org.gridkit.coherence.search.lucene.rest.StandardRestQueryParser.java Source code

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Here is the source code for org.gridkit.coherence.search.lucene.rest.StandardRestQueryParser.java

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/**
 * Copyright 2013 Alexey Ragozin
 *
 * Licensed 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.gridkit.coherence.search.lucene.rest;

import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.queryparser.flexible.core.QueryNodeException;
import org.apache.lucene.queryparser.flexible.standard.StandardQueryParser;
import org.apache.lucene.search.Query;
import org.apache.lucene.util.Version;
import org.gridkit.coherence.search.lucene.xml.NaiveXmlSchema;

public class StandardRestQueryParser implements RestQueryParser {

    private static final Pattern VAR = Pattern.compile("[$][{]([\\w\\d]+)[}]");

    private StandardQueryParser parser;

    public StandardRestQueryParser() {
        parser = new StandardQueryParser(new StandardAnalyzer(Version.LUCENE_42));
    }

    @Override
    public Query parse(String line, Map<String, Object> parameters) {
        StringBuilder sb = new StringBuilder();
        transform(sb, line, parameters);
        String query = sb.toString();
        try {
            return parser.parse(sb.toString(), NaiveXmlSchema.WHOLE_TEXT);
        } catch (QueryNodeException e) {
            throw new IllegalArgumentException("Cannot parse query [" + query + "]", e);
        }
    }

    private void transform(StringBuilder sb, String line, Map<String, Object> parameters) {
        if (sb.length() > 4 << 10) {
            throw new IllegalArgumentException("Search query is too long");
        }
        Matcher m = VAR.matcher(line);
        if (m.find()) {
            String var = m.group(1);
            Object subq = parameters.get(var);
            if (subq == null) {
                throw new IllegalArgumentException("Query parameter '" + var + "' is missing");
            }
            sb.append(line.substring(0, m.start()));
            sb.append("(");
            transform(sb, String.valueOf(subq), parameters);
            sb.append(")");
            transform(sb, line.substring(m.end()), parameters);
        } else {
            sb.append(line);
        }
        return;
    }
}