http://lucene.apache.org/lucene-parent/lucene-highlighter: This is the highlighter for apache lucene java (The Apache Software Foundation) 
/*
 * 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,
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 * See the License for the specific language governing permissions and
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package org.apache.lucene.search.uhighlight;


Creates a formatted snippet from the top passages.

@lucene.experimental
/**
 * Creates a formatted snippet from the top passages.
 *
 * @lucene.experimental
 */
public abstract class PassageFormatter {

  
Formats the top passages from content
into a human-readable text snippet.

Params:
  • passages – top-N passages for the field. Note these are sorted in
                the order that they appear in the document for convenience.
  • content –  content for the field.
Returns:formatted highlight. Note that for the non-expert APIs in UnifiedHighlighter that return String, the toString method on the Object returned by this method is used to compute the string.
/**
   * Formats the top <code>passages</code> from <code>content</code>
   * into a human-readable text snippet.
   *
   * @param passages top-N passages for the field. Note these are sorted in
   *                 the order that they appear in the document for convenience.
   * @param content  content for the field.
   * @return formatted highlight.  Note that for the
   * non-expert APIs in {@link UnifiedHighlighter} that
   * return String, the toString method on the Object
   * returned by this method is used to compute the string.
   */
  public abstract Object format(Passage passages[], String content);

}