @Override
    public SolrQuery getNGramQuery(String input) throws SearchException {
        SolrQuery solrQuery = new SolrQuery();

        if (_nGramHolderBuilder == null) {
            return solrQuery;
        }

        StringBundler sb = new StringBundler(10);

        NGramHolder nGramHolder = _nGramHolderBuilder.buildNGramHolder(input);

        Map<String, List<String>> nGrams = nGramHolder.getNGrams();

        addNGramsListQuery(sb, nGrams);

        if (!nGrams.isEmpty()) {
            addOrQuerySeparator(sb);
        }

        Map<String, String> nGramEnds = nGramHolder.getNGramEnds();

        addNGramsQuery(sb, nGramEnds);

        if (!nGramEnds.isEmpty()) {
            addOrQuerySeparator(sb);
        }

        Map<String, String> nGramStarts = nGramHolder.getNGramStarts();

        addNGramsQuery(sb, nGramStarts);

        if (!nGramStarts.isEmpty()) {
            addOrQuerySeparator(sb);
        }

        sb.append(Field.SPELL_CHECK_WORD);
        sb.append(StringPool.COLON);
        sb.append(input);

        solrQuery.setQuery(sb.toString());

        return solrQuery;
    }

    protected void addNGramsListQuery(StringBundler sb, Map<String, List<String>> nGrams) {

        Set<Map.Entry<String, List<String>>> set = nGrams.entrySet();

        Iterator<Map.Entry<String, List<String>>> iterator = set.iterator();

        while (iterator.hasNext()) {
            Map.Entry<String, List<String>> entry = iterator.next();

            String fieldName = entry.getKey();
            List<String> fieldValues = entry.getValue();

            Iterator<String> fieldValuesIterator = fieldValues.iterator();

            while (fieldValuesIterator.hasNext()) {
                addQuery(sb, fieldName, fieldValuesIterator.next());

                if (fieldValuesIterator.hasNext() || iterator.hasNext()) {
                    addOrQuerySeparator(sb);
                }
            }
        }
    }

    protected void addNGramsQuery(StringBundler sb, Map<String, String> nGrams) {

        Set<Map.Entry<String, String>> set = nGrams.entrySet();

        Iterator<Map.Entry<String, String>> iterator = set.iterator();

        while (iterator.hasNext()) {
            Map.Entry<String, String> entry = iterator.next();

            String fieldName = entry.getKey();
            String fieldValue = entry.getValue();

            addQuery(sb, fieldName, fieldValue);

            if (iterator.hasNext()) {
                addOrQuerySeparator(sb);
            }
        }
    }

    protected void addOrQuerySeparator(StringBundler sb) {
        sb.append(_OR_QUERY_SEPARATOR);
    }

    protected void addQuery(StringBundler sb, String fieldName, String fieldValue) {

        sb.append(fieldName);
        sb.append(StringPool.COLON);
        sb.append(fieldValue);
    }

    @Reference(cardinality = ReferenceCardinality.OPTIONAL, policy = ReferencePolicy.DYNAMIC, policyOption = ReferencePolicyOption.GREEDY)
    protected void setNGramHolderBuilder(NGramHolderBuilder nGramHolderBuilder) {

        _nGramHolderBuilder = nGramHolderBuilder;
    }

    protected void unsetNGramHolderBuilder(NGramHolderBuilder nGramHolderBuilder) {

        _nGramHolderBuilder = null;
    }

    private static final String _OR_QUERY_SEPARATOR = " OR ";

    private NGramHolderBuilder _nGramHolderBuilder;

}