org.codice.solr.xpath.XpathQueryParser.java Source code

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Here is the source code for org.codice.solr.xpath.XpathQueryParser.java

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/**
 * Copyright (c) Codice Foundation
 * <p>
 * This 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 3 of the
 * License, or any later version.
 * <p>
 * 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
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package org.codice.solr.xpath;

import org.apache.commons.lang.StringUtils;
import org.apache.lucene.search.Query;
import org.apache.solr.search.SolrQueryParser;
import org.apache.solr.search.SyntaxError;

/**
 * XPath query parser that will create Lucene and Post Filter queries to support XPath.
 */
public class XpathQueryParser extends SolrQueryParser {

    private final XpathQParser parser;

    public XpathQueryParser(XpathQParser parser, String defaultField) {
        super(parser, defaultField);
        this.parser = parser;
    }

    @Override
    protected Query getFieldQuery(String field, String queryText, boolean quoted) throws SyntaxError {

        if (field.equals("xpath")) {
            // post-filter with Saxon
            return new XpathFilterQuery(queryText);
        } else if (field.equals("xpath_index")) {
            // pre-filter with xpath index
            return getLuceneQuery(queryText);
        } else {
            // pass-through any non-XPath related fields
            return super.getFieldQuery(field, queryText, quoted);
        }
    }

    /**
     * Converts XPath into a Lucene query that will pre-filter based on xpath path and attribute
     * index fields. Further post filtering is needed for XPath functionality that cannot evaluated
     * against xpath index.
     *
     * @param queryText
     *            XPath expression to convert into lucene path and attribute index query
     * @return Lucene query to pre-filter using xpath index
     */
    private Query getLuceneQuery(final String queryText) {
        String xpath = queryText;

        // Assume root is context node since evaluation does not have a context item
        if (StringUtils.startsWith(xpath, "./")) {
            xpath = StringUtils.removeStart(xpath, ".");
        } else if (!StringUtils.startsWith(xpath, "/")) {
            xpath = "/" + xpath;
        }

        return null; // TODO DDF-1882 add lucene xpath pre-filtering
    }

}