| /* |
| * 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.solr.highlight; |
| |
| import java.util.regex.Pattern; |
| |
| import org.apache.lucene.search.highlight.Fragmenter; |
| import org.apache.lucene.search.highlight.NullFragmenter; |
| import org.apache.solr.common.params.HighlightParams; |
| import org.apache.solr.common.params.SolrParams; |
| import org.apache.solr.common.util.NamedList; |
| |
| /** |
| * {@link org.apache.lucene.search.highlight.Fragmenter} that tries to produce snippets that "look" like a regular |
| * expression. |
| * |
| * <code>solrconfig.xml</code> parameters: |
| * <ul> |
| * <li><code>hl.regex.pattern</code>: regular expression corresponding to "nice" fragments.</li> |
| * <li><code>hl.regex.slop</code>: how far the fragmenter can stray from the ideal fragment size. |
| A slop of 0.2 means that the fragmenter can go over or under by 20%.</li> |
| * <li><code>hl.regex.maxAnalyzedChars</code>: how many characters to apply the |
| regular expression to (independent from the global highlighter setting).</li> |
| * </ul> |
| * |
| * NOTE: the default for <code>maxAnalyzedChars</code> is much lower for this |
| * fragmenter. After this limit is exhausted, fragments are produced in the |
| * same way as <code>GapFragmenter</code> |
| */ |
| |
| public class RegexFragmenter extends HighlightingPluginBase implements SolrFragmenter |
| { |
| protected String defaultPatternRaw; |
| protected Pattern defaultPattern; |
| |
| @Override |
| public void init(@SuppressWarnings({"rawtypes"})NamedList args) { |
| super.init(args); |
| defaultPatternRaw = LuceneRegexFragmenter.DEFAULT_PATTERN_RAW; |
| if( defaults != null ) { |
| defaultPatternRaw = defaults.get(HighlightParams.PATTERN, LuceneRegexFragmenter.DEFAULT_PATTERN_RAW); |
| } |
| defaultPattern = Pattern.compile(defaultPatternRaw); |
| } |
| |
| @Override |
| public Fragmenter getFragmenter(String fieldName, SolrParams params ) |
| { |
| numRequests.inc(); |
| params = SolrParams.wrapDefaults(params, defaults); |
| |
| int fragsize = params.getFieldInt( fieldName, HighlightParams.FRAGSIZE, LuceneRegexFragmenter.DEFAULT_FRAGMENT_SIZE ); |
| int increment = params.getFieldInt( fieldName, HighlightParams.INCREMENT, LuceneRegexFragmenter.DEFAULT_INCREMENT_GAP ); |
| float slop = params.getFieldFloat( fieldName, HighlightParams.SLOP, LuceneRegexFragmenter.DEFAULT_SLOP ); |
| int maxchars = params.getFieldInt( fieldName, HighlightParams.MAX_RE_CHARS, LuceneRegexFragmenter.DEFAULT_MAX_ANALYZED_CHARS ); |
| String rawpat = params.getFieldParam( fieldName, HighlightParams.PATTERN, LuceneRegexFragmenter.DEFAULT_PATTERN_RAW ); |
| |
| Pattern p = rawpat == defaultPatternRaw ? defaultPattern : Pattern.compile(rawpat); |
| |
| if( fragsize <= 0 ) { |
| return new NullFragmenter(); |
| } |
| |
| return new LuceneRegexFragmenter( fragsize, increment, slop, maxchars, p ); |
| } |
| |
| |
| /////////////////////////////////////////////////////////////////////// |
| //////////////////////// SolrInfoMBeans methods /////////////////////// |
| /////////////////////////////////////////////////////////////////////// |
| |
| @Override |
| public String getDescription() { |
| return "RegexFragmenter (" + defaultPatternRaw + ")"; |
| } |
| } |