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Lucene example source code file (SpanGradientFormatter.java)

This example Lucene source code file (SpanGradientFormatter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Lucene tags/keywords

eeeeee, extra, extra, gradientformatter, override, spangradientformatter, spangradientformatter, string, string, stringbuilder, stringbuilder, template, tokengroup

The Lucene SpanGradientFormatter.java source code

package org.apache.lucene.search.highlight;
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.

 * Formats text with different color intensity depending on the score of the
 * term using the span tag.  GradientFormatter uses a bgcolor argument to the font tag which
 * doesn't work in Mozilla, thus this class.
 * @see GradientFormatter

public class SpanGradientFormatter
	extends GradientFormatter
	public SpanGradientFormatter(float maxScore, String minForegroundColor,
            String maxForegroundColor, String minBackgroundColor,
            String maxBackgroundColor)
		super( maxScore, minForegroundColor,
			   maxForegroundColor, minBackgroundColor,

	public String highlightTerm(String originalText, TokenGroup tokenGroup)
        if (tokenGroup.getTotalScore() == 0)
            return originalText;
        float score = tokenGroup.getTotalScore();
        if (score == 0)
            return originalText;

		// try to size sb correctly
        StringBuilder sb = new StringBuilder( originalText.length() + EXTRA);
		sb.append("<span style=\""); 
		if (highlightForeground) 
			sb.append("color: "); 
			sb.append("; "); 
		if (highlightBackground)
			sb.append("background: ");
			sb.append("; ");
        return sb.toString();

	// guess how much extra text we'll add to the text we're highlighting to try to avoid a  StringBuilder resize
	private static final String TEMPLATE = "<span style=\"background: #EEEEEE; color: #000000;\">...";
	private static final int EXTRA = TEMPLATE.length();	

Other Lucene examples (source code examples)

Here is a short list of links related to this Lucene SpanGradientFormatter.java source code file:

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