com.liferay.portal.kernel.search.highlight.HighlightUtil.java Source code

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Here is the source code for com.liferay.portal.kernel.search.highlight.HighlightUtil.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.kernel.search.highlight;

import com.liferay.petra.string.StringBundler;
import com.liferay.petra.string.StringPool;
import com.liferay.portal.kernel.search.Document;
import com.liferay.portal.kernel.search.Field;
import com.liferay.portal.kernel.util.ArrayUtil;
import com.liferay.portal.kernel.util.StringUtil;
import com.liferay.portal.kernel.util.Validator;

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

/**
 * @author Tibor Lipusz
 */
public class HighlightUtil {

    public static final String HIGHLIGHT_TAG_CLOSE = "</liferay-hl>";

    public static final String HIGHLIGHT_TAG_OPEN = "<liferay-hl>";

    public static final String[] HIGHLIGHTS = { "<span class=\"highlight\">", "</span>" };

    public static void addSnippet(Document document, Set<String> queryTerms, String snippet,
            String snippetFieldName) {

        if (!snippet.equals(StringPool.BLANK)) {
            Matcher matcher = _pattern.matcher(snippet);

            while (matcher.find()) {
                queryTerms.add(matcher.group(1));
            }

            snippet = StringUtil.replace(snippet, HIGHLIGHT_TAG_OPEN, StringPool.BLANK);
            snippet = StringUtil.replace(snippet, HIGHLIGHT_TAG_CLOSE, StringPool.BLANK);
        }

        document.addText(Field.SNIPPET.concat(StringPool.UNDERLINE).concat(snippetFieldName), snippet);
    }

    public static String highlight(String s, String[] queryTerms) {
        return highlight(s, queryTerms, HIGHLIGHTS[0], HIGHLIGHTS[1]);
    }

    public static String highlight(String s, String[] queryTerms, String highlight1, String highlight2) {

        if (Validator.isBlank(s) || ArrayUtil.isEmpty(queryTerms)) {
            return s;
        }

        StringBundler sb = new StringBundler(3 * queryTerms.length - 1);

        for (int i = 0; i < queryTerms.length; i++) {
            if (i != 0) {
                sb.append(StringPool.PIPE);
            }

            sb.append(Pattern.quote(queryTerms[i].trim()));

            sb.append(_REGEXP_WORD_BOUNDARY);
        }

        Pattern pattern = Pattern.compile(sb.toString(), Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE);

        return _highlight(s, pattern, highlight1, highlight2);
    }

    private static String _highlight(String s, Pattern pattern, String highlight1, String highlight2) {

        Matcher matcher = pattern.matcher(s);

        if (!matcher.find()) {
            return s;
        }

        StringBuffer sb = new StringBuffer();

        do {
            matcher.appendReplacement(sb, highlight1 + matcher.group() + highlight2);
        } while (matcher.find());

        matcher.appendTail(sb);

        return sb.toString();
    }

    private static final String _REGEXP_WORD_BOUNDARY = "\\b";

    private static final Pattern _pattern = Pattern.compile(HIGHLIGHT_TAG_OPEN + "(.*?)" + HIGHLIGHT_TAG_CLOSE);

}