org.apache.lucene.search.highlight.SimpleFragmenter.java Source code

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Here is the source code for org.apache.lucene.search.highlight.SimpleFragmenter.java

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/*
 * 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,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.lucene.search.highlight;

import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;

/**
 * {@link Fragmenter} implementation which breaks text up into same-size
 * fragments with no concerns over spotting sentence boundaries.
 */
public class SimpleFragmenter implements Fragmenter {
    private static final int DEFAULT_FRAGMENT_SIZE = 100;
    private int currentNumFrags;
    private int fragmentSize;
    private OffsetAttribute offsetAtt;

    public SimpleFragmenter() {
        this(DEFAULT_FRAGMENT_SIZE);
    }

    /**
     * 
     * @param fragmentSize size in number of characters of each fragment
     */
    public SimpleFragmenter(int fragmentSize) {
        this.fragmentSize = fragmentSize;
    }

    /* (non-Javadoc)
     * @see org.apache.lucene.search.highlight.Fragmenter#start(java.lang.String, org.apache.lucene.analysis.TokenStream)
     */
    @Override
    public void start(String originalText, TokenStream stream) {
        offsetAtt = stream.addAttribute(OffsetAttribute.class);
        currentNumFrags = 1;
    }

    /* (non-Javadoc)
     * @see org.apache.lucene.search.highlight.Fragmenter#isNewFragment()
     */
    @Override
    public boolean isNewFragment() {
        boolean isNewFrag = offsetAtt.endOffset() >= (fragmentSize * currentNumFrags);
        if (isNewFrag) {
            currentNumFrags++;
        }
        return isNewFrag;
    }

    /**
     * @return size in number of characters of each fragment
     */
    public int getFragmentSize() {
        return fragmentSize;
    }

    /**
     * @param size size in characters of each fragment
     */
    public void setFragmentSize(int size) {
        fragmentSize = size;
    }

}