com.jaeksoft.searchlib.function.expression.RootExpression.java Source code

Introduction

Here is the source code for com.jaeksoft.searchlib.function.expression.RootExpression.java

Source

/**   
 * License Agreement for OpenSearchServer
 *
 * Copyright (C) 2008-2012 Emmanuel Keller / Jaeksoft
 * 
 * http://www.open-search-server.com
 * 
 * This file is part of OpenSearchServer.
 *
 * OpenSearchServer 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.
 *
 * OpenSearchServer 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 OpenSearchServer. 
 *  If not, see <http://www.gnu.org/licenses/>.
 **/

package com.jaeksoft.searchlib.function.expression;

import java.util.ArrayList;

import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.function.ValueSourceQuery;

import com.jaeksoft.searchlib.util.StringUtils;

public class RootExpression extends GroupExpression {

    protected ArrayList<FunctionValueSource> functionValueSources;

    protected RootExpression(char[] chars, int pos) throws SyntaxError {
        super(null, chars, pos);
    }

    public FunctionValueSource functionValueSource(String func, String field) throws SyntaxError {
        if (functionValueSources == null)
            functionValueSources = new ArrayList<FunctionValueSource>();
        FunctionValueSource fvs = new FunctionValueSource(func, field, functionValueSources.size());
        for (FunctionValueSource functionValueSource : functionValueSources)
            if (functionValueSource.equals(fvs))
                return functionValueSource;
        functionValueSources.add(fvs);
        return fvs;
    }

    private ValueSourceQuery getValueSourceQuery() {
        return new ValueSourceQuery(functionValueSources.get(0).valueSource);
    }

    private ValueSourceQuery[] getValueSourceQueries() {
        ValueSourceQuery[] vsq = new ValueSourceQuery[functionValueSources.size()];
        int i = 0;
        for (FunctionValueSource fvs : functionValueSources)
            vsq[i++] = new ValueSourceQuery(fvs.valueSource);
        return vsq;
    }

    protected ScoreFunctionQuery getQuery(Query subQuery) throws SyntaxError {
        if (functionValueSources == null)
            return new ScoreFunctionQuery(subQuery, this);
        switch (functionValueSources.size()) {
        case 0:
            return new ScoreFunctionQuery(subQuery, this);
        case 1:
            return new ScoreFunctionQuery(subQuery, getValueSourceQuery(), this);
        default:
            return new ScoreFunctionQuery(subQuery, getValueSourceQueries(), this);
        }

    }

    static public ScoreFunctionQuery getQuery(Query subQuery, String exp) throws SyntaxError {
        exp = StringUtils.replaceConsecutiveSpaces(exp.trim(), "");
        return new RootExpression(exp.toCharArray(), 0).getQuery(subQuery);
    }

    public static void main(String[] argv) {
        String exp = " 10000 / ( 1 * rord(creationDate) + 10000 ) ";
        try {
            System.out.println(getQuery(new BooleanQuery(), exp));
        } catch (SyntaxError e) {
            System.err.println(e.getMessage());
        }
    }

}