ShingleFilter.java

/**   
 * License Agreement for OpenSearchServer
 *
 * Copyright (C) 2010 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.analysis.filter;

import org.apache.lucene.analysis.TokenStream;

import com.jaeksoft.searchlib.SearchLibException;
import com.jaeksoft.searchlib.analysis.ClassPropertyEnum;
import com.jaeksoft.searchlib.analysis.FilterFactory;
import com.jaeksoft.searchlib.analysis.shingle.ShingleTokenFilter;

public class ShingleFilter extends FilterFactory {

	private String tokenSeparator;

	private int maxShingleSize;

	private int minShingleSize;

	@Override
	protected void initProperties() throws SearchLibException {
		super.initProperties();
		addProperty(ClassPropertyEnum.TOKEN_SEPARATOR, " ", null, 10, 1);
		addProperty(ClassPropertyEnum.MAX_SHINGLE_SIZE, "2", null, 10, 1);
		addProperty(ClassPropertyEnum.MIN_SHINGLE_SIZE, "1", null, 10, 1);
	}

	@Override
	public void checkValue(ClassPropertyEnum prop, String value)
			throws SearchLibException {
		if (prop == ClassPropertyEnum.TOKEN_SEPARATOR)
			tokenSeparator = value;
		else if (prop == ClassPropertyEnum.MAX_SHINGLE_SIZE)
			maxShingleSize = Integer.parseInt(value);
		else if (prop == ClassPropertyEnum.MIN_SHINGLE_SIZE)
			minShingleSize = Integer.parseInt(value);
	}

	public void setProperties(String tokenSeparator, Integer minShingleSize,
			Integer maxShingleSize) throws SearchLibException {
		if (tokenSeparator != null)
			getProperty(ClassPropertyEnum.TOKEN_SEPARATOR).setValue(
					tokenSeparator);
		if (maxShingleSize != null)
			getProperty(ClassPropertyEnum.MAX_SHINGLE_SIZE).setValue(
					maxShingleSize.toString());
		if (minShingleSize != null)
			getProperty(ClassPropertyEnum.MIN_SHINGLE_SIZE).setValue(
					minShingleSize.toString());
	}

	@Override
	public TokenStream create(TokenStream tokenStream) {
		return new ShingleTokenFilter(tokenStream, tokenSeparator,
				minShingleSize, maxShingleSize);
	}

}